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1.  Record linkage research and informed consent: who consents? 
Linking computerized health insurance records with routinely collected survey data is becoming increasingly popular in health services research. However, if consent is not universal, the requirement of written informed consent may introduce a number of research biases. The participants of a national health survey in Taiwan were asked to have their questionnaire results linked to their national health insurance records. This study compares those who consented with those who refused.
A national representative sample (n = 14,611 adults) of the general adult population aged 20 years or older who participated in the Taiwan National Health Interview Survey (NHIS) and who provided complete survey information were used in this study. At the end of the survey, the respondents were asked if they would give permission to access their National Health Insurance records. Information given by the interviewees in the survey was used to analyze who was more likely to consent to linkage and who wasn't.
Of the 14,611 NHIS participants, 12,911 (88%) gave consent, and 1,700 (12%) denied consent. The elderly, the illiterate, those with a lower income, and the suburban area residents were significantly more likely to deny consent. The aborigines were significantly less likely to refuse. No discrepancy in gender and self-reported health was found between individuals who consented and those who refused.
This study is the first population-based study in assessing the consent pattern in a general Asian population. Consistent with people in Western societies, in Taiwan, a typical Asian society, a high percentage of adults gave consent for their health insurance records and questionnaire results to be linked. Consenters differed significantly from non-consenters in important aspects such as age, ethnicity, and educational background. Consequently, having a high consent rate (88%) may not fully eliminate the possibility of selection bias. Researchers should take this source of bias into consideration in their study design and investigate any potential impact of this source of bias on their results.
PMCID: PMC1802736  PMID: 17291357
2.  Predictors of non-response in a UK-wide cohort study of children's accelerometer-determined physical activity using postal methods 
BMJ Open  2013;3(3):e002290.
To investigate the biological, social, behavioural and environmental factors associated with non-consent, and non-return of reliable accelerometer data (≥2 days lasting ≥10 h/day), in a UK-wide postal study of children's activity.
Nationally representative prospective cohort study.
Children born across the UK, between 2000 and 2002.
13 681 7 to 8-year-old singleton children who were invited to wear an accelerometer on their right hip for 7 consecutive days. Consenting families were posted an Actigraph GT1M accelerometer and asked to return it by post.
Primary outcome measures
Study consent and reliable accelerometer data acquisition.
Consent was obtained for 12 872 (94.5%) interviewed singletons, of whom 6497 (50.5%) returned reliable accelerometer data. Consent was less likely for children with a limiting illness or disability, children who did not have people smoking near them, children who had access to a garden, and those who lived in Northern Ireland. From those who consented, reliable accelerometer data were less likely to be acquired from children who: were boys; overweight/obese; of white, mixed or ‘other’ ethnicity; had an illness or disability limiting daily activity; whose mothers did not have a degree; who lived in rented accommodation; who exercised once a week or less; who had been breastfed; were from disadvantaged wards; had younger mothers or lone mothers; or were from households with just one, or more than three children.
Studies need to encourage consent and reliable data return in the wide range of groups we have identified to improve response and reduce non-response bias. Additional efforts targeted at such children should increase study consent and data acquisition while also reducing non-response bias. Adjustment must be made for missing data that account for missing data as a non-random event.
PMCID: PMC3612744  PMID: 23457328
3.  Associations between Mode of HIV Testing and Consent, Confidentiality, and Referral: A Comparative Analysis in Four African Countries 
PLoS Medicine  2012;9(10):e1001329.
A study carried out by Carla Obermeyer and colleagues examines whether practices regarding consent, confidentiality, and referral vary depending on whether HIV testing is provided through voluntary counseling and testing or provider-initiated testing.
Recommendations about scaling up HIV testing and counseling highlight the need to provide key services and to protect clients' rights, but it is unclear to what extent different modes of testing differ in this respect. This paper examines whether practices regarding consent, confidentiality, and referral vary depending on whether testing is provided through voluntary counseling and testing (VCT) or provider-initiated testing.
Methods and Findings
The MATCH (Multi-Country African Testing and Counseling for HIV) study was carried out in Burkina Faso, Kenya, Malawi, and Uganda. Surveys were conducted at selected facilities. We defined eight outcome measures related to pre- and post-test counseling, consent, confidentiality, satisfactory interactions with providers, and (for HIV-positive respondents) referral for care. These were compared across three types of facilities: integrated facilities, where testing is provided along with medical care; stand-alone VCT facilities; and prevention of mother-to-child transmission (PMTCT) facilities, where testing is part of PMTCT services. Tests of bivariate associations and modified Poisson regression were used to assess significance and estimate the unadjusted and adjusted associations between modes of testing and outcome measures. In total, 2,116 respondents tested in 2007 or later reported on their testing experience. High percentages of clients across countries and modes of testing reported receiving recommended services and being satisfied. In the unadjusted analyses, integrated testers were less likely to meet with a counselor before testing (83% compared with 95% of VCT testers; p<0.001), but those who had a pre-test meeting were more likely to have completed consent procedures (89% compared with 83% among VCT testers; p<0.001) and pre-test counseling (78% compared with 73% among VCT testers; p = 0.015). Both integrated and PMTCT testers were more likely to receive complete post-test counseling than were VCT testers (59% among both PMTCT and integrated testers compared with 36% among VCT testers; p<0.001). Adjusted analyses by country show few significant differences by mode of testing: only lower satisfaction among integrated testers in Burkina Faso and Uganda, and lower frequency of referral among PMTCT testers in Malawi. Adjusted analyses of pooled data across countries show a higher likelihood of pre-test meeting for those testing at VCT facilities (adjusted prevalence ratio: 1.22, 95% CI: 1.07–1.38) and higher satisfaction for stand-alone VCT facilities (adjusted prevalence ratio: 1.15; 95% CI: 1.06–1.25), compared to integrated testing, but no other associations were statistically significant.
Overall, in this study most respondents reported favorable outcomes for consent, confidentiality, and referral. Provider-initiated ways of delivering testing and counseling do not appear to be associated with less favorable outcomes for clients than traditional, client-initiated VCT, suggesting that testing can be scaled up through multiple modes without detriment to clients' rights.
Please see later in the article for the Editors' Summary
Editors' Summary
In 2007, World Health Organization (WHO) and the Joint United Nations Programme on HIV/AIDS (UNAIDS) issued a joint guidance document on “provider-initiated” HIV testing and counseling. They noted that previous testing strategies that relied on “client-initiated” testing (also referred to as VCT, for voluntary counseling and testing) had failed to reach enough people, both in high-income and resource-constrained countries—in Africa, for example, at that time, just 12% of men and 10% of women had ever been tested. They argued that many opportunities to diagnose and counsel people that visit health facilities for other reasons are being missed, and that provider-initiated HIV testing and counseling can help expand access to HIV treatment, care, and support. They made it clear, however, that mandatory testing is not acceptable. All provider-initiated testing must therefore give individuals the option to not be tested. In addition, the guidelines stressed that all testing must continue to observe “the three Cs” (informed consent, counseling, and confidentiality) and be accompanied by an “enabling environment” including the availability of antiretroviral therapy, prevention and support services, and a supportive social, policy, and legal framework. A number of advocates have subsequently criticized the guidelines for failing to recognize that health-care services and staff in some countries do not always observe the three Cs. Critics have also questioned the appropriateness of the strategy for settings where antiretroviral therapy is not always available or where stigma and discrimination remain widespread.
Why Was This Study Done?
To inform the debate surrounding scale-up of HIV testing in general and provider-initiated testing in particular with data on “real-life” testing, researchers have since carried out a number of studies. One of them, called MATCH (for Multi-Country African Testing and Counseling for HIV), was designed to allow systematic comparisons across African countries of different ways of HIV testing. Its goal was to investigate the uptake of testing, to analyze differences in the experience of testing across countries and modes of testing, and to use the results to devise better strategies to increase knowledge of HIV status and referral to care. MATCH used different means to collect information, including surveys and interviews. People from Burkina Faso, Kenya, Malawi, and Uganda participated. Some had undergone HIV testing, others had not. This study used a subset of the survey data collected for the MATCH study and asked whether there were systematic differences depending on the type of testing people had experienced.
What Did the Researchers Do and Find?
The data the researchers used were from 2,116 people who had undergone testing in the two previous years at different facilities in the four countries. The different facilities were grouped into three “modes” of testing: VCT-only testing, integrated testing (which included hospitals and other medical facilities where provider-initiated and client-initiated testing were both available, along with other medical services), and prevention of mother-to-child transmission (PMTCT) testing at medical facilities offering services to pregnant women. Analyzing the survey responses, the researchers categorized them as related to eight different “outcomes”: pre-test meeting, pre-test counseling, consent, confidentiality, satisfaction with the person-to-person interactions, post-test meeting to receive results, post-test counseling, and referral to care.
They found that across countries and different facilities, the majority of participants reported having received most of the testing-related services. More than 90% reported having a pre-test meeting, and around 80% were satisfied with the personal interactions, with the consent process, and with confidentiality. About 50% of participants reported receiving all post-test services, and 71% of those who had tested positive for HIV reported appropriate referral to care.
When they looked for differences between different modes of testing, the researchers found that while they existed, they did not consistently favor one mode over another. Some outcomes scored higher in VCT facilities, some in PMTCT facilities, and some in integrated facilities.
What Do These Findings Mean?
While there is room for improvement in HIV testing services (especially post-test services) across the countries and facilities included, the study did not reveal major problems with consent or confidentiality. The results also suggest that services at PMTCT and integrated facilities are not any worse than those at VCT-only sites. It seems therefore reasonable to continue expanding access to HIV testing and to include all facilities in the scale-up. That said, this is only one of a number of studies examining issues surrounding HIV testing, and decisions should be based on all available evidence. The results here are consistent with some of the other studies, but there are also reports that counseling might become neglected as testing is scaled up, and that offering testing routinely at every doctor's visit makes it seem mandatory even if there is the possibility to “opt out.” Other analyses of the MATCH study use in-depth interviews to understand in more detail the feelings, experiences, and attitudes of participants who have been tested as well as those who have not been tested. It will be important to see whether their results are consistent with the ones here, which are based on a survey of people who have been tested.
Additional Information
Please access these websites via the online version of this summary at
WHO has published a toolkit for scaling up HIV testing and counseling services in resource-limited settings, as well as the report Service Delivery Approaches to HIV Testing and Counselling (HSC): A Strategic HTC Programme Framework
In response to reactions to the 2007 joint WHO/UNAIDS guidelines Guidance on Provider-Initiated HIV Testing and Counselling in Health Facilities, the UNAIDS Reference Group on HIV and Human Rights issued a Statement and Recommendations on Scaling up HIV Testing and Counselling
The NAM/aidsmap website has a section on HIV testing policies and guidelines.
PMCID: PMC3479110  PMID: 23109914
4.  When "no" might not quite mean "no"; the importance of informed and meaningful non-consent: results from a survey of individuals refusing participation in a health-related research project 
Low participation rates can lead to sampling bias, delays in completion and increased costs. Strategies to improve participation rates should address reasons for non-participation. However, most empirical research has focused on participants' motives rather than the reasons why non-participants refuse to take part. In this study we investigated the reasons why older people choose not to participate in a research project.
Follow-up study of people living in Tayside, Scotland who had opted-out of a cross-sectional survey on activities in retirement. Eight hundred and eighty seven people aged 65–84 years were invited to take part in a home-based cross-sectional survey. Of these, 471 refused to take part. Permission was obtained to follow-up 417 of the refusers. Demographic characteristics of people who refused to take part and the reasons they gave for not taking part were collected.
54% of those invited to take part in the original cross-sectional survey refused to do so. However, 61% of these individuals went on to participate in the follow-up study and provided reasons for their original refusal. For the vast majority of people initial non-participation did not reflect an objection to participating in research in principle but frequently stemmed from barriers or misunderstandings about the nature or process of the project itself. Only 28% indicated that they were "not interested in research". The meaningfulness of expressions of non-consent may therefore be called into question. Hierarchical log-linear modelling showed that refusal was independently influenced by age, gender and social class. However, this response pattern was different for the follow-up study in which reasons for non-participation in the first survey were sought. This difference in pattern and response rates supports the likely importance of recruitment issues that are research and context specific.
An expression of non-consent does not necessarily mean that a fully informed evaluation of the pros and cons of participation and non-participation has taken place. The meaningfulness of expressions of non-consent may therefore be a cause for concern and should be subject to further research. Many reasons for non-participation may be specific to a particular research topic or population. Information sheets should reflect this by going beyond standardised guidelines for their design and instead proactively seek out and address areas of concern or potential misunderstanding. The use of established behavioural theory in their design could also be considered.
PMCID: PMC1866231  PMID: 17462081
5.  Investigating non-response bias in a survey of disablement in the community: implications for survey methodology. 
STUDY OBJECTIVE--The aim was to investigate the pattern of age specific non-response bias in a two phase survey of disablement in the community. It seeks to examine patterns of response in different age groups to a household based postal questionnaire, and the implication of such trends for the estimation of prevalence of reported dependence. It also looks at the effect that the readiness to respond during the first phase postal questionnaire had on participation in the interview based second phase of the study. DESIGN AND SETTING--A two stage survey of disablement in the population was undertaken. A first phase postal questionnaire was sent to 25,168 households in Calderdale, West Yorkshire, England, to ascertain the prevalence of physical disability. The second phase comprised in depth interviews with a sample of individuals identified in the first phase as being disabled. RESPONDENTS--A total of 21,889 postal questionnaires were returned (87%) representing households containing 42,826 people aged 16 years and over. A disproportionately stratified random sample of 950 respondents reporting disability was taken for the second phase. Of these 891 were still available, and 838 (94%) were interviewed. MEASUREMENTS AND MAIN RESULTS--A study of the timing of response to a postal questionnaire showed that patterns differed for different age groups. The estimated prevalence of those aged 65 years and over who were dependent was steady over time whereas for those in the 16-64 age range the estimated prevalence fell as the survey progressed, indicating a tendency for those who were dependent to respond sooner. Examination of the relationship of responses at phase 1 and phase 2 showed that response to invitation to interview was much less in those who had responded later, and presumably more reluctantly, in the first phase. CONCLUSIONS--These findings raise questions about how different patterns of response might be indicative of bias which could differentially affect final age specific prevalence estimates. They also have methodological implications for the follow up of reluctant responders both to increase the response rate and to secure cooperation in the second phase of a two phase survey.
PMCID: PMC1060767  PMID: 1836811
6.  Demographic characteristics and health behaviours of consenters to medical examination. Results from the Welsh Heart Health Survey. 
STUDY OBJECTIVE--The aim was to compare the demographic characteristics and health related behaviours of people who consented to a medical examination as part of a population survey with those who did not. STUDY DESIGN--The study formed part of the (1985) Welsh Heart Health Survey, which comprised a three stage design involving household interview, self completion questionnaire, and medical examination. Subjects for medical examination were selected from responders to the questionnaire survey (67%). Sixty six per cent of this group consented to medical examination (n = 11,637). Odds ratio analysis techniques were used to compare consenters and non-consenters. MEASUREMENTS AND MAIN RESULTS--The analysis was based on self reported information available from previously completed questionnaires, and from personal interviews. The study supported the findings of previous research indicating that consenters to medical examination are more likely to be from non-manual social groups, to be aged 25-44 years, to be educated beyond school age, and to be married. Individuals with healthy lifestyle characteristics (diet, physical activity) were overrepresented among consenters. The only exception to this finding was in relation to excessive alcohol consumption. CONCLUSIONS--These findings emphasise the importance of maximising response rates in all forms of social research including surveys with a clinical component. They also have methodological and analytical implications for the Welsh Heart Health Survey.
PMCID: PMC1059619  PMID: 1431726
7.  Patient Attitudes Regarding Consent for Emergency Department Computed Tomographies 
Little is known about patient attitudes towards informed consent for computed tomography (CT) in the emergency department (ED). We set out to determine ED patient attitudes about providing informed consent for CTs.
In this cross-sectional questionnaire-based survey study, we evaluated a convenience sample of patients’ attitudes about providing informed consent for having a CT at 2 institutional sites. Historically, at our institutional network, patients received a CT at approximately 25% of their ED visits. The survey consisted of 17 “yes/no” or multiple-choice questions. The primary outcome question was “which type of informed consent do you feel is appropriate for a CT in the Emergency Department?”
We analyzed 300 survey responses, which represented a 90% return rate of surveys distributed. Seventy-seven percent thought they should give their consent prior to receiving a CT, and 95% were either comfortable or very comfortable with their physician making the decision regarding whether they needed a CT. Forty percent of the patients felt that a general consent was appropriate before receiving a CT in the ED, while 34% thought a verbal consent was appropriate and 15% percent thought a written consent was appropriate. Seventy-two percent of the ED patients didn’t expect to receive a CT during their ED visit and 30% of the ED patients had previously provided consent prior to receiving a CT.
Most patients feel comfortable letting the doctor make the decision regarding the need for a CT. Most ED patients feel informed consent should occur before receiving a CT but only a minority feel the consent should be written and specific to the test.
PMCID: PMC3935784  PMID: 24578764
8.  “Let’s get the best quality research we can”: public awareness and acceptance of consent to use existing data in health research: a systematic review and qualitative study 
Opt-in consent is usually required for research, but is known to introduce selection bias. This is a particular problem for large scale epidemiological studies using only pre-collected health data. Most previous studies have shown that members of the public value opt-in consent and can perceive research without consent as an invasion of privacy. Past research has suggested that people are generally unaware of research processes and existing safeguards, and that education may increase the acceptability of research without prior informed consent, but this recommendation has not been formally evaluated. Our objectives were to determine the range of public opinion about the use of existing medical data for research and to explore views about consent to a secondary review of medical records for research. We also investigated the effect of the provision of detailed information about the potential effect of selection bias on public acceptability of the use of data for research.
We carried out a systematic review of existing literature on public attitudes to secondary use of existing health records identified by searching PubMed (1966-present), Embase (1974-present) and reference lists of identified studies to provide a general overview, followed by a qualitative focus group study with 19 older men recruited from rural and suburban primary care practices in the UK to explore key issues in detail.
The systematic review identified twenty-seven relevant papers and the findings suggested that males and older people were more likely to consent to a review of their medical data. Many studies noted participants’ lack of knowledge about research processes and existing safeguards and this was reflected in the focus groups. Focus group participants became more accepting of the use of pre-collected medical data without consent after being given information about selection bias and research processes. All participants were keen to contribute to NHS-related research but some were concerned about data-sharing for commercial gain and the potential misuse of information.
Increasing public education about research and specific targeted information provision could promote trust in research processes and safeguards, which in turn could increase the acceptability of research without specific consent where the need for consent would lead to biased findings and impede research necessary to improve public health.
PMCID: PMC3682867  PMID: 23734773
Medical record; Informed consent; Selection bias; Secondary research; Confidentiality
9.  Obtaining subjects’ consent to publish identifying personal information: current practices and identifying potential issues 
BMC Medical Ethics  2013;14:47.
In studies publishing identifying personal information, obtaining consent is regarded as necessary, as it is impossible to ensure complete anonymity. However, current journal practices around specific points to consider when obtaining consent, the contents of consent forms and how consent forms are managed have not yet been fully examined. This study was conducted to identify potential issues surrounding consent to publish identifying personal information.
Content analysis was carried out on instructions for authors and consent forms developed by academic journals in four fields (as classified by Journal Citation Reports): medicine general and internal, genetics and heredity, pediatrics, and psychiatry. An online questionnaire survey of editors working for journals that require the submission of consent forms was also conducted.
Instructions for authors were reviewed for 491 academic journals (132 for medicine general and internal, 147 for genetics and heredity, 100 for pediatrics, and 112 for psychiatry). Approximately 40% (203: 74 for medicine general and internal, 31 for genetics and heredity, 58 for pediatrics, and 40 for psychiatry) stated that subject consent was necessary. The submission of consent forms was required by 30% (154) of the journals studied, and 10% (50) provided their own consent forms for authors to use. Two journals mentioned that the possible effects of publication on subjects should be considered. Many journal consent forms mentioned the difficulties in ensuring complete anonymity of subjects, but few addressed the study objective, the subjects’ right to refuse consent and the withdrawal of consent. The main reason for requiring the submission of consent forms was to confirm that consent had been obtained.
Approximately 40% of journals required subject consent to be obtained. However, differences were observed depending on the fields. Specific considerations were not always documented. There is a need to address issues around the study objective, subjects’ right to refuse consent and the withdrawal of consent. Whether responsibility for ensuring that the consent form has been signed lies with publishers also needs to be discussed.
PMCID: PMC4222768  PMID: 24267590
Consent; Consent forms; Identifying information
10.  Waiver of consent in non-interventional, observational emergency research: the PROMMTT experience 
In the PRospective Observational Multi-center Major Trauma Transfusion (PROMMTT) study, waiver of consent was utilized because previous literature reported low response rates and subsequent bias. The goal of this manuscript is to examine the rationale and tradeoffs of using waiver of consent in PROMMTT.
PROMMTT enrolled trauma patients receiving at least one unit of red blood cells within 6 hours after admission at ten US Level 1 Trauma Centers. Local Institutional Review Boards (IRBs) from all sites approved the study. Site 8 was required by their IRB to attempt consent, but was allowed to retain data on patients unable to be consented.
Of 121 subjects enrolled at Site 8, 55 consents were obtained (46%) and no patient or legally-authorized representative refused to give consent. Thirty-six (30%) patients died and 6 (5%) were discharged before consent could be attempted. Consent was attempted but not possible among 24 patients (20%). Of the 10 clinical sites, six of the local IRBs approved collection of residual blood samples, one had prior approval to collect timed blood samples under a separate protocol, and three reported that their local IRBs would not approve collection of residual blood under a waiver of consent.
Waiver of consent was used in PROMMTT because of the potential adverse impact of consent refusals; however, there were no refusals. If Site 8’s IRB had required withdrawal of patients unable to consent and destruction of their data, a serious bias would likely have been introduced. Other tradeoffs included a reduction in sites participating in residual blood collection, and a smaller than expected amount of residual blood collected among sites operating under a waiver of consent. Non-interventional emergency research studies should consider these potential tradeoffs carefully before deciding whether waiver of consent would best achieve the goals of a study.
Level of Evidence
Prospective, Level II
PMCID: PMC3744180  PMID: 23778508
PROMMTT; Massive transfusion; trauma; waiver of consent
11.  The feasibility of using a postal survey method to assess the health and development of 7 year old children of different birth weight 
STUDY OBJECTIVE: To test the feasibility of using a postal survey to assess health and development in 7 year old children of different birth weights and to examine the response and any resulting response bias. DESIGN: A multi-stage postal survey, using a sample stratified by birth weight. SETTING: The four counties of Oxfordshire, Buckinghamshire, Berkshire, and Northamptonshire, which make up the former Oxford NHS Region. SAMPLE: All children born in 1985 to the residents of the former Oxford region who weighed either under 1500 g or over 5000 g at birth and all those with unstated birth weight were included. Samples of approximately 130 live births were randomly selected from each 500 g birth weight band between 1500 g and 5000 g. The total sample size was 1319. METHODS: The children in the sample were identified from birth registration and traced through the National Health Service Central Register (NHSCR). Self administered questionnaires were sent through the relevant Family Health Service Authority (FHSA) and then via the child's general practitioner (GP) to the child's parent(s). When parents' permission was given, self administered questionnaires were also sent to the child's GP and teacher. MAIN RESULTS: Of the 1319 children, 1169 were alive at the age of 7 and were successfully traced. Questionnaires were forwarded by GPs to parents of 1071 children and completed questionnaires were obtained from parents of 805 children. Parents of 753 children gave permission to approach the child's teacher and replies were received for 695. Parents of 770 children gave permission to send a questionnaire to the child's GP and 724 were returned completed. Response bias was assessed for the parents' questionnaire using data recorded about all births at birth registration. Response rates varied by sex of child, social class, and country of birth of the father. In addition, parents with a child with a serious motor or sensory deficit appeared to be more likely to respond. CONCLUSIONS: Response rates at each stage of the survey were good. The bias in response to the parents' questionnaire needs to be taken into consideration in future work. The method was found to be feasible and could be applied more widely than in monitoring child health.
PMCID: PMC1756733  PMID: 9799878
12.  Increasing response to a postal survey of sedentary patients – a randomised controlled trial [ISRCTN45665423] 
A systematic review identified a range of methods, which can influence response rates. However, analysis specific to a healthcare setting, and in particular, involving people expected to be poor responders, was missing, We examined the effect of pre-warning letters on response rates to a postal survey of sedentary patients whom we expected a low rate of response.
Participants were randomised to receive a pre-warning letter or no pre-warning letter, seven days before sending the main questionnaire. The main questionnaire included a covering letter and pre-paid return envelope. After seven days, non-responders were sent a reminder letter and seven days later, another reminder letter with a further copy of the questionnaire and return envelope.
627 adults, with a mean age of 48 years (SD 13, range 18 to 78) of whom 69.2% (434/627) were women, were randomised. 49.0% (307/627) of patients were allocated to receive a pre-warning letter and 51.0% (320/627) no pre-warning letter, seven days in advance of posting the main questionnaire. The final response rate to the main questionnaire was 30.0% (92/307) amongst those sent a pre-warning letter and 20.9% (67/320) not sent a pre-warning letter, with an adjusted odds ratio of 1.60 (95% CI 1.1, 2.30).
The relatively low cost method of sending a pre-warning letter had a modest impact on increasing response rates to a postal questionnaire sent to a group of patients for whom a low response rate was anticipated. Investigators should consider incorporating this simple intervention when conducting postal surveys, to reduce the potential for nonresponse bias and to increase the study power. Methods other than postal surveys may be needed however when a low response rate to postal surveys is likely.
PMCID: PMC534787  PMID: 15537429
13.  Public opinion on systems for feeding back views to the National Health Service 
Quality & safety in health care  2003;12(6):435-442.
Objectives: To explore public opinions about different systems for feeding back views about health services to the National Health Service.
Design: Questionnaire survey.
Setting: NHS Grampian, Scotland, UK.
Participants: A random sample of 10 000 adults registered with a general practitioner in Grampian was invited to opt in to the study; 2449 were sent questionnaires.
Outcome measures: Opinions about different feedback mechanisms and their likely effectiveness in three scenarios; reasons for preferring particular mechanisms.
Results: Of 1951 respondents, over 80% thought patient representatives would be a good way for people to pass on their ideas about the NHS and would help to improve it. Patient representatives were the most widely preferred course of action for two out of three scenarios. People explained their preferences for particular feedback systems mainly in terms of their ease of use, the perception that they would be listened to, and the likelihood of anything being done about what they said. However, people varied in their judgements about the likely effectiveness of different feedback systems. Preferences for particular systems varied according to the types of situation considered. Some people are reluctant to approach clinical staff with concerns about healthcare quality. A substantial minority have no confidence that their concerns would be listened to or acted upon, however they were expressed.
Conclusion: The "patient representative" function has substantial popular support and could facilitate local learning and action to improve the quality of health services from users' perspectives. Feedback systems must demonstrate their effectiveness if they are to gain and retain public confidence.
PMCID: PMC1758035  PMID: 14645759
14.  Can clinicians benefit from patient satisfaction surveys? Evaluating the NSF for Older People, 2005–2006 
A transformation of healthcare is underway, from a sellers' market to a consumers' market, where the satisfaction of the patient's needs is part of the definition of quality. Patient satisfaction surveys are widely used to judge service quality, but clinicians are sceptical about them because they are too often poorly designed measures that do not lead to improvements in the quality of care.
To explore the use of patient satisfaction survey data in identifying problems with the provision of inpatient care for older people.
A case study using secondary analysis of postal survey data about older people's experiences of health and social care services, obtained during the evaluation of the National Service Framework for Older People in 2005–2006. The survey asked about experiences of inpatient care and of discharge from hospital, and sought perceptions of the avoidability of the admission.
Settings and participants
A total of 4170 people aged 50 years and over returned a postal questionnaire in six local authority areas of England. Responses from 584 who had experienced a recent overnight stay in hospital are reported and discussed.
The response rate was 35%, ranging from 26% to 44% in the six areas surveyed. The great majority of those who had recent direct experience of inpatient care reported that they had been engaged in decision-making, that staff promoted their independence and maintained their dignity. There were widespread examples, however, of the opposite experiences. Discharge from hospital was problematic for about one-third of survey respondents with this experience, and there were different accounts of poorly managed discharges from all areas.
Case studies using local survey data can be used as formative assessments of services. The response rate to the survey and the likelihood of responder bias mean that patient satisfaction survey data of this sort cannot be used to judge or compare services in a summative way, but can highlight areas where remedial action is needed. Small-scale local surveys may seem to lack the robustness of larger studies, but do identify similar areas of concern. Commissioners and clinicians could use the findings of such surveys to inform dialogues about the quality of hospital care for older people.
PMCID: PMC2625387  PMID: 19092030
15.  Investigating the proxy effect and the saliency principle in household based postal questionnaires. 
STUDY OBJECTIVE--The aim was to investigate two possible sources of bias inherent in using a household based postal questionnaire, the "proxy effect", inaccurate reporting about characteristics of others, and the "saliency principle", reporting of only the most salient features. This is of importance in surveys concerned with screening the population to identify individuals with certain characteristics, and so possibly relying on one member of the household to reply on behalf of all others. DESIGN AND SETTING--A two stage survey of disablement in the population was undertaken. A first phase postal questionnaire was sent to 25,168 households in Calderdale, West Yorkshire, England, to ascertain the prevalence of physical disability and of troubles with the joints. The second phase comprised in depth interviews with a sample of individuals identified in the first phase as being disabled. RESPONDENTS--A total of 21,889 postal questionnaires were returned (87%) representing households containing 42,826 people aged 16 years and over. A disproportionately stratified random sample of 950 respondents reporting disability was taken in the second phase. Of these 891 were still available, and 838 (94%) were interviewed. MEASUREMENTS AND MAIN RESULTS--The postal questionnaire found that almost 29% of those who lived "alone" (without another adult) reported some level of disability, compared to only 10% of those who lived with others. The difference remained significant after standardisation. This apparent underreporting or "proxy effect" was present for reporting about disability overall, but not for severe disability (dependence on help of others), which suggests the operation of the "saliency principle". Reporting on joint troubles appeared to be affected by the proxy effect both for any joint problems, and when more than five joints were affected. Analysis of a small set of postal questionnaires from respondents who reported joint problems only at interview and where we could identify who had completed the postal questionnaire supports the hypothesis of a proxy effect; two thirds of the original postal questionnaires had been completed by a proxy. The results were further complicated by an interaction between reporting of disability and joint troubles: the greater the level of disability, the less likely the reporting of joint troubles. CONCLUSIONS--The findings have general implications for studies involving postal household screening questionnaires, and raises additional concerns about those that are multitopic in content. In surveys of symptoms and minor disability, a proxy effect is likely to be operative. This effect is not apparent for obvious and long standing problems such as dependence on others for help. However the interaction between the reporting of disability and joint symptoms carries important implications for the development of multitopic postal screening questionnaires.
PMCID: PMC1059468  PMID: 1839034
16.  Knowledge & attitudes of mental health professionals regarding psychiatric research 
Background & objectives:
Mental health professionals have varied attitudes and views regarding informed consent and confidentiality protections in psychiatric research and clinical care. The present study was designed to understand the knowledge and views of mental health professionals (MHPs) regarding informed consent and confidentiality protection practices.
Mental health professionals (n=121) who were members of the Delhi Psychiatric Society, were invited to participate in this questionnaire-based study of their knowledge and attitudes regarding informed consent and confidentiality. Half of them expressed willingness to discuss participation and gave initial oral consent (n=62); of these, 31 gave written informed consent to participate and completed the questionnaires. The questionnaires included both forced choice (yes / no / do not know) and open-ended questions. Questionnaires content reflected prominent guidelines on informed consent and confidentiality protection.
Attitudes of the majority of the participants towards informed consent and confidentiality were in line with ethical principles and guidelines. All expressed the opinion that confidentiality should generally be respected and that if confidentiality was breached, there could be mistrust of the professional by the patient/participant. The mean knowledge scores regarding informed consent and confidentiality were 8.55 ± 1.46 and 8.16 ± 1.29, respectively.
Interpretation & conclusions:
The participating mental health professionals appeared to have adequate knowledge of basic ethical guidelines concerning informed consent and confidentiality. Most respondents were aware of ethical issues in research. Given the small sample size and low response rate, the significance of the quantitative analysis must be regarded with modesty, and qualitative analysis of open-ended questions may be more valuable for development of future research. Increased efforts to involve mental health professionals in research on ethical concerns pertinent to their work must be made, and the actual practices of these professionals with regard to ethical guidelines need to be studied.
PMCID: PMC4001336  PMID: 24718399
Confidentiality; ethical guidelines; informed consent; mental health professionals; mental health research
17.  Effects of a Financial Incentive on Health Researchers’ Response to an Online Survey: a Randomized Controlled Trial 
Nonresponse to questionnaires can affect the validity of surveys and introduce bias. Offering financial incentives can increase response rates to postal questionnaires, but the effect of financial incentives on response rates to online surveys is less clear.
As part of a survey, we aimed to test whether knowledge of a financial incentive would increase the response rate to an online questionnaire.
A randomized controlled trial of 485 UK-based principal investigators of publicly funded health services and population health research. Participants were contacted by email and invited to complete an online questionnaire via an embedded URL. Participants were randomly allocated to groups with either “knowledge of” or “no knowledge of” a financial incentive (£10 Amazon gift voucher) to be provided on completion of the survey. At the end of the study, gift vouchers were given to all participants who completed the questionnaire regardless of initial randomization status. Four reminder emails (sent from the same email address as the initial invitation) were sent out to nonrespondents at one, two, three, and four weeks; a fifth postal reminder was also undertaken. The primary outcome measure for the trial was the response rate one week after the second reminder. Response rate was also measured at the end of weeks one, two, three, four, and five, and after a postal reminder was sent.
In total, 243 (50%) questionnaires were returned (232 completed, 11 in which participation was declined). One week after the second reminder, the response rate in the “knowledge” group was 27% (66/244) versus 20% (49/241) in the “no knowledge” group (χ21 = 3.0, P = .08). The odds ratio for responding among those with knowledge of an incentive was 1.45 (95% confidence interval [CI] 0.95 - 2.21). At the third reminder, participants in the “no knowledge” group were informed about the incentive, ending the randomized element of the study. However we continued to follow up all participants, and from reminder three onwards, no significant differences were observed in the response rates of the two groups.
Knowledge of a financial incentive did not significantly increase the response rate to an online questionnaire. Future surveys should consider including a randomized element to further test the utility of offering incentives of other types and amounts to participate in online questionnaires.
Trial Registration
ISRCTN59912797; (Archived by WebCite at
PMCID: PMC2885780  PMID: 20457556
Questionnaires; Electronic Mail; Randomized Controlled Trial; Reminder Systems; reward
18.  A confidence interval approach to investigating non-response bias and monitoring response to postal questionnaires. 
STUDY OBJECTIVE--The aim was to develop an alternative method of investigating non-response bias in postal surveys, including a method of calculating a final full (100%) coverage confidence interval which avoids the wide intervals of existing approaches. DESIGN AND SETTING--As part of a two stage survey of disablement in the community, a first phase postal questionnaire was sent to 25,168 households in Calderdale, West Yorkshire, England. Confidence intervals were calculated to investigate the precision of estimates using a "no bias" model, where the prevalence in non-responders is assumed to be the same as in responders. RESPONDENTS--A total of 21,889 postal questionnaires were returned (87%), representing households containing 42,826 people aged 16 years and over. This was achieved by the original post (1st wave, 57% response); two further postal follow ups (2nd and 3rd waves, taking the response to 73% and 81% respectively), the latter including a small personal call back; and a final postal follow up (the 4th wave). RESULTS--The cumulative estimated prevalence of those with dependence was plotted as the survey progressed. The final wave full coverage estimated prevalence for those aged 16-64 years was 12.8 per 1000 with 95% confidence intervals of 11.3-14.4 per 1000. The integrity of this estimate holds as long as the true prevalence in non-responders is within the calculated non-response confidence interval under the no bias assumption, 9.7-16.0 per 1000 people. This latter interval represents the tolerance of prevalence in non-responders implied by the no bias assumption. CONCLUSIONS--The findings have general implications for monitoring non-response bias in postal screening questionnaires. The confidence interval approach developed in this paper offers an alternative to existing regression based estimates, giving an indication of the range of prevalence amongst non-responders that could be tolerated before the no bias assumption used by the model is breached. It is suggested that this approach can be used to determine both the extent of bias, and to aid decision making about the appropriate juncture to terminate follow up. It highlights the potential, particularly in the context of a computerised survey operation, of methodological investigation occurring simultaneously with survey operation.
PMCID: PMC1060708  PMID: 1828494
19.  The Effect of Low Survey Response Rates on Estimates of Alcohol Consumption in a General Population Survey 
PLoS ONE  2012;7(4):e35527.
Response rates for surveys of alcohol use are declining for all modes of administration (postal, telephone, face-to-face). Low response rates may result in estimates that are biased by selective non-response. We examined non-response bias in the NZ GENACIS survey, a postal survey of a random electoral roll sample, with a response rate of 49.5% (n = 1924). Our aim was to estimate the magnitude of non-response bias in estimating the prevalence of current drinking and heavy episodic (binge) drinking.
We used the “continuum of resistance” model to guide the investigation. In this model the likelihood of response by sample members is related to the amount of effort required from the researchers to elicit a response. First, the demographic characteristics of respondents and non-respondents were compared. Second, respondents who returned their questionnaire before the first reminder (early), before the second reminder (intermediate) or after the second reminder (late) were compared by demographic characteristics, 12-month prevalence of drinking and prevalence of binge drinking.
Demographic characteristics and prevalence of binge drinking were significantly different between late respondents and early/intermediate respondents, with the demographics of early and intermediate respondents being similar to people who refused to participate while late respondents were similar to all other non-respondents. Assuming non-respondents who did not actively refuse to participate had the same drinking patterns as late respondents, the prevalence of binge drinking amongst current drinkers was underestimated. Adjusting the prevalence of binge drinkers amongst current drinkers using population weights showed that this method of adjustment still resulted in an underestimate of the prevalence.
The findings suggest non-respondents who did not actively refuse to participate are likely to have similar or more extreme drinking behaviours than late respondents, and that surveys of health compromising behaviours such as alcohol use are likely to underestimate the prevalence of these behaviours.
PMCID: PMC3332039  PMID: 22532858
20.  Biobank research and ethics: the problem of informed consent in Polish biobanks 
The dynamic development of biobanks causes some ethical, social, and legal problems. The most discussed problems are obtaining informed consent, especially for future research, from minors and from deceased people. The aim of this article is to present the current standards held by Polish biobanks concerning obtaining a participant's informed consent in some aspects.
Material and methods
Survey was carried out by anonymous questionnaire among 59 institutions which deal with the collecting and storage of human cells and tissues in the year 2008. Twenty four filled-in copies of the questionnaires were sent back (return=41%).
Almost every institution (92%) obtains written consent, but a third of the surveyed institutions (29%) do not obtain consent for the future use of the samples. The majority of the respondents (83%) support the idea of using biological materials for research purposes of a donor who died if he did not leave any written objection to such practices and 46% of respondents stated that biobanks should obtain the consent from the already mature donor who gave their samples as a child.
The practice and rules for obtaining informed consent for the scientific research require improvement. The possibility to use the human materials in the future, conditions for getting access to the data, the possibility of their withdrawal from the database and using the materials and data after the death of the donor should be clearly determined when the informed consent to collect the material is obtained.
PMCID: PMC3258806  PMID: 22291838
biobanks; research ethics; informed consent; genetic collection; management
21.  Selection bias resulting from the requirement for prior consent in observational research: a community cohort of people with ischaemic heart disease 
Heart  2007;93(9):1116-1120.
To evaluate differences between adults who consent to participate in observational research and those who do not.
Prospective, population‐based cohort study.
35 randomised Irish general practices.
1609 adults with ischaemic heart disease identified in 2000–1.
Medical records search, postal questionnaire and consent form in 2005–6.
Main outcome measures
Differences in demographic and prognostic risk factors between consenters and non‐consenters.
At follow‐up, charts were located for 1592 patients (98.9%). Questionnaires were sent to 1269 patients and 876 were returned (69%). Of these, 574 (65.5%) gave consent for participation in further research. Logistic regression identified four characteristics as independently positively predictive of consent to participation in further research among questionnaire responders: having undergone percutaneous transluminal coronary angioplasty was associated with an increased odds of consent, with an odds ratio (OR) of 1.77 (95% CI 1.09 to 2.86), as was a last recorded blood pressure <140/90 mm Hg (OR = 1.45 (1.00 to 2.09)), a last recorded total cholesterol level <5 mmol/l (OR = 1.71 (1.16 to 2.54)) and being an ex‐smoker rather than a current smoker or non‐smoker (OR = 1.73 (1.17 to 2.57)).
This research demonstrates the potential impact of consent bias in observational research on ischaemic heart disease, a disease of everyday clinical importance in Europe. It demonstrates that clinically important prognostic variables may be associated with consent preferences. Future cohorts, dependent upon prior written consent, may contain disproportionate numbers of those who have made healthy lifestyle decisions, have previously benefited from treatment or whose clinical risk factors are already well managed. As a result, the generalisability of such research may be diminished and the effects of treatments over‐ or underestimated.
PMCID: PMC1955022  PMID: 17502325
selection bias; consent; observational research; ischaemic heart disease
22.  The Knee Clinical Assessment Study – CAS(K). A prospective study of knee pain and knee osteoarthritis in the general population: baseline recruitment and retention at 18 months 
Selective non-participation at baseline (due to non-response and non-consent) and loss to follow-up are important concerns for longitudinal observational research. We investigated these matters in the context of baseline recruitment and retention at 18 months of participants for a prospective observational cohort study of knee pain and knee osteoarthritis in the general population.
Participants were recruited to the Knee Clinical Assessment Study – CAS(K) – by a multi-stage process involving response to two postal questionnaires, consent to further contact and medical record review (optional), and attendance at a research clinic. Follow-up at 18-months was by postal questionnaire. The characteristics of responders/consenters were described for each stage in the recruitment process to identify patterns of selective non-participation and loss to follow-up. The external validity of findings from the clinic attenders was tested by comparing the distribution of WOMAC scores and the association between physical function and obesity with the same parameters measured directly in the target population as whole.
3106 adults aged 50 years and over reporting knee pain in the previous 12 months were identified from the first baseline questionnaire. Of these, 819 consented to further contact, responded to the second questionnaire, and attended the research clinics. 776 were successfully followed up at 18 months. There was evidence of selective non-participation during recruitment (aged 80 years and over, lower socioeconomic group, currently in employment, experiencing anxiety or depression, brief episode of knee pain within the previous year). This did not cause significant bias in either the distribution of WOMAC scores or the association between physical function and obesity.
Despite recruiting a minority of the target population to the research clinics and some evidence of selective non-participation, this appears not to have resulted in significant bias of cross-sectional estimates. The main effect of non-participation in the current cohort is likely to be a loss of precision in stratum-specific estimates e.g. in those aged 80 years and over. The subgroup of individuals who attended the research clinics and who make up the CAS(K) cohort can be used to accurately estimate parameters in the reference population as a whole. The potential for selection bias, however, remains an important consideration in each subsequent analysis.
PMCID: PMC1435895  PMID: 16542454
23.  Response rates and selection problems, with emphasis on mental health variables and DNA sampling, in large population-based, cross-sectional and longitudinal studies of adolescents in Norway 
BMC Public Health  2010;10:602.
Selection bias is a threat to the internal validity of epidemiological studies. In light of a growing number of studies which aim to provide DNA, as well as a considerable number of invitees who declined to participate, we discuss response rates, predictors of lost to follow-up and failure to provide DNA, and the presence of possible selection bias, based on five samples of adolescents.
We included nearly 7,000 adolescents from two longitudinal studies of 18/19 year olds with two corresponding cross-sectional baseline studies at age 15/16 (10th graders), and one cross-sectional study of 13th graders (18/19 years old). DNA was sampled from the cheek mucosa of 18/19 year olds. Predictors of lost to follow-up and failure to provide DNA were studied by Poisson regression. Selection bias in the follow-up at age 18/19 was estimated through investigation of prevalence ratios (PRs) between selected exposures (physical activity, smoking) and outcome variables (general health, mental distress, externalizing problems) measured at baseline.
Out of 5,750 who participated at age 15/16, we lost 42% at follow-up at age 18/19. The percentage of participants who gave their consent to DNA provision was as high as the percentage that consented to a linkage of data with other health registers and surveys, approximately 90%. Significant predictors of lost to follow-up and failure to provide DNA samples in the present genetic epidemiological study were: male gender; non-western ethnicity; postal survey compared with school-based; low educational plans; low education and income of father; low perceived family economy; unmarried parents; poor self-reported health; externalized symptoms and smoking, with some differences in subgroups of ethnicity and gender. The association measures (PRs) were quite similar among participants and all invitees, with some minor discrepancies in subgroups of non-western boys and girls.
Lost to follow-up had marginal impact on the estimated prevalence ratios. It is not likely that the invitation to provide DNA influenced the response rates of 18/19 year olds. Non-western ethnicity, male gender and characteristics related to a low social class and general and mental health problems measured at baseline are associated with lost to follow-up and failure to provide DNA.
PMCID: PMC2964627  PMID: 20939903
24.  How experience makes a difference: practitioners’ views on the use of deferred consent in paediatric and neonatal emergency care trials 
BMC Medical Ethics  2013;14:45.
In 2008 UK legislation was amended to enable the use of deferred consent for paediatric emergency care (EC) trials in recognition of the practical and ethical difficulties of obtaining prospective consent in an emergency situation. However, ambiguity about how to make deferred consent acceptable to parents, children and practitioners remains. In particular, little is known about practitioners’ views and experiences of seeking deferred consent in this setting.
As part of a wider study investigating consent methods in paediatric emergency care trials (called CONNECT), a 20 item online questionnaire was sent by email inviting practitioners (doctors and nurses) who were involved in talking with families about children’s and young people’s (aged 0–16 years) participation in UK EC trials. To ensure those with and without experience of deferred consent were included, practitioners were sampled using a combination of purposive and snowball sampling methods. Simple descriptive statistics were used to analyse the quantitative data, whilst the constant comparative method was used to analyse qualitative data. Elements of a symbiotic empirical ethics approach was used to integrate empirical evidence and bioethical literature to explore the data and draw practice orientated conclusions.
Views on deferred consent differed depending upon whether or not practitioners were experienced in this consent method. Practitioners who had no experience of deferred consent reported negative perceptions of this consent method; these practitioners were concerned about the impact that deferred consent would have upon the parent-practitioner relationship. In contrast, practitioners experienced in deferred consent described how families had been receptive to the consent method, if conducted sensitively and in a time appropriate manner. Experienced practitioners also described how deferred consent had improved recruitment, parental decision-making capacity and parent-practitioner relationships in the emergency care setting.
The views of practitioners with first-hand experience of deferred consent should be considered in the design and ethical review of future paediatric EC trials; the design and ethical review of such trials should not solely be informed by the beliefs of those without experience of using deferred consent. Further research involving parents and children is required to inform practitioner training and normative guidance on the use and appropriateness of deferred consent in emergency settings.
PMCID: PMC4228267  PMID: 24195717
25.  Changes Over Time in the Utilization of Disease-Related Internet Information in Newly Diagnosed Breast Cancer Patients 2007 to 2013 
As the number of people with Internet access rises, so does the use of the Internet as a potentially valuable source for health information. Insight into patient use of this information and its correlates over time may reveal changes in the digital divide based on patient age and education. Existing research has focused on patient characteristics that predict Internet information use and research on treatment context is rare.
This study aims to (1) present data on the proportion of newly diagnosed breast cancer patients treated in German breast centers from 2007 to 2013 who used the Internet for information on their disease, (2) look into correlations between Internet utilization and sociodemographic characteristics and if these change over time, and (3) determine if use of Internet information varies with the hospitals in which the patients were initially treated.
Data about utilization of the Internet for breast cancer–specific health information was obtained in a postal survey of breast cancer patients that is conducted annually in Germany with a steady response rate of 87% of consenting patients. Data from the survey were combined with data obtained by hospital personnel (eg, cancer stage and type of surgery). Data from 27,491 patients from 7 consecutive annual surveys were analyzed for this paper using multilevel regression modeling to account for clustering of patients in specific hospitals.
Breast cancer patients seeking disease-specific information on the Internet increased significantly from 26.96% (853/3164) in 2007 to 37.21% (1485/3991) in 2013. Similar patterns of demographic correlates were found for all 7 cohorts. Older patients (≥70 years) and patients with <10 years of formal education were less likely to use the Internet for information on topics related to their disease. Internet use was significantly higher among privately insured patients and patients living with a partner. Higher cancer stage and a foreign native language were associated with decreased use in the overall model. Type of surgery was not found to be associated with Internet use in the multivariable models. Intraclass correlation coefficients were small (0.00-0.03) suggesting only a small contribution of the hospital to the patients’ decision to use Internet information. There was no clear indication of a decreased digital divide based on age and education.
Use of the Internet for health information is on the rise among breast cancer patients. The strong age- and education-related differences raise the question of how relevant information can be adequately provided to all patients, especially to those with limited education, older age, and living without a partner.
PMCID: PMC4180359  PMID: 25158744
disease-related Internet information; digital divide; multilevel analysis; breast neoplasms; hospital differences

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