Abstract
More evidence is needed on the potential role of 'booster' interventions in the maintenance of increases in physical activity levels after a brief intervention in relatively sedentary populations. To determine whether objectively measured physical activity, 6 months after a brief intervention, is increased in those receiving physical activity 'booster' consultations delivered in a motivational interviewing (MI) style, either face to face or by telephone. Three-arm, parallel-group, pragmatic, superiority randomised controlled trial with nested qualitative research fidelity and geographical information systems and health economic substudies. Treatment allocation was carried out using a web-based simple randomisation procedure with equal allocation probabilities. Principal investigators and study statisticians were blinded to treatment allocation until after the final analysis only. Deprived areas of Sheffield, UK. Previously sedentary people, aged 40-64 years, living in deprived areas of Sheffield, UK, who had increased their physical activity levels after receiving a brief intervention. Participants were randomised to the control group (no further intervention) or to two sessions of MI, either face to face ('full booster') or by telephone ('mini booster'). Sessions were delivered 1 and 2 months post-randomisation. The primary outcome was total energy expenditure (TEE) per day in kcal from 7-day accelerometry, measured using an Actiheart device (CamNtech Ltd, Cambridge, UK). Independent evaluation of practitioner competence was carried out using the Motivational Interviewing Treatment Integrity assessment. An estimate of the per-participant intervention costs, resource use data collected by questionnaire and health-related quality of life data were analysed to produce a range of economic models from a short-term NHS perspective. An additional series of models were developed that used TEE values to estimate the long-term cost-effectiveness. In total, 282 people were randomised (control = 96; mini booster = 92, full booster = 94) of whom 160 had a minimum of 4 out of 7 days' accelerometry data at 3 months (control = 61, mini booster = 47, full booster = 52). The mean difference in TEE per day between baseline and 3 months favoured the control arm over the combined booster arm but this was not statistically significant (-39 kcal, 95% confidence interval -173 to 95, p = 0.57). The autonomy-enabled MI communication style was generally acceptable, although some participants wanted a more paternalistic approach and most expressed enthusiasm for monitoring and feedback components of the intervention and research. Full boosters were more popular than mini boosters. Practitioners achieved and maintained a consistent level of MI competence. Walking distance to the nearest municipal green space or leisure facilities was not associated with physical activity levels. Two alternative modelling approaches both suggested that neither intervention was likely to be cost-effective. Although some individuals do find a community-based, brief MI 'booster' intervention supportive, the low levels of recruitment and retention and the lack of impact on objectively measured physical activity levels in those with adequate outcome data suggest that it is unlikely to represent a clinically effective or cost-effective intervention for the maintenance of recently acquired physical activity increases in deprived middle-aged urban populations. Future research with middle-aged and relatively deprived populations should explore interventions to promote physical activity that require less proactive engagement from individuals, including environmental interventions. Current Controlled Trials ISRCTN56495859, ClinicalTrials.gov NCT00836459. This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 18, No. 13. See the NIHR Journals Library website for further project information.
Highlights
Rationale There are a number of published systematic reviews of evidence for interventions that increase physical activity.[1,2,3,4,5] More recently the evidence base for brief interventions in primary care has been reviewed.[6]
The lessons learnt in undertaking this trial should inform both the design of future physical activity intervention trials and the development of more effective interventions that are feasible and affordable and have sufficient reach to have an impact in the most deprived, and most sedentary, populations who could benefit most from sustained increases in their physical activity levels
Analysis of secondary outcomes The following continuous secondary outcome measures were assessed at 3 and 9 months post randomisation: l physical component summary score (PCS), mental component summary score (MCS) and Short Form questionnaire-6 Dimensions (SF-6D) scores from the SF-12v2 plus 4 l average minutes per day spent on moderate activity [3–6 metabolic equivalents of task (METs)] l average minutes per day spent on vigorous activity (> 6 METs) l average minutes per day spent on moderate and vigorous activity (≥ 3 METS) l BREQ-2 dimensions l body mass index (BMI) l distance walked during a 12-minute walk test
Summary
Rationale There are a number of published systematic reviews of evidence for interventions that increase physical activity.[1,2,3,4,5] More recently the evidence base for brief interventions in primary care has been reviewed.[6]. In 2006, the National Institute for Health and Care Excellence recommended brief interventions in primary care They called for more work to understand how recent increases in physical activity could be sustained in formerly sedentary people, as studies with longer follow-up times had suggested high levels of relapse. Brief interventions delivered in primary care can increase physical activity levels and are recommended as effective and cost-effective interventions by the National Institute for Health and Care Excellence (NICE).[9,10] the evidence base largely consists of studies with short-term follow-up post intervention and that use self-reported increases in physical activity by trial participants as a primary outcome. The few studies that had followed participants over the long term suggested that approximately half of those who initiate a physical activity programme relapse and return to their previous sedentary lifestyle within 6 months.[11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
