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1.  Prognostic models for stable coronary artery disease based on electronic health record cohort of 102 023 patients 
European heart journal  2013;35(13):844-852.
Aims
The population with stable coronary artery disease (SCAD) is growing but validated models to guide their clinical management are lacking. We developed and validated prognostic models for all-cause mortality and non-fatal myocardial infarction (MI) or coronary death in SCAD.
Methods and results
Models were developed in a linked electronic health records cohort of 102 023 SCAD patients from the CALIBER programme, with mean follow-up of 4.4 (SD 2.8) years during which 20 817 deaths and 8856 coronary outcomes were observed. The Kaplan–Meier 5-year risk was 20.6% (95% CI, 20.3, 20.9) for mortality and 9.7% (95% CI, 9.4, 9.9) for non-fatal MI or coronary death. The predictors in the models were age, sex, CAD diagnosis, deprivation, smoking, hypertension, diabetes, lipids, heart failure, peripheral arterial disease, atrial fibrillation, stroke, chronic kidney disease, chronic pulmonary disease, liver disease, cancer, depression, anxiety, heart rate, creatinine, white cell count, and haemoglobin. The models had good calibration and discrimination in internal (external) validation with C-index 0.811 (0.735) for all-cause mortality and 0.778 (0.718) for non-fatal MI or coronary death. Using these models to identify patients at high risk (defined by guidelines as 3% annual mortality) and support a management decision associated with hazard ratio 0.8 could save an additional 13-16 life years or 15-18 coronary event-free years per 1000 patients screened, compared with models with just age, sex, and deprivation.
Conclusion
These validated prognostic models could be used in clinical practice to support risk stratification as recommended in clinical guidelines.
doi:10.1093/eurheartj/eht533
PMCID: PMC3971383  PMID: 24353280
Stable coronary artery disease; Stable angina; Prognosis; Myocardial infarction; Electronic health records; CALIBER
2.  Prognostic models for stable coronary artery disease based on electronic health record cohort of 102 023 patients 
European Heart Journal  2013;35(13):844-852.
Aims
The population with stable coronary artery disease (SCAD) is growing but validated models to guide their clinical management are lacking. We developed and validated prognostic models for all-cause mortality and non-fatal myocardial infarction (MI) or coronary death in SCAD.
Methods and results
Models were developed in a linked electronic health records cohort of 102 023 SCAD patients from the CALIBER programme, with mean follow-up of 4.4 (SD 2.8) years during which 20 817 deaths and 8856 coronary outcomes were observed. The Kaplan–Meier 5-year risk was 20.6% (95% CI, 20.3, 20.9) for mortality and 9.7% (95% CI, 9.4, 9.9) for non-fatal MI or coronary death. The predictors in the models were age, sex, CAD diagnosis, deprivation, smoking, hypertension, diabetes, lipids, heart failure, peripheral arterial disease, atrial fibrillation, stroke, chronic kidney disease, chronic pulmonary disease, liver disease, cancer, depression, anxiety, heart rate, creatinine, white cell count, and haemoglobin. The models had good calibration and discrimination in internal (external) validation with C-index 0.811 (0.735) for all-cause mortality and 0.778 (0.718) for non-fatal MI or coronary death. Using these models to identify patients at high risk (defined by guidelines as 3% annual mortality) and support a management decision associated with hazard ratio 0.8 could save an additional 13–16 life years or 15–18 coronary event-free years per 1000 patients screened, compared with models with just age, sex, and deprivation.
Conclusion
These validated prognostic models could be used in clinical practice to support risk stratification as recommended in clinical guidelines.
doi:10.1093/eurheartj/eht533
PMCID: PMC3971383  PMID: 24353280
Stable coronary artery disease; Stable angina; Prognosis; Myocardial infarction; Electronic health records; CALIBER
3.  English to Arabic Translation of the Composite Abuse Scale (CAS): A Multi-Method Approach 
PLoS ONE  2013;8(9):e75244.
Background
The composite abuse scale (CAS) is a comprehensive tool used to measure intimate partner violence (IPV). The aim of the present study is to translate the CAS from English to Arabic.
Methods
The translation of the CAS was conducted in four stages using a multi-method approach: 1) preliminary forward translation, 2) discussion with a panel of bilingual experts, 3) focus groups discussion, and 4) back-translation of the CAS. The discussion included a linguistic validation by a comparison of the Arabic translation with the original English by assessing conceptual and content equivalence.
Findings
In all the stages of translation, there was an agreement to remove the question from the CAS that asked women about the use of objects in the vagina. Wording, format and order of the items were refined according to comments and suggestions made by the experts’ panel and focus groups’ members. The back-translated CAS showed similar wording and language of the original English version.
Conclusions
The Arabic version of the CAS will help to measure the problem of IPV among Saudi women and possibly other Arabic-speaking women in future studies. This is important, particularly, in longitudinal studies or intervention studies among abused women and it allows a comparison of the results of studies from different cultures. However, further validations studies are needed to ensure accurate and equivalent Arabic translation of the CAS.
doi:10.1371/journal.pone.0075244
PMCID: PMC3783446  PMID: 24086478
4.  Domestic violence: knowledge, attitudes, and clinical practice of selected UK primary healthcare clinicians 
The British Journal of General Practice  2012;62(602):e647-e655.
Background
Domestic violence affects one in four women and has significant health consequences. Women experiencing abuse identify doctors and other health professionals as potential sources of support. Primary care clinicians agree that domestic violence is a healthcare issue but have been reluctant to ask women if they are experiencing abuse.
Aim
To measure selected UK primary care clinicians’ current levels of knowledge, attitudes, and clinical skills in this area.
Design and setting
Prospective observational cohort in 48 general practices from Hackney in London and Bristol, UK.
Method
Administration of the Physician Readiness to Manage Intimate Partner Violence Survey (PREMIS), comprising five sections: responder profile, background (perceived preparation and knowledge), actual knowledge, opinions, and practice issues.
Results
Two hundred and seventy-two (59%) clinicians responded. Minimal previous domestic violence training was reported by participants. Clinicians only had basic knowledge about domestic violence but expressed a positive attitude towards engaging with women experiencing abuse. Many clinicians felt poorly prepared to ask relevant questions about domestic violence or to make appropriate referrals if abuse was disclosed. Forty per cent of participants never or seldom asked about abuse when a woman presented with injuries. Eighty per cent said that they did not have an adequate knowledge of local domestic violence resources. GPs were better prepared and more knowledgeable than practice nurses; they also identified a higher number of domestic violence cases.
Conclusion
Primary care clinicians’ attitudes towards women experiencing domestic violence are generally positive but they only have basic knowledge of the area. Both GPs and practice nurses need more comprehensive training on assessment and intervention, including the availability of local domestic violence services.
doi:10.3399/bjgp12X654623
PMCID: PMC3426604  PMID: 22947586
cross-sectional studies; domestic violence; primary health care; women
5.  Psychological advocacy toward healing (PATH): study protocol for a randomized controlled trial 
Trials  2013;14:221.
Background
Domestic violence and abuse (DVA), defined as threatening behavior or abuse by adults who are intimate partners or family members, is a key public health and clinical priority. The prevalence of DVA in the United Kingdom and worldwide is high, and its impact on physical and mental health is detrimental and persistent. There is currently little support within healthcare settings for women experiencing DVA. Psychological problems in particular may be difficult to manage outside specialist services, as conventional forms of therapy such as counseling that do not address the violence may be ineffective or even harmful. The aim of this study is to assess the overall effectiveness and cost-effectiveness of a novel psychological intervention tailored specifically for survivors of DVA and delivered by domestic violence advocates based in third-sector organizations.
Methods and study design
This study is an open, pragmatic, parallel group, individually randomized controlled trial. Women ages 16 years and older experiencing domestic violence are being enrolled and randomly allocated to receive usual DVA agency advocacy support (control) or usual DVA agency support plus psychological intervention (intervention). Those in the intervention group will receive eight specialist psychological advocacy (SPA) sessions weekly or fortnightly, with two follow-up sessions, 1 month and then 3 months later. This will be in addition to any advocacy support sessions each woman receives. Women in the control group will receive usual DVA agency support but no additional SPA sessions. The aim is to recruit 250 women to reach the target sample size. The primary outcomes are psychological well-being and depression severity at 1 yr from baseline, as measured by the Clinical Outcomes in Routine Evaluation–Outcome Measure (CORE-OM) and the Patient Health Questionnaire (PHQ-9), respectively. Secondary outcome measures include anxiety, posttraumatic stress, severity and frequency of abuse, quality of life and cost-effectiveness of the intervention. Data from a subsample of women in both groups will contribute to a nested qualitative study with repeat interviews during the year of follow-up.
Discussion
This study will contribute to the evidence base for management of the psychological needs of women experiencing DVA. The findings will have important implications for healthcare commissioners and providers, as well as third sector specialist DVA agencies providing services to this client group.
Trial registration
ISRCTN58561170
doi:10.1186/1745-6215-14-221
PMCID: PMC3718639  PMID: 23866771
6.  Longitudinal measurement of cortisol in association with mental health and experience of domestic violence and abuse: study protocol 
BMC Psychiatry  2013;13:188.
Background
Domestic violence and abuse is threatening behavior, violence/abuse used by one person to control the other within an intimate or family-type relationship. Women experience more severe physical and sexual domestic violence and abuse and more mental health consequences than men. The current study aims at exploring of the role of hypothalamic-pituitary-adrenocortical axis activity in abuse impact on women's mental health. Study objectives: 1) To evaluate diurnal cortisol slope, cortisol awakening response, and the mean cortisol concentration in women with a current or recent experience of abuse; 2) To estimate whether cortisol secretion is associated with type, severity, duration and cessation of abuse; 3) To investigate whether cortisol acts as mediator between abuse and mental health condition; 4) To examine whether there is any distinction in cortisol levels between those women exposed to both childhood abuse and domestic violence and abuse and those experienced only the latter. 4) To explore whether cortisol secretion differs between women living in refuge and those still living in the community.
Methods/Design
To meet study objectives 128 women will be recruited in a domestic violence agency and local communities. Baseline and 3-month follow-up measures will be taken over 6 months after recruitment. Each assessment will include: (1) standardized self-administered questionnaires to evaluate socio-demographics, experience of violence and abuse, mental and physical health; (2) weight and height measurement; (3) self-completion of wakening, post-wakening and evening saliva samples. Saliva will be analysed for cortisol and cortisone using Ultra performance liquid chromatography – tandem mass spectrometry.
We will compare diurnal cortisol parameters between non-abused controls and abuse survivors with and without mental health conditions. First following descriptive statistics for all the cortisol and mental health outcomes, relationships between them will be investigated using appropriate regression models. Second, these techniques will be used to investigate the extent to which cortisol measures act as potential mediators between type, severity, duration of abuse and mental disorders.
Discussion
Results of the study will increase our understanding of the pathophysiological mechanisms of abuse-related mental health disorders in women and inform researchers and practitioners on the possibility of using salivary cortisol as a biological marker for prognosis, diagnosis, and treatment evaluation among abuse survivors.
Trial registration
ClinicalTrials.gov registration NCT01632553
doi:10.1186/1471-244X-13-188
PMCID: PMC3716999  PMID: 23849084
Domestic violence; Partner abuse; Spousal abuse; Battered women; Abused women; Cortisol; Mental health; Depression; Anxiety; Posttraumatic stress disorder
7.  Domestic Violence and Perinatal Mental Disorders: A Systematic Review and Meta-Analysis 
PLoS Medicine  2013;10(5):e1001452.
Louise Howard and colleagues conduct a systematic review and meta-analysis to estimate the prevalence and odds of experience of domestic violence experience among women with antenatal and postnatal mental health disorders.
Please see later in the article for the Editors' Summary
Background
Domestic violence in the perinatal period is associated with adverse obstetric outcomes, but evidence is limited on its association with perinatal mental disorders. We aimed to estimate the prevalence and odds of having experienced domestic violence among women with antenatal and postnatal mental disorders (depression and anxiety disorders including post-traumatic stress disorder [PTSD], eating disorders, and psychoses).
Methods and Findings
We conducted a systematic review and meta-analysis (PROSPERO reference CRD42012002048). Data sources included searches of electronic databases (to 15 February 2013), hand searches, citation tracking, update of a review on victimisation and mental disorder, and expert recommendations. Included studies were peer-reviewed experimental or observational studies that reported on women aged 16 y or older, that assessed the prevalence and/or odds of having experienced domestic violence, and that assessed symptoms of perinatal mental disorder using a validated instrument. Two reviewers screened 1,125 full-text papers, extracted data, and independently appraised study quality. Odds ratios were pooled using meta-analysis.
Sixty-seven papers were included. Pooled estimates from longitudinal studies suggest a 3-fold increase in the odds of high levels of depressive symptoms in the postnatal period after having experienced partner violence during pregnancy (odds ratio 3.1, 95% CI 2.7–3.6). Increased odds of having experienced domestic violence among women with high levels of depressive, anxiety, and PTSD symptoms in the antenatal and postnatal periods were consistently reported in cross-sectional studies. No studies were identified on eating disorders or puerperal psychosis. Analyses were limited because of study heterogeneity and lack of data on baseline symptoms, preventing clear findings on causal directionality.
Conclusions
High levels of symptoms of perinatal depression, anxiety, and PTSD are significantly associated with having experienced domestic violence. High-quality evidence is now needed on how maternity and mental health services should address domestic violence and improve health outcomes for women and their infants in the perinatal period.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Domestic violence—physical, sexual, or emotional abuse by an intimate partner or family member—is a major public health problem and although more common in women, can also affect men. Due to the nature of the problem, it is difficult to collect accurate figures on the scale of domestic violence, but a study by the World Health Organization in ten countries found that 15%–71% of women aged 15–49 years reported physical and/or sexual violence by an intimate partner at some point in their lives. Women experiencing domestic violence have significant short- and long-term health problems, particularly regarding their mental health: experience of domestic violence can lead to a range of mental health disorders such as depression, psychosis, eating disorders, and even suicide attempts.
Why Was This Study Done?
As perinatal mental health disorders are among the commonest health problems in pregnancy and the postpartum period, and given the rate of domestic violence during pregnancy (previous studies have suggested a domestic violence prevalence of 4%–8% during pregnancy and the postnatal period), it is plausible that there may be a link between perinatal mental health disorders and having experienced domestic violence. Indeed, previous reviews have suggested the existence of such an association but were limited by the small number of included studies and focused on depression only, rather than the full range of antenatal and postnatal mental health disorders. So in this study the researchers systematically reviewed published studies to provide more robust estimates of the prevalence of having experienced domestic violence among women with antenatal and postnatal mental health disorders; the researchers also used a meta-analysis to estimate the odds (chance) of having experienced domestic violence among women with antenatal and postnatal mental health disorders.
What Did the Researchers Do and Find?
The researchers searched multiple databases and hand searched three relevant journals using key search terms to identify all types of relevant studies. Using specific criteria, the researchers retrieved and assessed over 1,000 full papers, of which 67 met the criteria for their systematic review. The researchers assessed the quality of each selected study and included only those studies that used validated diagnostic instruments and screening tools to assess mental health disorders in their calculations of the pooled (combined) odds ratio (OR) through meta-analysis.
Using these methods, in cross-sectional studies (studies conducted at one point in time), the researchers found that women with probable depression in the antenatal period reported a high prevalence and increased odds of having experienced partner violence during their lifetime (OR = 3), during the past year (OR = 2.8), and during pregnancy (OR = 5). The results were similar for the postnatal period. The evidence was less robust for anxiety disorders: among women with probable anxiety in the antenatal period, the researchers found an OR of 2.9 of having experienced lifetime partner violence. The odds were less in the postnatal period (OR = 1.4) In their analysis of longitudinal studies (follow-up studies over a period of time), the researchers found an increased odds of probable postnatal depression both among women who reported having ever experienced partner violence in their lifetime (OR = 2.9) and among women who reported having experienced partner violence during pregnancy (OR = 3.1). The researchers also found a combined prevalence estimate of 12.7% for probable depression during the postnatal period following experiences of partner violence during pregnancy. Because of limited data, the researchers could not calculate an OR of the association between probable antenatal depression and later experiences of partner violence.
What Do These Findings Mean?
These findings suggest that women with high levels of symptoms of perinatal mental health disorders—antenatal and postnatal anxiety, depression, and post-traumatic stress disorder—have a high prevalence and increased odds of having experienced domestic violence both over their lifetime and during pregnancy. However, these findings cannot prove causality, they fail to show a two-way association (that is, perinatal mental health disorders leading to subsequent domestic violence), and no information on other perinatal mental disorders, such as eating disorders and puerperal psychosis, was available. The variation of the quality of the included studies also limits the results, highlighting the need for high-quality data to suggest how maternity and mental health services could address domestic violence and improve health outcomes for women and their infants in the future. Nevertheless, this study emphasizes the importance of identifying and responding to possible domestic violence among women attending antenatal and mental health services.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001452.
The World Health Organization provides information and statistics about violence against women and also about mental health disorders during pregnancy
The UK Royal College of Psychiatrists has information for professionals and patients about mental health disorders during pregnancy
doi:10.1371/journal.pmed.1001452
PMCID: PMC3665851  PMID: 23723741
8.  Experiences of Domestic Violence and Mental Disorders: A Systematic Review and Meta-Analysis 
PLoS ONE  2012;7(12):e51740.
Background
Little is known about the extent to which being a victim of domestic violence is associated with different mental disorders in men and women. We aimed to estimate the prevalence and odds of being a victim of domestic violence by diagnostic category and sex.
Methods
Study design: Systematic review and meta-analysis. Data Sources: Eighteen biomedical and social sciences databases (including MEDLINE, EMBASE, PsycINFO); journal hand searches; scrutiny of references and citation tracking of included articles; expert recommendations, and an update of a systematic review on victimisation and mental disorder. Inclusion criteria: observational and intervention studies reporting prevalence or odds of being a victim of domestic violence in men and women (aged ≥16 years), using validated diagnostic measures of mental disorder. Procedure: Data were extracted and study quality independently appraised by two reviewers. Analysis: Random effects meta-analyses were used to pool estimates of prevalence and odds.
Results
Forty-one studies were included. There is a higher risk of experiencing adult lifetime partner violence among women with depressive disorders (OR 2.77 (95% CI 1.96–3.92), anxiety disorders (OR 4.08 (95% CI 2.39–6.97), and PTSD (OR 7.34 95% CI 4.50–11.98), compared to women without mental disorders. Insufficient data were available to calculate pooled odds for other mental disorders, family violence (i.e. violence perpetrated by a non-partner), or violence experienced by men. Individual studies reported increased odds for women and men for all diagnostic categories, including psychoses, with a higher prevalence reported for women. Few longitudinal studies were found so the direction of causality could not be investigated.
Conclusions
There is a high prevalence and increased likelihood of being a victim of domestic violence in men and women across all diagnostic categories, compared to people without disorders. Longitudinal studies are needed to identify pathways to being a victim of domestic violence to optimise healthcare responses.
doi:10.1371/journal.pone.0051740
PMCID: PMC3530507  PMID: 23300562
9.  Impact of Asthma on Educational Attainment in a Socioeconomically Deprived Population: A Study Linking Health, Education and Social Care Datasets 
PLoS ONE  2012;7(11):e43977.
Background
Asthma has the potential to adversely affect children's school examination performance, and hence longer term life chances. Asthma morbidity is especially high amongst UK ethnic minority children and those experiencing social adversity, populations which also have poor educational outcomes. We tested the hypothesis that asthma adversely affects performance in national school examinations in a large cohort from an area of ethnic diversity and social deprivation.
Methods and Findings
With a novel method (using patient and address-matching algorithms) we linked administrative and clinical data for 2002–2005 for children in east London aged 5–14 years to contemporaneous education and social care datasets. We modelled children's performance in school examinations in relation to socio-demographic and clinical variables.
The dataset captured examination performance for 12,136 children who sat at least one national examination at Key Stages 1–3. For illustration, estimates are presented as percentage changes in Key Stage 2 results. Having asthma was associated with a 1.1% increase in examination scores (95%CI 0.4 to 1.7)%,p = 0.02. Worse scores were associated with Bangladeshi ethnicity −1.3%(−2.5 to −0.1)%,p = 0.03; special educational need −14.6%(−15.7 to −13.5)%,p = 0.02; mental health problems −2.5%(−4.1 to −0.9)%,p = 0.003, and social adversity: living in a smoking household −1.2(−1.7 to −0.6)%,p<0.001; living in social housing −0.8%(−1.3 to −0.2)% p = 0.01, and entitlement to free school meals −0.8%(−1.5 to −0.1)%,p<0.001.
Conclusions
Social adversity and ethnicity, but not asthma, are associated with poorer performance in national school examinations. Policies to improve educational attainment in socially deprived areas should focus on these factors.
doi:10.1371/journal.pone.0043977
PMCID: PMC3498297  PMID: 23155367
10.  Responding to Domestic Violence in General Practice: A Qualitative Study on Perceptions and Experiences 
The perceptions and experiences among general practitioners (GPs) and nurses in identifying female patients experiencing domestic violence and referring patients to specialist agencies need to be clarified. Eleven GPs and six nurses participating in a multidisciplinary domestic violence training and support programme in east London and Bristol were interviewed. All participants recognised that identification of women experiencing domestic violence and offering support were part of their clinical roles. Perceived differences between GPs and nurses, including time constraints, level of patient interaction, awareness of patients' social history, scope of clinical interview, and patient expectations were used to explain their levels of domestic violence inquiry. Barriers to inquiry included lack of time, experience, awareness of community resources, and availability of effective interventions postdisclosure. Longstanding relationships with patients were cited both as barrier and facilitator to domestic violence disclosure. Some nurses reported discomfort with direct inquiry due to the lack of clinical experience in responding to domestic violence despite satisfaction with training. Future domestic violence training programmes should take into account potential differences between GPs and nurses, in terms of their clinical roles and the unique barriers encountered, in order to improve self-efficacy and to facilitate collaborative and effective responses.
doi:10.1155/2012/960523
PMCID: PMC3502852  PMID: 23259062
11.  Cost-effectiveness of Identification and Referral to Improve Safety (IRIS), a domestic violence training and support programme for primary care: a modelling study based on a randomised controlled trial 
BMJ Open  2012;2(3):e001008.
Objective
The Identification and Referral to Improve Safety (IRIS) cluster randomised controlled trial tested the effectiveness of a training and support intervention to improve the response of primary care to women experiencing domestic violence (DV). The aim of this study is to estimate the cost-effectiveness of this intervention.
Design
Markov model-based cost-effectiveness analysis.
Setting
General practices in two urban areas in the UK.
Participants
Simulated female individuals from the general UK population who were registered at general practices, aged 16 years and older.
Intervention
General practices received staff training, prompts to ask women about DV embedded in the electronic medical record, a care pathway including referral to a specialist DV agency and continuing contact from that agency. The trial compared the rate of referrals of women with specialist DV agencies from 24 general practices that received the IRIS programme with 24 general practices not receiving the programme. The trial did not measure outcomes for women beyond the intermediate outcome of referral to specialist agencies. The Markov model extrapolated the trial results to estimate the long-term healthcare and societal costs and benefits using data from other trials and epidemiological studies.
Results
The intervention would produce societal cost savings per woman registered in the general practice of UK£37 (95% CI £178 saved to a cost of £136) over 1 year. The incremental quality-adjusted life-year was estimated to be 0.0010 (95% CI −0.0157 to 0.0101) per woman. Probabilistic sensitivity analysis found 78% of model replications under a willingness to pay threshold of £20 000 per quality-adjusted life-year.
Conclusions
The IRIS programme is likely to be cost-effective and possibly cost saving from a societal perspective. Better data on the trajectory of abuse and the effect of advocacy are needed for a more robust model.
Trial registration
Current Controlled Trials, ISRCTN74012786.
Article summary
Article focus
The aim of this study was to assess the cost-effectiveness of the IRIS training and support intervention for primary care clinicians from the UK societal and NHS perspectives.
Key messages
The intervention is likely to be cost saving from a societal perspective with a high likelihood of being under a £20 000 per quality-adjusted life-year willingness to pay threshold.
Strengths and limitations of this study
We have minimised bias in estimating the effect size of the IRIS programme by basing it on a randomised controlled trial.
By using epidemiological and cost data external to the trial, we were able to extrapolate from directly measured trial outcomes (DV disclosure and referral rates) to quality of life, health and economic outcomes.
The uncertainty of the transition probabilities based on assumptions was addressed by probabilistic sensitivity analysis, contributing to the robustness of the model.
Important limitations of that data are the paucity of longitudinal studies measuring the trajectory of abuse and uncertainty about the effect of DV advocacy for women not living in a refuge or shelter.
doi:10.1136/bmjopen-2012-001008
PMCID: PMC3383977  PMID: 22730555
12.  Is access to specialist assessment of chest pain equitable by age, gender, ethnicity and socioeconomic status? An enhanced ecological analysis 
BMJ Open  2012;2(3):e001025.
Objectives
To determine whether access to rapid access chest pain clinics of people with recent onset symptoms is equitable by age, socioeconomic status, ethnicity and gender, according to need.
Design
Retrospective cohort study with ecological analysis.
Setting
Patients referred from primary care to five rapid access chest pain clinics in secondary care, across England.
Participants
Of 8647 patients aged ≥35 years referred to chest pain clinics with new-onset stable chest pain but no known cardiac history, 7570 with documented census ward codes, age, gender and ethnicity comprised the study group. Patients excluded were those with missing date of birth, gender or ethnicity (n=782) and those with missing census ward codes (n=295).
Outcome measures
Effects of age, gender, ethnicity and socioeconomic status on clinic attendance were calculated as attendance rate ratios, with number of attendances as the outcome and resident population-years as the exposure in each stratum, using Poisson regression. Attendance rate ratios were then compared with coronary heart disease (CHD) mortality ratios to determine whether attendance was equitable according to need.
Results
Adjusted attendance rate ratios for patients aged >65 years were similar to younger patients (1.1, 95% CI 1.05 to 1.16), despite population CHD mortality rate ratios nearly 15 times higher in the older age group. Women had lower attendance rate ratios (0.81, 95% CI 0.77 to 0.84) and also lower population CHD mortality rate ratios compared with men. South Asians had higher attendance rates (1.67, 95% CI 1.57 to 1.77) compared with whites and had a higher standardised CHD mortality ratio of 1.46 (95% CI 1.41 to 1.51). Although univariable analysis showed that the most deprived patients (quintile 5) had an attendance rate twice that of less deprived quintiles, the adjusted analysis showed their attendance to be 13% lower (0.87, 95% CI 0.81 to 0.94) despite a higher population CHD mortality rate.
Conclusion
There is evidence of underutilisation of chest pain clinics by older people and those from lower socioeconomic status. More robust and patient focused administrative pathways need to be developed to detect inequity, correction of which has the potential to substantially reduce coronary mortality.
Article summary
Article focus
Is access to chest pain clinics of people with recent onset symptoms equitable according to local need and consistent with national policy.
Key messages
Need for evaluation in chest pain clinics will vary according to the variable incidence of heart disease in different age, gender, socioeconomic and ethnic groups.
There is evidence of underutilisation of chest pain clinics by older people and those from lower socioeconomic status.
Strengths and limitations of this study
Large, diverse and unselected patient population with uniformly collected patient-level data, allowing robust comparisons between demographic and clinical groups.
Ecological fallacy with respect to age and sex has been avoided by applying an enhanced ecological analysis.
Need to use census wards, not postcodes, as the smallest geographical areas for which mortality and demographic data were available.
Ethnicity was not based on self-ascription.
doi:10.1136/bmjopen-2012-001025
PMCID: PMC3378943  PMID: 22700834
13.  Treading carefully: a qualitative ethnographic study of the clinical, social and educational uses of exercise ECG in evaluating stable chest pain 
BMJ Open  2012;2(1):e000508.
Objective
To examine functions of the exercise ECG in the light of the recent National Institute for Health and Clinical Excellence guidelines recommending that it should not be used for the diagnosis or exclusion of stable angina.
Design
Qualitative ethnographic study based on interviews and observations of clinical practice.
Setting
3 rapid access chest pain clinics in England.
Participants
Observation of 89 consultations in chest pain clinics, 18 patient interviews and 12 clinician interviews.
Main outcome measure
Accounts and observations of consultations in chest pain clinics.
Results
The exercise ECG was observed to have functions that extended beyond diagnosis. It was used to clarify a patient's story and revise the initial account. The act of walking on the treadmill created an additional opportunity for dialogue between clinician and patient and engagement of the patient in the diagnostic process through precipitation of symptoms and further elaboration of symptoms. The exercise ECG facilitated reassurance in relation to exercise capacity and tolerance, providing a platform for behavioural advice particularly when exercise was promoted by the clinician.
Conclusions
Many of the practices that have been built up around the use of the exercise ECG are potentially beneficial to patients and need to be considered in the re-design of services without that test. Through its contribution to the patient's history and to subsequent advice to the patient, the exercise ECG continues to inform the specialist assessment and management of patients with new onset stable chest pain, beyond its now marginalised role in diagnosis.
Article summary
Article focus
Given the widespread use of the exercise ECG in assessments of patients with stable chest pain, this paper seeks to understand its role in the light of emerging evidence about its poor performance as a diagnostic test.
This paper reports on the functions of the exercise ECG in UK chest pain clinics, highlighting those uses that go beyond its diagnostic function.
This paper is part of an international debate about the appropriate initial tests for patients with new onset stable chest pain.
Key messages
The exercise ECG has additional functions that transcend its technical contribution to diagnosis: it can help clarify symptoms and other aspects of the clinical history, engage the patient in the diagnostic process, provide a context for guidance on reversible cardiovascular risk factors, be used to better involve and reassure patients and has the potential use for tailored lifestyle advice.
Through its contribution to the patient's history and to subsequent advice to the patient, the exercise ECG continues to inform the specialist assessment and management of patients with new onset stable chest pain, beyond its now marginalised role in diagnosis.
Many of the practices that have been built up around the use of the exercise ECG are potentially beneficial to patients. As chest pain clinic services are re-configured without the test, in line with UK national (National Institute for Health and Clinical Excellence (NICE)) guidance, these practices need to be integrated into new diagnostic pathways.
Strengths and limitations of this study
A strength of our study is its ethnographic design incorporating the observation of patient–clinician consultations and combining these data with interviews: we knew what participants did as well as said.
The fieldwork was undertaken at a key time just before the introduction of the UK's 2010 NICE guidelines and therefore provides an understanding of current practice that can inform their implementation.
A limitation of our study is that data were collected largely from two chest pain clinics, potentially limiting the transferability of the findings, although the clinicians in the research team thought that the clinics were not atypical compared to others they had experienced.
doi:10.1136/bmjopen-2011-000508
PMCID: PMC3277903  PMID: 22318662
14.  Development of the AGREE II, part 1: performance, usefulness and areas for improvement 
Background
We undertook research to improve the AGREE instrument, a tool used to evaluate guidelines. We tested a new seven-point scale, evaluated the usefulness of the original items in the instrument, investigated evidence to support shorter, tailored versions of the tool, and identified areas for improvement.
Method
We report on one component of a larger study that used a mixed design with four factors (user type, clinical topic, guideline and condition). For the analysis reported in this article, we asked participants to read a guideline and use the AGREE items to evaluate it based on a seven-point scale, to complete three outcome measures related to adoption of the guideline, and to provide feedback on the instrument’s usefulness and how to improve it.
Results
Guideline developers gave lower-quality ratings than did clinicians or policy-makers. Five of six domains were significant predictors of participants’ outcome measures (p < 0.05). All domains and items were rated as useful by stakeholders (mean scores > 4.0) with no significant differences by user type (p > 0.05). Internal consistency ranged between 0.64 and 0.89. Inter-rater reliability was satisfactory. We received feedback on how to improve the instrument.
Interpretation
Quality ratings of the AGREE domains were significant predictors of outcome measures associated with guideline adoption: guideline endorsements, overall intentions to use guidelines, and overall quality of guidelines. All AGREE items were assessed as useful in determining whether a participant would use a guideline. No clusters of items were found more useful by some users than others. The measurement properties of the seven-point scale were promising. These data contributed to the refinements and release of the AGREE II.
doi:10.1503/cmaj.091714
PMCID: PMC2900328  PMID: 20513780
15.  Development of the AGREE II, part 2: assessment of validity of items and tools to support application 
Background
We established a program of research to improve the development, reporting and evaluation of practice guidelines. We assessed the construct validity of the items and user’s manual in the β version of the AGREE II.
Methods
We designed guideline excerpts reflecting high-and low-quality guideline content for 21 of the 23 items in the tool. We designed two study packages so that one low-quality and one high-quality version of each item were randomly assigned to each package. We randomly assigned 30 participants to one of the two packages. Participants reviewed and rated the guideline content according to the instructions of the user’s manual and completed a survey assessing the manual.
Results
In all cases, content designed to be of high quality was rated higher than low-quality content; in 18 of 21 cases, the differences were significant (p < 0.05). The manual was rated by participants as appropriate, easy to use, and helpful in differentiating guidelines of varying quality, with all scores above the mid-point of the seven-point scale. Considerable feedback was offered on how the items and manual of the β-AGREE II could be improved.
Interpretation
The validity of the items was established and the user’s manual was rated as highly useful by users. We used these results and those of our study presented in part 1 to modify the items and user’s manual. We recommend AGREE II (available at www.agreetrust.org) as the revised standard for guideline development, reporting and evaluation.
doi:10.1503/cmaj.091716
PMCID: PMC2900368  PMID: 20513779
16.  Prognosis of stable angina pectoris: why we need larger population studies with higher endpoint resolution 
Heart  2006;93(7):786-791.
The prognosis of angina was described as “"unhappy” by the Framingham investigators and as little different from that of 1‐year survivors of acute myocardial infarction. Yet recent clinical trials now report that angina has a good prognosis with adverse outcomes reduced to “normal levels”. These disparate prognostic assessments may not be incompatible, applying as they do to population cohorts (Framingham) and selected participants in clinical trials. Comparisons between studies are further complicated by the absence of agreed case definitions for stable angina (contrast this with acute coronary syndromes). Our recent data show that for patients with recent onset symptoms attending chest pain clinics, angina remains a high‐risk diagnosis and although many patients receive symptomatic benefit from revascularisation, prognosis is usually unaffected. This leaves little room for complacency and, with angina the commonest initial manifestation of coronary artery disease, there is the opportunity for early detection, risk stratification and treatment to modify outcomes. Meanwhile, larger population‐based studies are needed to define the patient journey from earliest presentation through the various syndrome transitions to coronary or noncardiac death in order to increase understanding of the aetiological and prognostic differences between the different coronary disease phenotypes.
doi:10.1136/hrt.2006.103119
PMCID: PMC1994448  PMID: 16952966
17.  Cardiothoracic ratio within the “normal” range independently predicts mortality in patients undergoing coronary angiography 
Heart  2006;93(4):491-494.
Objective
To determine whether cardiothoracic ratio (CTR), within the range conventionally considered normal, predicted prognosis in patients undergoing coronary angiography.
Design
Cohort study with a median of 7‐years follow‐up.
Setting
Consecutive patients undergoing coronary angiography at Barts and The London National Health Service (NHS) Trust.
Subjects
1005 patients with CTRs measured by chest radiography, and who subsequently underwent coronary angiography. Of these patients, 7.3% had a CTR ⩾0.5 and were excluded from the analyses.
Outcomes
All‐cause mortality and coronary event (non‐fatal myocardial infarction or coronary death). Adjustments were made for age, left ventricular dysfunction, ACE inhibitor treatment, body mass index, number of diseased coronary vessels and past coronary artery bypass graft.
Results
The risk of death was increased among patients with a CTR in the upper part of the normal range. In total, 94 (18.9%) of those with a CTR below the median of 0.42 died compared with 120 (27.8%) of those with a CTR between 0.42 and 0.49 (log rank test p<0.001). After adjusting for potential confounders, this increased risk remained (adjusted HR 1.45, 95% CI 1.03 to 2.05). CTR, at values below 0.5, was linearly related to the risk of coronary event (test for trend p = 0.024).
Conclusion
: In patients undergoing coronary angiography, CTR between 0.42 and 0.49 was associated with higher mortality than in patients with smaller hearts. There was evidence of a continuous increase in risk with higher CTR. These findings, along with those in healthy populations, question the conventional textbook cut‐off point of ⩾0.5 being an abnormal CTR.
doi:10.1136/hrt.2006.101238
PMCID: PMC1861494  PMID: 17164481
18.  Primary care Identification and Referral to Improve Safety of women experiencing domestic violence (IRIS): protocol for a pragmatic cluster randomised controlled trial 
BMC Public Health  2010;10:54.
Background
Domestic violence, which may be psychological, physical, sexual, financial or emotional, is a major public health problem due to the long-term health consequences for women who have experienced it and for their children who witness it. In populations of women attending general practice, the prevalence of physical or sexual abuse in the past year from a partner or ex-partner ranges from 6 to 23%, and lifetime prevalence from 21 to 55%. Domestic violence is particularly important in general practice because women have many contacts with primary care clinicians and because women experiencing abuse identify doctors and nurses as professionals from whom they would like to get support. Yet health professionals rarely ask about domestic violence and have little or no training in how to respond to disclosure of abuse.
Methods/Design
This protocol describes IRIS, a pragmatic cluster randomised controlled trial with the general practice as unit of randomisation. Our trial tests the effectiveness and cost-effectiveness of a training and support programme targeted at general practice teams. The primary outcome is referral of women to specialist domestic violence agencies. Forty-eight practices in two UK cities (Bristol and London) are randomly allocated, using minimisation, into intervention and control groups. The intervention, based on an adult learning model in an educational outreach framework, has been designed to address barriers to asking women about domestic violence and to encourage appropriate responses to disclosure and referral to specialist domestic violence agencies. Multidisciplinary training sessions are held with clinicians and administrative staff in each of the intervention practices, with periodic feedback of identification and referral data to practice teams. Intervention practices have a prompt to ask about abuse integrated in the electronic medical record system. Other components of the intervention include an IRIS champion in each practice and a direct referral pathway to a named domestic violence advocate.
Discussion
This is the first European randomised controlled trial of an intervention to improve the health care response to domestic violence. The findings will have the potential to inform training and service provision.
Trial registration
ISRCTN74012786
doi:10.1186/1471-2458-10-54
PMCID: PMC2825222  PMID: 20122266
19.  Assessing the cost effectiveness of using prognostic biomarkers with decision models: case study in prioritising patients waiting for coronary artery surgery 
Objective To determine the effectiveness and cost effectiveness of using information from circulating biomarkers to inform the prioritisation process of patients with stable angina awaiting coronary artery bypass graft surgery.
Design Decision analytical model comparing four prioritisation strategies without biomarkers (no formal prioritisation, two urgency scores, and a risk score) and three strategies based on a risk score using biomarkers: a routinely assessed biomarker (estimated glomerular filtration rate), a novel biomarker (C reactive protein), or both. The order in which to perform coronary artery bypass grafting in a cohort of patients was determined by each prioritisation strategy, and mean lifetime costs and quality adjusted life years (QALYs) were compared.
Data sources Swedish Coronary Angiography and Angioplasty Registry (9935 patients with stable angina awaiting coronary artery bypass grafting and then followed up for cardiovascular events after the procedure for 3.8 years), and meta-analyses of prognostic effects (relative risks) of biomarkers.
Results The observed risk of cardiovascular events while on the waiting list for coronary artery bypass grafting was 3 per 10 000 patients per day within the first 90 days (184 events in 9935 patients). Using a cost effectiveness threshold of £20 000-£30 000 (€22 000-€33 000; $32 000-$48 000) per additional QALY, a prioritisation strategy using a risk score with estimated glomerular filtration rate was the most cost effective strategy (cost per additional QALY was <£410 compared with the Ontario urgency score). The impact on population health of implementing this strategy was 800 QALYs per 100 000 patients at an additional cost of £245 000 to the National Health Service. The prioritisation strategy using a risk score with C reactive protein was associated with lower QALYs and higher costs compared with a risk score using estimated glomerular filtration rate.
Conclusion Evaluating the cost effectiveness of prognostic biomarkers is important even when effects at an individual level are small. Formal prioritisation of patients awaiting coronary artery bypass grafting using a routinely assessed biomarker (estimated glomerular filtration rate) along with simple, routinely collected clinical information was cost effective. Prioritisation strategies based on the prognostic information conferred by C reactive protein, which is not currently measured in this context, or a combination of C reactive protein and estimated glomerular filtration rate, is unlikely to be cost effective. The widespread practice of using only implicit or informal means of clinically ordering the waiting list may be harmful and should be replaced with formal prioritisation approaches.
doi:10.1136/bmj.b5606
PMCID: PMC2808469  PMID: 20085988
20.  Women's evaluation of abuse and violence care in general practice: a cluster randomised controlled trial (weave) 
BMC Public Health  2010;10:2.
Background
Intimate partner abuse (IPA) is a major public health problem with serious implications for the physical and psychosocial wellbeing of women, particularly women of child-bearing age. It is a common, hidden problem in general practice and has been under-researched in this setting. Opportunities for early intervention and support in primary care need to be investigated given the frequency of contact women have with general practice. Despite the high prevalence and health consequences of abuse, there is insufficient evidence for screening in primary care settings. Furthermore, there is little rigorous evidence to guide general practitioners (GPs) in responding to women identified as experiencing partner abuse. This paper describes the design of a trial of a general practice-based intervention consisting of screening for fear of partner with feedback to GPs, training for GPs, brief counselling for women and minimal practice organisational change. It examines the effect on women's quality of life, mental health and safety behaviours.
Methods/Design
weave is a cluster randomised controlled trial involving 40 general practices in Victoria, Australia. Approximately 500 women (16-50 years) seen by the GP in the previous year are mailed a short lifestyle survey containing an item to screen for IPA. Women who indicate that they were afraid of a partner/ex-partner in the last year and provide contact details are invited to participate. Once baseline data are collected, GPs are randomly assigned to either a group involving healthy relationship and responding to IPA training plus inviting women for up to 6 sessions of counselling or to a group involving basic education and usual care for women. Outcomes will be evaluated by postal survey at 6 and 12 months following delivery of the intervention. There will be an economic evaluation, and process evaluation involving interviews with women and GPs, to inform understanding about implementation and outcomes.
Discussion
The weave trial responds to an urgent need for more evidence on what can be achieved in primary care with regard to responding to women who experience IPA. It will provide important knowledge about the effectiveness of a brief method of screening, professional IPA training program and brief counselling for women.
Trail Registration
[ACTRN12608000032358]
doi:10.1186/1471-2458-10-2
PMCID: PMC2823699  PMID: 20044929
21.  Reliability and validity of a new scale on internal coherence (ICS) of cancer patients 
Background
Current inventories on quality of life used in oncology mainly focus on functional aspects of patients in the context of disease adaption and treatments (side) effects (EORTC QLQ C30) or generically the status of common functions (Medical Outcome Study SF 36). Beyond circumscribed dimensions of quality of life (i.e., physical, emotional, social, cognitive etc.), there is a lack of inventories which also address other relevant dimensions such as the 'sense of coherence' (SOC) in cancer patients. SOC is important because of its potential prognostic relevance in cancer patients, but the current SOC scale has mainly been validated for psychiatric and psychosomatic patients. Our two-step validation study addresses the internal coherence (ICS) scale, which is based on expert rating, using specific items for oncological patients, with respect to its reliability, validity and sensitivity to chemotherapy.
Methods
The items were tested on 114 participants (57 cancer patients and a matched control group), alongside questions on autonomic regulation (aR), the Hospital Anxiety and Depression Scale (HADS), self-regulation (SRQ) and Karnofsky the Performance-Index (KPI). A retest of 65 participants was carried out after a median time span of four weeks.
In the second part of the study, the ICS was used to assess internal coherence during chemotherapy in 25 patients with colorectal carcinoma (CRC) and 17 breast cancer patients. ICS was recorded before, during and 4 – 8 weeks after treatment.
Results
The 10-item scale of 'internal coherence' (ICS) shows good to very good reliability: Cronbach-α r = 0.91, retest-reliability r = 0.80. The ICS correlates with r = 0.43 – 0.72 to the convergence criteria (all p < 0.001). We are able to show decreased ICS-values after the third cycle for CRC and breast cancer patients, with a subsequent increase of ICS scores after the end of chemotherapy.
Conclusion
The ICS has good to very good reliability, validity and sensitivity to chemotherapy.
doi:10.1186/1477-7525-7-59
PMCID: PMC2712459  PMID: 19552807
22.  Incremental prognostic value of the exercise electrocardiogram in the initial assessment of patients with suspected angina: cohort study 
Objective To determine whether resting and exercise electrocardiograms (ECGs) provide prognostic value that is incremental to that obtained from the clinical history in ambulatory patients with suspected angina attending chest pain clinics.
Design Multicentre cohort study.
Setting Rapid access chest pain clinics of six hospitals in England.
Participants 8176 consecutive patients with suspected angina and no previous diagnosis of coronary artery disease, all of whom had a resting ECG recorded. 4848 patients with a summary exercise ECG result recorded (positive, negative, equivocal for ischaemia) comprised the summary ECG subset of whom 1422 with more detailed exercise ECG data recorded comprised the detailed ECG subset.
Main outcome measure Composite of death due to coronary heart disease or non-fatal acute coronary syndrome during median follow-up of 2.46 years.
Results Receiver operating characteristics curves for the basic clinical assessment model alone and with the results of resting ECGs were superimposed with little difference in the C statistic. With the exercise ECGs the C statistic in the summary ECG subset increased from 0.70 (95% confidence interval 0.68 to 0.73) to 0.74 (0.71 to 0.76) and in the detailed ECG subset from 0.74 (0.70 to 0.79) to 0.78 (0.74 to 0.82). However, risk stratified cumulative probabilities of the primary end point at one year and six years for all three prognostic indices (clinical assessment only; clinical assessment plus resting ECG; clinical assessment plus resting ECG plus exercise ECG) showed only small differences at all time points and at all levels of risk.
Conclusion In ambulatory patients with suspected angina, basic clinical assessment encompasses nearly all the prognostic value of resting ECGs and most of the prognostic value of exercise ECGs. The limited incremental value of these widely applied tests emphasises the need for more effective methods of risk stratification in this group of patients.
doi:10.1136/bmj.a2240
PMCID: PMC2583389  PMID: 19008264
23.  Presentation of stable angina pectoris among women and South Asian people 
Background
There is speculation that women and South Asian people are more likely than men and white people to report atypical angina and that they are less likely to undergo invasive management of angina. We sought to determine whether atypical symptoms of angina pectoris in women and South Asians impacted clinically important outcomes and clinical management.
Methods
We prospectively identified 2189 South Asian people and 5605 white people with recent-onset chest pain at 6 chest-pain clinics in the United Kingdom. We documented hospital admissions for acute coronary syndromes, coronary deaths as well as coronary angiography and revascularization procedures.
Results
Atypical chest pain was reported by more women than men (56.5% vs 54.5%, p < 0.054) and by more South Asian patients than white patients (59.9% vs 52.5%, p < 0.001). Typical symptoms were associated with coronary death or acute coronary syndromes among women (hazard ratio [HR] 2.30, 95% CI 1.70–3.11, p < 0.001) but not among men (HR 1.23, 95% CI 0.96–1.57, p = 0.10). Typical symptoms were associated with coronary outcomes in both South Asian and white patients. Among those with typical symptoms, women (HR 0.76, 95% CI 0.63–0.92, p = 0.004) and South Asian patients (HR 0.52, 95% CI 0.41–0.67, p < 0.001) were less likely than men and white patients to receive angiography.
Interpretation
Compared to those with atypical chest pain, women and South Asian patients with typical pain had worse clinical outcomes. However, sex and ethnic background did not explain differences in the use of invasive procedures.
doi:10.1503/cmaj.071763
PMCID: PMC2535745  PMID: 18809897
24.  Inequity of access to investigation and effect on clinical outcomes: prognostic study of coronary angiography for suspected stable angina pectoris 
BMJ : British Medical Journal  2008;336(7652):1058-1061.
Objectives To determine whether coronary angiography for suspected stable angina pectoris is underused in older patients, women, south Asian patients, and those from socioeconomically deprived areas, and, if it is, whether this is associated with higher coronary event rates.
Design Multicentre cohort with five year follow-up.
Setting Six ambulatory care clinics in England.
Participants 1375 consecutive patients in whom coronary angiography was individually rated as appropriate with the Rand consensus method.
Main outcome measures Receipt of angiography (420 procedures); coronary mortality and acute coronary syndrome events.
Results In a multivariable analysis, angiography was less likely to be performed in patients aged over 64 compared with those aged under 50 (hazard ratio 0.60, 95% confidence interval 0.38 to 0.96), women compared with men (0.42, 0.35 to 0.50), south Asians compared with white people (0.48, 0.34 to 0.67), and patients in the most deprived fifth compared with the other four fifths (0.66, 0.40 to 1.08). Not undergoing angiography when it was deemed appropriate was associated with higher rates of coronary event.
Conclusions At an early stage after presentation with suspected angina, coronary angiography is underused in older people, women, south Asians, and people from deprived areas. Not receiving appropriate angiography was associated with a higher risk of coronary events in all groups. Interventions based on clinical guidance that supports individualised management decisions might improve access and outcomes.
doi:10.1136/bmj.39534.571042.BE
PMCID: PMC2376033  PMID: 18436918
25.  Internal and external validity of cluster randomised trials: systematic review of recent trials 
BMJ : British Medical Journal  2008;336(7649):876-880.
Objectives To assess aspects of the internal validity of recently published cluster randomised trials and explore the reporting of information useful in assessing the external validity of these trials.
Design Review of 34 cluster randomised trials in primary care published in 2004 and 2005 in seven journals (British Medical Journal, British Journal of General Practice, Family Practice, Preventive Medicine, Annals of Internal Medicine, Journal of General Internal Medicine, Pediatrics).
Data sources National Library of Medicine (Medline) via PubMed.
Data extraction To assess aspects of internal validity we extracted data on appropriateness of sample size calculations and analyses, methods of identifying and recruiting individual participants, and blinding. To explore reporting of information useful in assessing external validity we extracted data on cluster eligibility, cluster inclusion and retention, cluster generalisability, and the feasibility and acceptability of the intervention to health providers in clusters.
Results 21 (62%) trials accounted for clustering in sample size calculations and 30 (88%) in the analysis; about a quarter were potentially biased because of procedures surrounding recruitment and identification of patients; individual participants were blind to allocation status in 19 (56%) and outcome assessors were blind in 15 (44%). In almost half the reports, information relating to generalisability of clusters was poorly reported, and in two fifths there was no information about the feasibility and acceptability of the intervention.
Conclusions Cluster randomised trials are essential for evaluating certain types of interventions. Issues affecting their internal validity, such as appropriate sample size calculations and analysis, have been widely disseminated and are now better addressed by researchers. Blinding of those identifying and recruiting patients to allocation status is recommended but is not always carried out. There may be fewer barriers to internal validity in trials in which individual participants are not recruited. External validity seems poorly addressed in many trials, yet is arguably as important as internal validity in judging quality as a basis for healthcare intervention.
doi:10.1136/bmj.39517.495764.25
PMCID: PMC2323095  PMID: 18364360

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