Efficacy of a theory-based behavioural intervention to increase physical activity in an at-risk group in primary care (ProActive UK): A randomised trial

General Practice and Primary Care Research Unit, Department of Public Health and Primary Care, University of Cambridge, UK.
The Lancet (Impact Factor: 45.22). 02/2008; 371(9606):41-8. DOI: 10.1016/S0140-6736(08)60070-7
Source: PubMed


Declining physical activity is associated with a rising burden of global disease. Efforts to reverse this trend have not been successful. We aimed to assess the efficacy of a facilitated behavioural intervention to increase the physical activity of sedentary individuals at familial risk of diabetes.
We enrolled 365 sedentary adults who had a parental history of type 2 diabetes. They were recruited from either diabetes or family history registers at 20 general practice clinics in the UK. Eligible participants were randomly assigned to one of two intervention groups, or to a comparison group. All participants were posted a brief advice leaflet. One intervention group was offered a 1-year behaviour-change programme, to be delivered by trained facilitators in participants' homes, and the other the same programme by telephone. The programme was designed to alter behavioural determinants, as defined by the theory of planned behaviour, and to teach behaviour-change strategies. The principal outcome at 1 year was daytime physical activity, which was objectively measured as a ratio to resting energy expenditure. Analysis was by intention to treat. This study is registered as ISRCTN61323766.
Of 365 patients, we analysed primary endpoints for 321 (88%) for whom we had data after 1 year of follow-up. At 1 year, the physical-activity ratio of participants who received the intervention, by either delivery route, did not differ from the ratio in those who were given a brief advice leaflet. The mean difference in daytime physical-activity ratio, adjusted for baseline, was -0.04 (95% CI -0.16 to 0.08). The physical-activity ratio did not differ between participants who were delivered the intervention face-to-face or by telephone (mean difference -0.05; 95% CI -0.19 to 0.10).
A facilitated theory-based behavioural intervention was no more effective than an advice leaflet for promotion of physical activity in an at-risk group; therefore health-care providers should remain cautious about commissioning behavioural programmes into individual preventive health-care services.


Available from: Ulf Ekelund
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    • "This may have influenced the response rate, as previous researchers have identified lower response rates to research in deprived communities [29, 30]. Furthermore, there is generally an under-representation of individuals from lower socioeconomic groups and ethnic minorities in physical activity interventions313233, which could have led to a greater dropout at each stage of study when comparing the pilot trial and the full trial. The extent to which the lack of external validity in the pilot study impacted the recruitment in the main study was unforeseen. "
    [Show abstract] [Hide abstract] ABSTRACT: Background: Recruitment issues continue to impact a large number of trials. Sharing recruitment information is vital to supporting researchers to accurately predict recruitment and to manage the risk of poor recruitment during study design and implementation. The purpose of this article is to build on the knowledge available to researchers on recruiting to community-based trials. Methods: A critical commentary of the recruitment challenges encountered during the Booster Study, a randomised controlled trial in which researchers investigated the effectiveness of a motivational interviewing style intervention on the maintenance of physical activity. An overview of recruitment is provided, as well as strategies employed to recruit prospective participants and possible barriers to recruitment. Results: Two hundred eighty-two people, 47% of the original target, were recruited through mail-outs, with secondary recruitment pathways yielding no additional participants. The research team encountered problems with recontacting interested participants and providing study materials in non-English languages. A lower response rate to the mail-out and a greater number of non-contactable participants in the full study than in the pilot study resulted in a smaller pool of eligible participants from the brief intervention eligible for recruitment into the randomised controlled trial. Conclusions: Despite using widely accepted recruitment strategies and incorporating new recruitment tactics in response to challenges, the Booster Study investigators failed to randomise a sufficient number of participants. Recruitment in trials of community-based behavioural interventions may have different challenges than trials based on clinical or primary care pathways. Specific challenges posed by the complexity of the study design and problems with staffing and resources were exacerbated by the need to revise upwards the number of mailed invitations as a result of the pilot study. Researchers should ensure study design facilitates recruitment and consider the implications of changing recruitment on the operational aspects of the trial. Where possible, the impact of new strategies should be measured, and recruitment successes and challenges should be shared with those planning similar studies. ISRCTN56495859(registered on 12 February 2009); NCT00836459(registered on 3 February 2009).
    Preview · Article · Dec 2016 · Trials
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    • "Individual−level SES x intention effect size Griffin 2011 Watkinson 2010 Kinmonth 2008 Godino 2012 Marteau 2012 478 544 365 569 633 0.15 [ –0.24 , 0.54 ] –0.14 [ –0.43 , 0.15 ] –0.28 [ –0.75 , 0.20 ] 0.06 [ –0.16 , 0.27 ] –0.01 [ –0.26 , 0.23 ] –0.01 [ –0.14 , 0.11 ] "
    [Show abstract] [Hide abstract] ABSTRACT: Objectives Unhealthy behaviour is more common amongst the deprived, thereby contributing to health inequalities. The evidence that the gap between intention and behaviour is greater amongst the more deprived is limited and inconsistent. We tested this hypothesis using objective and self-report measures of three behaviours, both individual- and area-level indices of socio-economic status, and pooling data from five studies. DesignSecondary data analysis. Methods Multiple linear regressions and meta-analyses of data on physical activity,diet, and medication adherence in smoking cessation from 2,511 participants. ResultsAcross five studies, we found no evidence for an interaction between deprivation and intention in predicting objective or self-report measures of behaviour. Using objectively measured behaviour and area-level deprivation, meta-analyses suggested that the gap between self-efficacy and behaviour was greater amongst the more deprived (B=.17 [95% CI=0.02, 0.31]). Conclusions We find no compelling evidence to support the hypothesis that the intention-behaviour gap is greater amongst the more deprived.
    Full-text · Article · Aug 2015 · British Journal of Health Psychology
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    • "Behavior modification in general, and " comprehensive lifestyle interventions " in particular [10] are currently the first recommended step in obesity management. However, so far, randomized controlled trials evaluating the effectiveness of programs that target lifestyle behavior have shown mixed effects and, if effective, they have generally resulted in only small changes in target behav- iors1112131415 . In addition, the evidence shows that relatively little if any weight loss accomplished in treatment programs is maintained over the long term [16] . "
    [Show abstract] [Hide abstract] ABSTRACT: Relapse is high in lifestyle obesity interventions involving behavior and weight change. Identifying mediators of successful outcomes in these interventions is critical to improve effectiveness and to guide approaches to obesity treatment, including resource allocation. This article reviews the most consistent self-regulation mediators of medium- and long-term weight control, physical activity, and dietary intake in clinical and community behavior change interventions targeting overweight/obese adults. A comprehensive search of peer-reviewed articles, published since 2000, was conducted on electronic databases (for example, MEDLINE) and journal reference lists. Experimental studies were eligible if they reported intervention effects on hypothesized mediators (self-regulatory and psychological mechanisms) and the association between these and the outcomes of interest (weight change, physical activity, and dietary intake). Quality and content of selected studies were analyzed and findings summarized. Studies with formal mediation analyses were reported separately. Thirty-five studies were included testing 42 putative mediators. Ten studies used formal mediation analyses. Twenty-eight studies were randomized controlled trials, mainly aiming at weight loss or maintenance (n = 21). Targeted participants were obese (n = 26) or overweight individuals, aged between 25 to 44 years (n = 23), and 13 studies targeted women only. In terms of study quality, 13 trials were rated as "strong", 15 as "moderate", and 7 studies as "weak". In addition, methodological quality of formal mediation analyses was "medium". Identified mediators for medium-/long-term weight control were higher levels of autonomous motivation, self-efficacy/barriers, self-regulation skills (such as self-monitoring), flexible eating restraint, and positive body image. For physical activity, significant putative mediators were high autonomous motivation, self-efficacy, and use of self-regulation skills. For dietary intake, the evidence was much less clear, and no consistent mediators were identified. This is the first systematic review of mediational psychological mechanisms of successful outcomes in obesity-related lifestyle change interventions. Despite limited evidence, higher autonomous motivation, self-efficacy, and self-regulation skills emerged as the best predictors of beneficial weight and physical activity outcomes; for weight control, positive body image and flexible eating restraint may additionally improve outcomes. These variables represent possible targets for future lifestyle interventions in overweight/obese populations.
    Full-text · Article · Apr 2015 · BMC Medicine
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