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1.  Attentional bias retraining in cigarette smokers attempting smoking cessation (ARTS): Study protocol for a double blind randomised controlled trial 
BMC Public Health  2013;13:1176.
Background
Smokers attend preferentially to cigarettes and other smoking-related cues in the environment, in what is known as an attentional bias. There is evidence that attentional bias may contribute to craving and failure to stop smoking. Attentional retraining procedures have been used in laboratory studies to train smokers to reduce attentional bias, although these procedures have not been applied in smoking cessation programmes. This trial will examine the efficacy of multiple sessions of attentional retraining on attentional bias, craving, and abstinence in smokers attempting cessation.
Methods/Design
This is a double-blind randomised controlled trial. Adult smokers attending a 7-session weekly stop smoking clinic will be randomised to either a modified visual probe task with attentional retraining or placebo training. Training will start 1 week prior to quit day and be given weekly for 5 sessions. Both groups will receive 21 mg transdermal nicotine patches for 8–12 weeks and withdrawal-orientated behavioural support for 7 sessions. Primary outcome measures are the change in attentional bias reaction time and urge to smoke on the Mood and Physical Symptoms Scale at 4 weeks post-quit. Secondary outcome measures include differences in withdrawal, time to first lapse and prolonged abstinence at 4 weeks post-quit, which will be biochemically validated at each clinic visit. Follow-up will take place at 8 weeks, 3 months and 6 months post-quit.
Discussion
This is the first randomised controlled trial of attentional retraining in smokers attempting cessation. This trial could provide proof of principle for a treatment aimed at a fundamental cause of addiction.
Trial registration
Current Controlled Trials: ISRCTN54375405.
doi:10.1186/1471-2458-13-1176
PMCID: PMC3890623  PMID: 24330656
2.  Predictors of change in objectively measured and self-reported health behaviours among individuals with recently diagnosed type 2 diabetes: longitudinal results from the ADDITION-Plus trial cohort 
Background
There is limited evidence about predictors of health behaviour change in people with type 2 diabetes. The aim of this study was to assess change in health behaviours over one year and to identify predictors of behaviour change among adults with screen-detected and recently clinically diagnosed diabetes.
Methods
ADDITION-Plus was a randomised controlled trial of a behaviour change intervention among 478 patients (40–69 years). Physical activity and diet were measured objectively (physical activity at 1 year) and by self-report at baseline and one year. Associations between baseline predictors and behaviour change were quantified using multivariable linear regression.
Results
Participants increased their plasma vitamin C and fruit intake, reduced energy and fat intake from baseline to follow-up. Younger age, male sex, a smaller waist circumference, and a lower systolic blood pressure at baseline were associated with higher levels of objectively measured physical activity at one year. Greater increases in plasma vitamin C were observed in women (beta-coefficient [95% CI]: beta = −5.52 [−9.81, -1.22]) and in those with screen-detected diabetes (beta = 6.09 [1.74, 10.43]). Younger age predicted a greater reduction in fat (beta = −0.43 [−0.72, -0.13]) and energy intake (beta = −6.62 [−13.2, -0.05]). Patients with screen-detected diabetes (beta = 74.2 [27.92, 120.41]) reported a greater increase in fruit intake. There were no significant predictors of change in self-reported physical activity. Beliefs about behaviour change and diabetes did not predict behaviour change.
Conclusions
Older patients, men and those with a longer duration of diabetes may need more intensive support for dietary change. We recommend that future studies use objective measurement of health behaviours and that researchers add predictors beyond the individual level. Our results support a focus on establishing healthy lifestyle changes early in the diabetes disease trajectory.
doi:10.1186/1479-5868-10-118
PMCID: PMC3874745  PMID: 24152757
Health behaviour; Behaviour change; Predictors; Type 2 diabetes; Newly diagnosed
3.  Impact of Personalised Feedback about Physical Activity on Change in Objectively Measured Physical Activity (the FAB Study): A Randomised Controlled Trial 
PLoS ONE  2013;8(9):e75398.
Background
Low levels of physical activity are a major public health concern, and interventions to promote physical activity have had limited success. Whether or not personalised feedback about physical activity following objective measurement motivates behaviour change has yet to be rigorously examined.
Methods
And Findings: In a parallel group, open randomised controlled trial, 466 healthy adults aged 32 to 54 years were recruited from the ongoing population-based Fenland Study (Cambridgeshire, UK). Participants were randomised to receive either no feedback until the end of the trial (control group, n=120) or one of three different types of feedback: simple, visual, or contextualised (intervention groups, n=346). The primary outcome was physical activity (physical activity energy expenditure (PAEE) in kJ/kg/day and average body acceleration (ACC) in m/s2) measured objectively using a combined heart rate monitor and accelerometer (Actiheart®). The main secondary outcomes included self-reported physical activity, intention to increase physical activity, and awareness of physical activity (the agreement between self-rated and objectively measured physical activity). At 8 weeks, 391 (83.9%) participants had complete physical activity data. The intervention had no effect on objectively measured physical activity (PAEE: β=-0.92, 95% CI=-3.50 to 1.66, p=0.48 and ACC: β=0.01, 95% CI=-0.00 to 0.02, p=0.21), self-reported physical activity (β=-0.39, 95% CI=-1.59 to 0.81), or intention to increase physical activity (β=-0.05, 95% CI=-0.22 to 0.11). However, it was associated with an increase in awareness of physical activity (OR=1.74, 95% CI=1.05 to 2.89). Results did not differ according to the type of feedback.
Conclusions
Personalised feedback about physical activity following objective measurement increased awareness but did not result in changes in physical activity in the short term. Measurement and feedback may have a role in promoting behaviour change but are ineffective on their own.
Trial Registration
Current Controlled Trials ISRCTN92551397 http://www.controlled-trials.com/ISRCTN92551397
doi:10.1371/journal.pone.0075398
PMCID: PMC3774634  PMID: 24066178
4.  Socio-demographic and behavioural correlates of physical activity perception in individuals with recently diagnosed diabetes: results from a cross-sectional study 
BMC Public Health  2013;13:678.
Background
Physical activity (PA) levels in type 2 diabetes mellitus (T2DM) patients are generally low. Poor PA perception may impede healthy behaviour change in this high risk group. We describe (i) objective PA levels, (ii) the difference between objective and self-reported PA (‘PA disparity’) and the correlates of (iii) PA disparity and (iv) overestimation in recently diagnosed T2DM patients.
Methods
Cross-sectional analysis of 425 recently diagnosed T2DM patients aged 42 to 71, participating in the ADDITION-Plus study in Eastern England, UK. We define ‘PA disparity’ as the non-negative value of the difference (in mathematical terms the absolute difference) between objective and self-reported physical activity energy expenditure (PAEE in kJ · kg-1 · day-1). ‘Overestimators’ comprised those whose self-reported- exceeded objective-PAEE by 4.91 kJ · kg-1 · day-1(the equivalent of 30 minutes moderate activity per day). Multivariable linear regression examined the association between PA disparity (continuous) and socio-demographic, clinical, health behaviour, quality of life and psychological characteristics. Logistic regression examined the association between PA overestimation and individual characteristics.
Results
Mean objective and self-reported PAEE levels ± SD were 34.4 ± 17.0 and 22.6 ± 19.4 kJ · kg-1 · day-1, respectively (difference in means =11.8; 95% CI = 9.7 to 13.9 kJ · kg-1 · day-1). Higher PA disparity was associated with male sex, younger age, lower socio-economic status and lower BMI. PA overestimators comprised 19% (n = 80), with those in routine/manual occupations more likely to be overestimators than those in managerial/professional occupations.
Conclusions
T2DM patients with poor physical activity perception are more likely to be male, younger, from a lower socio-economic class and to have a lower BMI. PA overestimators were more likely to be in lower socio-economic categories. Self-monitoring and targeted feedback, particularly to those in lower socio-economic categories, may improve PA perceptions and optimise interventions in T2DM patients. Our findings suggest that strategies for enabling realistic assessment of physical activity levels, through self-monitoring or feedback, warrant further investigation and may help refine and improve physical activity interventions.
doi:10.1186/1471-2458-13-678
PMCID: PMC3729669  PMID: 23883169
Type 2 diabetes mellitus; Physical activity; Overestimation; Awareness; Perception; Health behaviour; Lifestyle behaviour; Social correlates of health; Health promotion intervention
5.  Evaluating the effectiveness of using personal tailored risk information and taster sessions to increase the uptake of smoking cessation services: study protocol for a randomised controlled trial 
Trials  2012;13:195.
Background
Although government-funded specialist smoking cessation services in England offer advice and support to smokers motivated to quit, only a small proportion of smokers make use of this service. Evidence suggests that if smokers are proactively and personally invited to use services, use will be higher than with a standard referral made by health professionals. Computer-based systems generating personalised tailored communications also have the potential to engage with a larger proportion of the smoking population. In this study smokers are proactively invited to use the NHS Stop Smoking Service (SSS), with a personal computer-tailored letter and the offer of a no-commitment introductory session designed to give more information about the service. The primary objective is to assess the relative effectiveness on attendance at the NHS SSS, of proactive recruitment by a brief personal letter, tailored to individual characteristics, and invitation to a taster session, over a standard generic letter advertising the service.
Method/design
This randomised controlled trial will recruit smokers from general practice who are motivated to quit and have not recently attended the NHS SSS. Smokers aged 16 years and over, identified from medical records in participating practices, are sent a brief screening questionnaire and cover letter from their GP. Smokers giving consent are randomised to the Control group to receive a standard generic letter advertising the local service, or to the Intervention group to receive a brief personal, tailored letter with risk information and an invitation to attend a ‘Come and Try it’ taster session. The primary outcome, assessed 6 months after the date of randomisation, is the proportion of people attending the NHS SSS for at least one session. Planned recruitment is to secure 4,500 participants, from 18 regions in England served by an NHS SSS.
Discussion
Personal risk information generated by computer, with the addition of taster sessions, could be widely replicated and delivered cost effectively to a large proportion of the smoking population. The results of this trial will inform the potential of this method to increase referrals to specialised smoking cessation services and prompt more quit attempts.
Trial registration
Current Controlled Trials ISRCTN76561916
doi:10.1186/1745-6215-13-195
PMCID: PMC3563550  PMID: 23078797
Smoking cessation; Stop smoking clinics; Computer-tailoring; Personalisation; Risk information
6.  An exploration of the missing data mechanism in an Internet based smoking cessation trial 
Background
Missing outcome data are very common in smoking cessation trials. It is often assumed that all such missing data are from participants who have been unsuccessful in giving up smoking (“missing=smoking”). Here we use data from a recent Internet based smoking cessation trial in order to investigate which of a set of a priori chosen baseline variables are predictive of missingness, and the evidence for and against the “missing=smoking” assumption.
Methods
We use a selection model, which models the probability that the outcome is observed given the outcome and other variables. The selection model includes a parameter for which zero indicates that the data are Missing at Random (MAR) and large values indicate “missing=smoking”. We examine the evidence for the predictive power of baseline variables in the context of a sensitivity analysis. We use data on the number and type of attempts made to obtain outcome data in order to estimate the association between smoking status and the missing data indicator.
Results
We apply our methods to the iQuit smoking cessation trial data. From the sensitivity analysis, we obtain strong evidence that older participants are more likely to provide outcome data. The model for the number and type of attempts to obtain outcome data confirms that age is a good predictor of missing data. There is weak evidence from this model that participants who have successfully given up smoking are more likely to provide outcome data but this evidence does not support the “missing=smoking” assumption. The probability that participants with missing outcome data are not smoking at the end of the trial is estimated to be between 0.14 and 0.19.
Conclusions
Those conducting smoking cessation trials, and wishing to perform an analysis that assumes the data are MAR, should collect and incorporate baseline variables into their models that are thought to be good predictors of missing data in order to make this assumption more plausible. However they should also consider the possibility of Missing Not at Random (MNAR) models that make or allow for less extreme assumptions than “missing=smoking”.
doi:10.1186/1471-2288-12-157
PMCID: PMC3507670  PMID: 23067272
7.  Effect of communicating genetic and phenotypic risk for type 2 diabetes in combination with lifestyle advice on objectively measured physical activity: protocol of a randomised controlled trial 
BMC Public Health  2012;12:444.
Background
Type 2 diabetes (T2D) is associated with increased risk of morbidity and premature mortality. Among those at high risk, incidence can be halved through healthy changes in behaviour. Information about genetic and phenotypic risk of T2D is now widely available. Whether such information motivates behaviour change is unknown. We aim to assess the effects of communicating genetic and phenotypic risk of T2D on risk-reducing health behaviours, anxiety, and other cognitive and emotional theory-based antecedents of behaviour change.
Methods
In a parallel group, open randomised controlled trial, approximately 580 adults born between 1950 and 1975 will be recruited from the on-going population-based, observational Fenland Study (Cambridgeshire, UK). Eligible participants will have undergone clinical, anthropometric, and psychosocial measurements, been genotyped for 23 single-nucleotide polymorphisms associated with T2D, and worn a combined heart rate monitor and accelerometer (Actiheart®) continuously for six days and nights to assess physical activity. Participants are randomised to receive either standard lifestyle advice alone (control group), or in combination with a genetic or a phenotypic risk estimate for T2D (intervention groups). The primary outcome is objectively measured physical activity. Secondary outcomes include self-reported diet, self-reported weight, intention to be physically active and to engage in a healthy diet, anxiety, diabetes-related worry, self-rated health, and other cognitive and emotional outcomes. Follow-up occurs eight weeks post-intervention. Values at follow-up, adjusted for baseline, will be compared between randomised groups.
Discussion
This study will provide much needed evidence on the effects of providing information about the genetic and phenotypic risk of T2D. Importantly, it will be among the first to examine the impact of genetic risk information using a randomised controlled trial design, a population-based sample, and an objectively measured behavioural outcome. Results of this trial, along with recent evidence syntheses of similar studies, should inform policy concerning the availability and use of genetic risk information.
Trial registration
Current Controlled Trials ISRCTN09650496
doi:10.1186/1471-2458-12-444
PMCID: PMC3490832  PMID: 22708638
Genetic; Phenotypic; Risk; Communication; Type 2 diabetes; Physical activity; Behaviour; Randomised controlled trial; Protocol
8.  Timescales of Quartz Crystallization and the Longevity of the Bishop Giant Magma Body 
PLoS ONE  2012;7(5):e37492.
Supereruptions violently transfer huge amounts (100 s–1000 s km3) of magma to the surface in a matter of days and testify to the existence of giant pools of magma at depth. The longevity of these giant magma bodies is of significant scientific and societal interest. Radiometric data on whole rocks, glasses, feldspar and zircon crystals have been used to suggest that the Bishop Tuff giant magma body, which erupted ∼760,000 years ago and created the Long Valley caldera (California), was long-lived (>100,000 years) and evolved rather slowly. In this work, we present four lines of evidence to constrain the timescales of crystallization of the Bishop magma body: (1) quartz residence times based on diffusional relaxation of Ti profiles, (2) quartz residence times based on the kinetics of faceting of melt inclusions, (3) quartz and feldspar crystallization times derived using quartz+feldspar crystal size distributions, and (4) timescales of cooling and crystallization based on thermodynamic and heat flow modeling. All of our estimates suggest quartz crystallization on timescales of <10,000 years, more typically within 500–3,000 years before eruption. We conclude that large-volume, crystal-poor magma bodies are ephemeral features that, once established, evolve on millennial timescales. We also suggest that zircon crystals, rather than recording the timescales of crystallization of a large pool of crystal-poor magma, record the extended periods of time necessary for maturation of the crust and establishment of these giant magma bodies.
doi:10.1371/journal.pone.0037492
PMCID: PMC3364253  PMID: 22666359
9.  Self-help materials for the prevention of smoking relapse: study protocol for a randomized controlled trial 
Trials  2012;13:69.
Background
Most people who stop smoking successfully for a few weeks will return to smoking again in the medium term. There are few effective interventions to prevent this relapse and none used routinely in clinical practice. A previous exploratory meta-analysis suggested that self-help booklets may be effective but requires confirmation. This trial aims to evaluate the effectiveness and cost-effectiveness of a set of self-help educational materials to prevent smoking relapse in the National Health Service (NHS) Stop Smoking Service.
Methods/design
This is an open, randomized controlled trial. The target population is carbon monoxide (CO) verified quitters at four weeks in the NHS stop smoking clinic (total sample size N = 1,400). The experimental intervention tested is a set of eight revised Forever Free booklets, including an introduction booklet and more extensive information on all important issues for relapse prevention. The control intervention is a leaflet that has no evidence to suggest it is effective but is currently given to some patients using NHS stop smoking services.
Two follow-up telephone interviews will be conducted at three and 12 months after the quit date. The primary outcome will be prolonged abstinence from months four to 12 with no more than five lapses, confirmed by a CO test at the 12-month assessment. The secondary outcomes will be seven-day self-report point prevalence abstinence at three months and seven-day biochemically confirmed point prevalence abstinence at 12 months. To assess cost-effectiveness, costs will be estimated from a health service perspective and the EQ-5D will be used to estimate the QALY (Quality Adjusted Life Year) gain associated with each intervention.
The comparison of smoking abstinence rates (and any other binary outcomes) between the two trial arms will be carried out using odds ratio as the outcome statistic and other related statistical tests. Exploratory subgroup analyses, including logistic regression analyses with interaction terms, will be conducted to investigate possible effect-modifying variables.
Discussion
The possible effect of self-help educational materials for the prevention of smoking relapse has important public health implications.
Trial registration
Current Controlled Trials ISRCTN36980856
doi:10.1186/1745-6215-13-69
PMCID: PMC3480895  PMID: 22647290
Smoking relapse; Self-help booklets; Effectiveness; Intervention
10.  Effect on Adherence to Nicotine Replacement Therapy of Informing Smokers Their Dose Is Determined by Their Genotype: A Randomised Controlled Trial 
PLoS ONE  2012;7(4):e35249.
Background
The behavioural impact of pharmacogenomics is untested. We tested two hypotheses concerning the behavioural impact of informing smokers their oral dose of NRT is tailored to analysis of DNA.
Methods and Findings
We conducted an RCT with smokers in smoking cessation clinics (N = 633). In combination with NRT patch, participants were informed that their doses of oral NRT were based either on their mu-opioid receptor (OPRM1) genotype, or their nicotine dependence questionnaire score (phenotype). The proportion of prescribed NRT consumed in the first 28 days following quitting was not significantly different between groups: (68.5% of prescribed NRT consumed in genotype vs 63.6%, phenotype group, difference  =  5.0%, 95% CI −0.9,10.8, p  =  0.098). Motivation to make another quit attempt among those (n  =  331) not abstinent at six months was not significantly different between groups (p  =  0.23). Abstinence at 28 days was not different between groups (p = 0.67); at six months was greater in genotype than phenotype group (13.7% vs 7.9%, difference  =  5.8%, 95% CI 1.0,10.7, p  =  0.018).
Conclusions
Informing smokers their oral dose of NRT was tailored to genotype not phenotype had a small, statistically non-significant effect on 28-day adherence to NRT. Among those still smoking at six months, there was no evidence that saying NRT was tailored to genotype adversely affected motivation to make another quit attempt. Higher abstinence rate at six months in the genotype arm requires investigation.
Trial registration
Controlled-Trials.com ISRCTN14352545.
doi:10.1371/journal.pone.0035249
PMCID: PMC3324463  PMID: 22509402
11.  An explanatory randomised controlled trial of a nurse-led, consultation-based intervention to support patients with adherence to taking glucose lowering medication for type 2 diabetes 
BMC Family Practice  2012;13:30.
Background
Failure to take medication reduces the effectiveness of treatment leading to increased morbidity and mortality. We evaluated the efficacy of a consultation-based intervention to support objectively-assessed adherence to oral glucose lowering medication (OGLM) compared to usual care among people with type 2 diabetes.
Methods
This was a parallel group randomised trial in adult patients with type 2 diabetes and HbA1c≥7.5% (58 mmol/mol), prescribed at least one OGLM. Participants were allocated to a clinic nurse delivered, innovative consultation-based intervention to strengthen patient motivation to take OGLM regularly and support medicine taking through action-plans, or to usual care. The primary outcome was the percentage of days on which the prescribed dose of medication was taken, measured objectively over 12 weeks with an electronic medication-monitoring device (TrackCap, Aardex, Switzerland). The primary analysis was intention-to-treat.
Results
211 patients were randomised between July 1, 2006 and November 30, 2008 in 13 British general practices (primary care clinics). Primary outcome data were available for 194 participants (91.9%). Mean (sd) percentage of adherent days was 77.4% (26.3) in the intervention group and 69.0% (30.8) in standard care (mean difference between groups 8.4%, 95% confidence interval 0.2% to 16.7%, p = 0.044). There was no significant adverse impact on functional status or treatment satisfaction.
Conclusions
This well-specified, theory based intervention delivered in a single session of 30 min in primary care increased objectively measured medication adherence, with no adverse effect on treatment satisfaction. These findings justify a definitive trial of this approach to improving medication adherence over a longer period of time, with clinical and cost-effectiveness outcomes to inform clinical practice.
Trial registration
Current Controlled Trials ISRCTN30522359
doi:10.1186/1471-2296-13-30
PMCID: PMC3499458  PMID: 22480341
Adherence; Brief intervention; Diabetes
12.  Protocol for the ADDITION-Plus study: a randomised controlled trial of an individually-tailored behaviour change intervention among people with recently diagnosed type 2 diabetes under intensive UK general practice care 
BMC Public Health  2011;11:211.
Background
The increasing prevalence of type 2 diabetes poses both clinical and public health challenges. Cost-effective approaches to prevent progression of the disease in primary care are needed. Evidence suggests that intensive multifactorial interventions including medication and behaviour change can significantly reduce cardiovascular morbidity and mortality among patients with established type 2 diabetes, and that patient education in self-management can improve short-term outcomes. However, existing studies cannot isolate the effects of behavioural interventions promoting self-care from other aspects of intensive primary care management. The ADDITION-Plus trial was designed to address these issues among recently diagnosed patients in primary care over one year.
Methods/Design
ADDITION-Plus is an explanatory randomised controlled trial of a facilitator-led, theory-based behaviour change intervention tailored to individuals with recently diagnosed type 2 diabetes. 34 practices in the East Anglia region participated. 478 patients with diabetes were individually randomised to receive (i) intensive treatment alone (n = 239), or (ii) intensive treatment plus the facilitator-led individual behaviour change intervention (n = 239). Facilitators taught patients key skills to facilitate change and maintenance of key behaviours (physical activity, dietary change, medication adherence and smoking), including goal setting, action planning, self-monitoring and building habits. The intervention was delivered over one year at the participant's surgery and included a one-hour introductory meeting followed by six 30-minute meetings and four brief telephone calls. Primary endpoints are physical activity energy expenditure (assessed by individually calibrated heart rate monitoring and movement sensing), change in objectively measured dietary intake (plasma vitamin C), medication adherence (plasma drug levels), and smoking status (plasma cotinine levels) at one year. We will undertake an intention-to-treat analysis of the effect of the intervention on these measures, an assessment of cost-effectiveness, and analyse predictors of behaviour change in the cohort.
Discussion
The ADDITION-Plus trial will establish the medium-term effectiveness and cost-effectiveness of adding an externally facilitated intervention tailored to support change in multiple behaviours among intensively-treated individuals with recently diagnosed type 2 diabetes in primary care. Results will inform policy recommendations concerning the management of patients early in the course of diabetes. Findings will also improve understanding of the factors influencing change in multiple behaviours, and their association with health outcomes.
Trial registration
ISRCTN: ISRCTN99175498
doi:10.1186/1471-2458-11-211
PMCID: PMC3076276  PMID: 21463520
13.  Trial Protocol: Communicating DNA-based risk assessments for Crohn's disease: a randomised controlled trial assessing impact upon stopping smoking 
BMC Public Health  2011;11:44.
Background
Estimates of the risk of developing Crohn's disease (CD) can be made using DNA testing for mutations in the NOD2 (CARD15) gene, family history, and smoking status. Smoking doubles the risk of CD, a risk that is reduced by stopping. CD therefore serves as a timely and novel paradigm within which to assess the utility of predictive genetic testing to motivate behaviour change to reduce the risk of disease. The aim of the study is to describe the impact upon stopping smoking of communicating a risk of developing CD that incorporates DNA analysis. We will test the following main hypothesis:
Smokers who are first degree relatives (FDRs) of CD probands are more likely to make smoking cessation attempts following communication of risk estimates of developing CD that incorporate DNA analysis, compared with an equivalent communication that does not incorporate DNA analysis.
Methods/design
A parallel groups randomised controlled trial in which smokers who are FDRs of probands with CD are randomly allocated in families to undergo one of two types of assessment of risk for developing CD based on either:
i. DNA analysis, family history of CD and smoking status, or
ii. Family history of CD and smoking status
The primary outcome is stopping smoking for 24 hours or longer in the six months following provision of risk information. The secondary outcomes are seven-day smoking abstinence at one week and six month follow-ups. Randomisation of 470 smoking FDRs of CD probands, with 400 followed up (85%), provides 80% power to detect a difference in the primary outcome of 14% between randomised arms, at the 5% significance level.
Discussion
This trial provides one of the strongest tests to date of the impact of communicating DNA-based risk assessment on risk-reducing behaviour change. Specific issues regarding the choice of trial design are discussed.
Trial Registration
ISRCTN: ISRCTN21633644
doi:10.1186/1471-2458-11-44
PMCID: PMC3036624  PMID: 21247480
14.  Impact of informed-choice invitations on diabetes screening knowledge, attitude and intentions: an analogue study 
BMC Public Health  2010;10:768.
Background
Despite concerns that facilitating informed choice would decrease diabetes screening uptake, 'informed choice' invitations that increased knowledge did not affect attendance (the DICISION trial). We explored possible reasons using data from an experimental analogue study undertaken to develop the invitations. We tested a model of the impact on knowledge, attitude and intentions of a diabetes screening invitation designed to facilitate informed choices.
Methods
417 men and women aged 40-69 recruited from town centres in the UK were randomised to receive either an invitation for diabetes screening designed to facilitate informed choice or a standard type of invitation. Knowledge of the invitation, attitude towards diabetes screening, and intention to attend for diabetes screening were assessed two weeks later.
Results
Attitude was a strong predictor of screening intentions (β = .64, p = .001). Knowledge added to the model but was a weak predictor of intentions (β = .13, p = .005). However, invitation type did not predict attitudes towards screening but did predict knowledge (β = -.45, p = .001), which mediated a small effect of invitation type on intention (indirect β = -.06, p = .017).
Conclusions
These findings may explain why information about the benefits and harms of screening did not reduce diabetes screening attendance in the DICISION trial.
doi:10.1186/1471-2458-10-768
PMCID: PMC3019193  PMID: 21167033
15.  Trial Protocol: Using genotype to tailor prescribing of nicotine replacement therapy: a randomised controlled trial assessing impact of communication upon adherence 
BMC Public Health  2010;10:680.
Background
The behavioural impact of pharmacogenomics is untested; informing smokers of genetic test results for responsiveness to smoking cessation medication may increase adherence to this medication. The objective of this trial is to estimate the impact upon adherence to nicotine replacement therapy (NRT) of informing smokers that their oral dose of NRT has been tailored to a DNA analysis. Hypotheses to be tested are as follows:
I Adherence to NRT is greater among smokers informed that their oral dose of NRT is tailored to an analysis of DNA (genotype), compared to one tailored to nicotine dependence questionnaire score (phenotype).
II Amongst smokers who fail to quit at six months, motivation to make another quit attempt is lower when informed that their oral dose of NRT was tailored to genotype rather than phenotype.
Methods/Design
An open label, parallel groups randomised trial in which 630 adult smokers (smoking 10 or more cigarettes daily) using National Health Service (NHS) stop smoking services in primary care are randomly allocated to one of two groups:
i. NRT oral dose tailored by DNA analysis (OPRM1 gene) (genotype), or
ii. NRT oral dose tailored by nicotine dependence questionnaire score (phenotype)
The primary outcome is proportion of prescribed NRT consumed in the first 28 days following an initial quit attempt, with the secondary outcome being motivation to make another quit attempt, amongst smokers not abstinent at six months. Other outcomes include adherence to NRT in the first seven days and biochemically validated smoking abstinence at six months. The primary outcome will be collected on 630 smokers allowing sufficient power to detect a 7.5% difference in mean proportion of NRT consumed using a two-tailed test at the 5% level of significance between groups. The proportion of all NRT consumed in the first four weeks of quitting will be compared between arms using an independent samples t-test and by estimating the 95% confidence interval for observed between-arm difference in mean NRT consumption (Hypothesis I). Motivation to make another quit attempt will be compared between arms in those failing to quit by six months (Hypothesis II).
Discussion
This is the first clinical trial evaluating the behavioural impact on adherence of prescribing medication using genetic rather than phenotypic information. Specific issues regarding the choice of design for trials of interventions of this kind are discussed.
Trial details
Funder: Medical Research Council (MRC)
Grant number: G0500274
ISRCTN: 14352545
Date trial stated: June 2007
Expected end date: December 2009
Expected reporting date: December 2010
doi:10.1186/1471-2458-10-680
PMCID: PMC2996370  PMID: 21062464
16.  Overestimation of physical activity level is associated with lower BMI: a cross-sectional analysis 
Background
Poor recognition of physical inactivity may be an important barrier to healthy behaviour change, but little is known about this phenomenon. We aimed to characterize a high-risk population according to the discrepancies between objective and self-rated physical activity (PA), defined as awareness.
Methods
An exploratory cross-sectional analysis of PA awareness using baseline data collected from 365 ProActive participants between 2001 and 2003 in East Anglia, England. Self-rated PA was defined as 'active' or 'inactive' (assessed via questionnaire). Objective PA was defined according to achievement of guideline activity levels (≥30 minutes or <30 minutes spent at least moderate intensity PA, assessed by heart rate monitoring). Four awareness groups were created: 'Realistic Actives', 'Realistic Inactives', 'Overestimators' and 'Underestimators'. Logistic regression was used to assess associations between awareness group and 17 personal, social and biological correlates.
Results
63.3% of participants (N = 231) were inactive according to objective measurement. Of these, 45.9% rated themselves as active ('Overestimators'). In a multiple logistic regression model adjusted for age and smoking, males (OR = 2.11, 95% CI = 1.12, 3.98), those with lower BMI (OR = 0.89, 95% CI = 0.84, 0.95), younger age at completion of full-time education (OR = 0.83, 95% CI = 0.74, 0.93) and higher general health perception (OR = 1.02 CI = 1.00, 1.04) were more likely to overestimate their PA.
Conclusions
Overestimation of PA is associated with favourable indicators of relative slimness and general health. Feedback about PA levels could help reverse misperceptions.
doi:10.1186/1479-5868-7-68
PMCID: PMC2954949  PMID: 20854659
17.  Impact of an informed choice invitation on uptake of screening for diabetes in primary care (DICISION): randomised trial 
Objective To compare the effect of an invitation promoting informed choice for screening with a standard invitation on attendance and motivation to engage in preventive action.
Design Randomised controlled trial.
Setting Four English general practices.
Participants 1272 people aged 40-69 years, at risk for diabetes, identified from practice registers using a validated risk score and invited to attend for screening.
Intervention Intervention was a previously validated invitation to inform the decision to attend screening, presenting diabetes as a serious potential problem, and providing details of possible costs and benefits of screening and treatment in text and pie charts. This was compared with a brief, standard invitation simply describing diabetes as a serious potential problem.
Main outcome measures The primary end point was attendance for screening. The secondary outcome measures were intention to make changes to lifestyle and satisfaction with decisions made among attenders.
Results The primary end point was analysed for all 1272 participants. 55.8% (353/633) of those in the informed choice group attended for screening, compared with 57.6% (368/639) in the standard invitation group (mean difference −1.8%, 95% confidence interval −7.3% to 3.6%; P=0.51). Attendance was lower among the more deprived group (most deprived third 47.5% v least deprived third 64.3%; P<0.001). Interaction between deprivation and effect of invitation type on attendance was not significant. Among attenders, intention to change behaviour was strong and unaffected by invitation type.
Conclusions Providing information to support choice did not adversely affect attendance for screening for diabetes. Those from more socially deprived groups were, however, less likely to attend, regardless of the type of invitation received. Further attention to invitation content alone is unlikely to achieve equity in uptake of preventive services.
Trial registration Current Controlled Trials ISRCTN 73125647.
doi:10.1136/bmj.c2138
PMCID: PMC2869404  PMID: 20466791
18.  Who will increase their physical activity? Predictors of change in objectively measured physical activity over 12 months in the ProActive cohort 
BMC Public Health  2010;10:226.
Background
The aim was to identify predictors of change in objectively measured physical activity over 12 months in the ProActive cohort to improve understanding of factors influencing change in physical activity.
Methods
ProActive is a physical activity promotion trial that took place in Eastern England (1999-2004). 365 offspring of people with type 2 diabetes underwent measurement of physical activity energy expenditure (PAEE) using heart rate monitoring, fitness, and anthropometric and biochemical status at baseline and 1 year (n = 321). Linear regression was used to quantify the associations between baseline demographic, clinical, psychosocial and behavioural variables and change in PAEE over 12 months. This study is registered as ISRCTN61323766.
Results
ProActive participants significantly increased their PAEE by 0.6 kj/min (SD 4.2, p = 0.006) over one year, the equivalent of around 20 minutes brisk walking/day. Male sex and higher fitness at baseline predicted increase in PAEE. No significant associations were found for any other variables. Very few baseline demographic, clinical, psychosocial and behavioural predictors were associated with change in objectively measured physical activity.
Conclusions
Traditional baseline determinants of self-reported physical activity targeted by behavioural interventions may be relatively weak predictors of change in objectively measured physical activity. Further research is needed to improve our understanding of factors influencing change in physical activity to inform the development and targeting of interventions.
doi:10.1186/1471-2458-10-226
PMCID: PMC2873588  PMID: 20433700
19.  Randomised controlled trial of the effects of physical activity feedback on awareness and behaviour in UK adults: the FAB study protocol [ISRCTN92551397] 
BMC Public Health  2010;10:144.
Background
While there are increasing data implicating poor recognition of physical inactivity as a potential barrier to healthy behaviour change, the efficacy of feedback to promote physical activity is uncertain. Using a randomised controlled trial nested within a population-based cohort study, we plan to test three variations of physical activity feedback against a control group. Our primary objective is to assess the efficacy of physical activity feedback in promoting physical activity behaviour change. Secondary objectives are to determine the influence of feedback on physical activity awareness and cognitions, and to compare behavioural effects by type of feedback.
Methods/Design
We aim to recruit 500 healthy participants aged 30 to 55 years from the ongoing Fenland Study (Cambridge, UK). Following careful phenotyping during baseline measurement (anthropometric, clinical, body composition and fitness measurements, as well as questionnaires assessing self-reported and self-rated physical activity, psychosocial correlates of physical activity behaviour, diet, lifestyle and general health), participants wear a combined heart rate and movement sensor (Actiheart®) for six continuous days and nights. After receipt of the physical activity data (around 2 weeks later), participants are randomly allocated to either a control group (no feedback) or one of three types of personalised physical activity feedback ('simple', 'visualised' or 'contextualised'), and complete repeat measures of self-rated physical activity and psychosocial correlates. Approximately five weeks after receiving feedback, all participants wear the Actiheart® for another six-day follow-up period and complete repeat questionnaires. Values at outcome, adjusted for baseline, will be compared between randomised groups.
Discussion
Given the randomised trial design and use of objective measure of physical activity, this study is likely to provide valuable insights into the efficacy of a feedback intervention in changing physical activity behaviour, as well as the psychological mechanisms involved.
Trial Registration
Current Controlled Trials: ISRCTN92551397
doi:10.1186/1471-2458-10-144
PMCID: PMC2859395  PMID: 20298560
20.  Are people with negative diabetes screening tests falsely reassured? Parallel group cohort study embedded in the ADDITION (Cambridge) randomised controlled trial 
Objective To assess whether receiving a negative test result at primary care based stepwise diabetes screening results in false reassurance.
Design Parallel group cohort study embedded in a randomised controlled trial.
Setting 15 practices (10 screening, 5 control) in the ADDITION (Cambridge) trial.
Participants 5334 adults (aged 40-69) in the top quarter for risk of having undiagnosed type 2 diabetes (964 controls and 4370 screening attenders).
Main outcome measures Perceived personal and comparative risk of diabetes, intentions for behavioural change, and self rated health measured after an initial random blood glucose test and at 3-6 and 12-15 months later (equivalent time points for controls).
Results A linear mixed effects model with control for clustering by practice found no significant differences between controls and people who screened negative for diabetes in perceived personal risk, behavioural intentions, or self rated health after the first appointment or at 3-6 months or 12-15 months later. After the initial test, people who screened negative reported significantly (but slightly) lower perceived comparative risk (mean difference −0.16, 95% confidence interval −0.30 to −0.02; P=0.04) than the control group at the equivalent time point; no differences were evident at 3-6 and 12-15 months.
Conclusions A negative test result at diabetes screening does not seem to promote false reassurance, whether this is expressed as lower perceived risk, lower intentions for health related behavioural change, or higher self rated health. Implementing a widespread programme of primary care based stepwise screening for type 2 diabetes is unlikely to cause an adverse shift in the population distribution of plasma glucose and cardiovascular risk resulting from an increase in unhealthy behaviours arising from false reassurance among people who screen negative.
Trial registration Current controlled trials ISRCTN99175498.
doi:10.1136/bmj.b4535
PMCID: PMC2785870  PMID: 19948642
21.  Impact of a physical activity intervention program on cognitive predictors of behaviour among adults at risk of Type 2 diabetes (ProActive randomised controlled trial) 
Background
In the ProActive Trial an intensive theory-based intervention program was no more effective than theory-based brief advice in increasing objectively measured physical activity among adults at risk of Type 2 diabetes. We aimed to illuminate these findings by assessing whether the intervention program changed cognitions about increasing activity, defined by the Theory of Planned Behaviour, in ways consistent with the theory.
Methods
N = 365 sedentary participants aged 30–50 years with a parental history of Type 2 diabetes were randomised to brief advice alone or to brief advice plus the intervention program delivered face-to-face or by telephone. Questionnaires at baseline, 6 and 12 months assessed cognitions about becoming more physically active. Analysis of covariance was used to test intervention impact. Bootstrapping was used to test multiple mediation of intervention impact.
Results
At 6 months, combined intervention groups (face-to-face and telephone) reported that they found increasing activity more enjoyable (affective attitude, d = .25), and they perceived more instrumental benefits (e.g., improving health) (d = .23) and more control (d = .32) over increasing activity than participants receiving brief advice alone. Stronger intentions (d = .50) in the intervention groups than the brief advice group at 6 months were partially explained by affective attitude and perceived control. At 12 months, intervention groups perceived more positive instrumental (d = .21) and affective benefits (d = .29) than brief advice participants. The intervention did not change perceived social pressure to increase activity.
Conclusion
Lack of effect of the intervention program on physical activity over and above brief advice was consistent with limited and mostly small short-term effects on cognitions. Targeting affective benefits (e.g., enjoyment, social interaction) and addressing barriers to physical activity may strengthen intentions, but stronger intentions did not result in more behaviour change. More powerful interventions which induce large changes in TPB cognitions may be needed. Other interventions deserving further evaluation include theory-based brief advice, intensive measurement of physical and psychological factors, and monitoring of physical activity. Future research should consider a wider range of mediators of physical activity change, assess participants' use of self-regulatory strategies taught in the intervention, and conduct experimental studies or statistical modelling prior to trial evaluation. ISRCTN61323766.
doi:10.1186/1479-5868-6-16
PMCID: PMC2669044  PMID: 19292926
22.  Impact of an informed choice invitation on uptake of screening for diabetes in primary care (DICISION): trial protocol 
BMC Public Health  2009;9:63.
Background
Screening invitations have traditionally been brief, providing information only about population benefits. Presenting information about the limited individual benefits and potential harms of screening to inform choice may reduce attendance, particularly in the more socially deprived. At the same time, amongst those who attend, it might increase motivation to change behavior to reduce risks. This trial assesses the impact on attendance and motivation to change behavior of an invitation that facilitates informed choices about participating in diabetes screening in general practice. Three hypotheses are tested:
1. Attendance at screening for diabetes is lower following an informed choice compared with a standard invitation.
2. There is an interaction between the type of invitation and social deprivation: attendance following an informed choice compared with a standard invitation is lower in those who are more rather than less socially deprived.
3. Amongst those who attend for screening, intentions to change behavior to reduce risks of complications in those subsequently diagnosed with diabetes are stronger following an informed choice invitation compared with a standard invitation.
Method/Design
1500 people aged 40–69 years without known diabetes but at high risk are identified from four general practice registers in the east of England. 1200 participants are randomized by households to receive one of two invitations to attend for diabetes screening at their general practices. The intervention invitation is designed to facilitate informed choices, and comprises detailed information and a decision aid. A comparison invitation is based on those currently in use. Screening involves a finger-prick blood glucose test. The primary outcome is attendance for diabetes screening. The secondary outcome is intention to change health related behaviors in those attenders diagnosed with diabetes. A sample size of 1200 ensures 90% power to detect a 10% difference in attendance between arms, and in an estimated 780 attenders, 80% power to detect a 0.2 sd difference in intention between arms.
Discussion
The DICISION trial is a rigorous pragmatic denominator based clinical trial of an informed choice invitation to diabetes screening, which addresses some key limitations of previous trials.
Trial registration
Current Controlled Trials ISRCTN73125647
doi:10.1186/1471-2458-9-63
PMCID: PMC2666721  PMID: 19232112
23.  Effectiveness of computer-tailored Smoking Cessation Advice in Primary Care (ESCAPE): a Randomised Trial 
Trials  2008;9:23.
Background
Smoking remains a major public health problem; developing effective interventions to encourage more quit attempts, and to improve the success rate of self-quit attempts, is essential to reduce the numbers of people who smoke. Interventions for smoking cessation can be characterised in two extremes: the intensive face-to face therapy of the clinical approach, and large-scale, public health interventions and policy initiatives. Computer-based systems offer a method for generating highly tailored behavioural feedback letters, and can bridge the gap between these two extremes. Proactive mailing and recruitment can also serve as a prompt to motivate smokers to make quit attempts or to seek more intensive help. The aim of this study is to evaluate the effect of personally tailored feedback reports, sent to smokers identified from general practitioners lists on quit rates and quitting activity. The trial uses a modified version of a computer-based system developed by two of the authors to generate individually tailored feedback reports.
Method
A random sample of cigarette smokers, aged between 18 and 65, identified from GP records at a representative selection of practices registered with the GPRF are sent a questionnaire. Smokers returning the questionnaire are randomly allocated to a control group to receive usual care and standard information, or to an intervention group to receive usual care and standard information plus tailored feedback reports. Smoking status and cognitive change will be assessed by postal questionnaire at 6-months.
Discussion
Computer tailored personal feedback, adapted to reading levels and motivation to quit, is a simple and inexpensive intervention which could be widely replicated and delivered cost effectively to a large proportion of the smoking population. Given its recruitment potential, a modest success rate could have a large effect on public health. The intervention also fits into the broader scope of tobacco control, by prompting more quit attempts, and increasing referrals to specialised services. The provision of this option to smokers in primary care can complement existing services, and work synergistically with other measures to produce more quitters and reduce the prevalence of smoking in the UK.
Trial registration
Current Controlled Trials ISRCTN05385712
doi:10.1186/1745-6215-9-23
PMCID: PMC2409293  PMID: 18445279
24.  Protocol for SAMS (Support and Advice for Medication Study): A randomised controlled trial of an intervention to support patients with type 2 diabetes with adherence to medication 
BMC Family Practice  2008;9:20.
Background
Although some interventions have been shown to improve adherence to medication for diabetes, results are not consistent. We have developed a theory-based intervention which we will evaluate in a well characterised population to test efficacy and guide future intervention development and trial design.
Methods and Design
The SAMS (Supported Adherence to Medication Study) trial is a primary care based multi-centre randomised controlled trial among 200 patients with type 2 diabetes and an HbA1c of 7.5% or above. It is designed to evaluate the efficacy of a two-component motivational intervention based on the Theory of Planned Behaviour and volitional action planning to support medication adherence compared with standard care. The intervention is delivered by practice nurses. Nurses were trained using a workshop approach with role play and supervised using assessment of tape-recorded consultations. The trial has a two parallel groups design with an unbalanced three-to-two individual randomisation eight weeks after recruitment with twelve week follow-up. The primary outcome is medication adherence measured using an electronic medication monitor over 12 weeks and expressed as the difference between intervention and control in mean percentage of days on which the correct number of medication doses is taken. Subgroup analyses will explore impact of number of medications taken, age, HbA1c, and self-reported adherence at baseline on outcomes. The study also measures the effect of dispensing medication to trial participants packaged in the electronic medication-monitoring device compared with conventional medication packaging. This will be achieved through one-to-one randomisation at recruitment to these conditions with assessment of the difference between groups in self-report of medication adherence and change in mean HbA1c from baseline to eight weeks. Anonymised demographic data are collected on non-respondents. Central randomisation is carried out independently of trial co-ordination and practices using minimisation to adjust for selected confounders.
Discussion
The SAMS intervention and trial design address weaknesses of previous research by recruitment from a well-characterised population, definition of a feasible theory based intervention to support medication taking and careful measurement to estimate and interpret efficacy. The results will inform practice and the design of a cost-effectiveness trial [ISRCTN30522359].
doi:10.1186/1471-2296-9-20
PMCID: PMC2364626  PMID: 18405345
25.  Psychological impact of screening for type 2 diabetes: controlled trial and comparative study embedded in the ADDITION (Cambridge) randomised controlled trial 
BMJ : British Medical Journal  2007;335(7618):486.
Objective To quantify the psychological impact of primary care based stepwise screening for type 2 diabetes.
Design Controlled trial and comparative study embedded in a randomised controlled trial.
Setting 15 practices (10 screening, five control) in the ADDITION (Cambridge) trial in the east of England.
Participants 7380 adults (aged 40-69) in the top fourth for risk of having undiagnosed type 2 diabetes (6416 invited for screening, 964 controls).
Interventions Invited for screening for type 2 diabetes or not invited (controls), incorporating a comparative study of subgroups of screening attenders. Attenders completed questionnaires after a random blood glucose test and at 3-6 months and 12-15 months later. Controls were sent questionnaires at corresponding time points. Non-attenders were sent questionnaires at 3-6 months and 12-15 months.
Main outcome measures State anxiety (Spielberger state anxiety inventory), anxiety and depression (hospital anxiety and depression scale), worry about diabetes, and self rated health.
Results No significant differences were found between the screening and control participants at any time—for example, difference in means (95% confidence intervals) for state anxiety after the initial blood glucose test was −0.53, −2.60 to 1.54, at 3-6 months was 1.51 (−0.17 to 3.20), and at 12-15 months was 0.57, −1.11 to 2.24. After the initial test, compared with participants who screened negative, those who screened positive reported significantly poorer general health (difference in means −0.19, −0.25 to −0.13), higher state anxiety (0.93, −0.02 to 1.88), higher depression (0.32, 0.08 to 0.56), and higher worry about diabetes (0.25, 0.09 to 0.41), although effect sizes were small. Small but significant trends were found for self rated health across the screening subgroups at 3-6 months (P=0.047) and for worry about diabetes across the screen negative groups at 3-6 months and 12-15 months (P=0.001).
Conclusions Screening for type 2 diabetes has limited psychological impact on patients. Implementing a national screening programme based on the stepwise screening procedure used in the ADDITION (Cambridge) trial is unlikely to have significant consequences for patients' psychological health.
Trial registration Current Controlled Trials ISRCTN99175498.
doi:10.1136/bmj.39303.723449.55
PMCID: PMC1971192  PMID: 17761995

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