Effectiveness of physical activity promotion based in primary care: systematic review and meta-analysis of randomised controlled trials

Abstract

Objectives: To determine whether trials of physical activity promotion based in primary care show sustained effects on physical activity or fitness in sedentary adults, and whether exercise referral interventions are more effective than other interventions.

Design: Systematic review and meta-analysis of randomised controlled trials.

Data sources: Medline, CINAHL, PsycINFO, EMBASE, SPORTDiscus, Centre for Reviews and Dissemination, the Cochrane Library, and article reference lists.

Review methods: Review of randomised controlled trials of physical activity promotion in sedentary adults recruited in primary care, with minimum follow-up of 12 months, reporting physical activity or fitness (or both) as outcomes, and using intention to treat analyses. Two reviewers independently assessed studies for inclusion, appraised risk of bias, and extracted data. Pooled effect sizes were calculated using a random effects model.

Results: We included 15 trials (n=8745). Most interventions took place in primary care, included health professionals in delivery, and involved advice or counselling given face to face or by phone (or both) on multiple occasions. Only three trials investigated exercise referral. In 13 trials presenting self reported physical activity, we saw small to medium positive intervention effects at 12 months (odds ratio 1.42, 95% confidence interval 1.17 to 1.73; standardised mean difference 0.25, 0.11 to 0.38). The number needed to treat with an intervention for one additional sedentary adult to meet internationally recommended levels of activity at 12 months was 12 (7 to 33). In four trials reporting cardiorespiratory fitness, a medium positive effect at 12 months was non-significant (standardised mean difference 0.51, -0.18 to 1.20). Three trials of exercise referral found small non-significant effects on self reported physical activity at 12 months (odds ratio 1.38; 0.98 to 1.95; standardised mean difference 0.20, -0.21 to 0.61).

Conclusions: Promotion of physical activity to sedentary adults recruited in primary care significantly increases physical activity levels at 12 months, as measured by self report. We found insufficient evidence to recommend exercise referral schemes over advice or counselling interventions. Primary care commissioners should consider these findings while awaiting further trial evaluation of exercise referral schemes and other primary care interventions, with longer follow-up and use of objective measures of outcome.

Conflict of interest statement

Competing interests: All authors have completed the Unified Competing Interest form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: support for the submitted work from the NIHR and University of Cambridge; no financial relationships with commercial entities that might have an interest in the submitted work; no other relationships or activities that could appear to have influenced the submitted work other than their involvement in current primary research in the topic area of the systematic review (ALK, SSu, and GO) and clinical practice in primary care (GO) (ALK is principal investigator of the MRC ProActive trial, SSu and ALK are involved in NIHR funded research on brief interventions to promote physical activity (RP-PG-0608-10079), GO is a clinician in a general practice that uses exercise referral schemes).

Figures

Fig 1 Study selection flow diagram. *Each paper might have more than one reason for exclusion

Fig 2 Funnel plots comparing interventions of physical activity promotion with control interventions for studies reporting dichotomous or continuous outcome data on self reported physical activity

Fig 3 Individual study and pooled effects of physical activity promotion on self reported physical activity at 12 months (dichotomous data). Random effects model used. 95% CI=95% confidence intervals; IV=inverse variance

Fig 4 Individual study and pooled effects of physical activity promotion on self reported physical activity at 12 months (continuous data). Random effects model used. SD=standard deviation; 95% CI=95% confidence intervals; IV=inverse variance

Fig 5 Individual study and pooled effects of physical activity promotion on cardiorespiratory fitness at 12 months. Random effects model used. SD=standard deviation; 95% CI=95% confidence intervals; IV=inverse variance

Fig 6 Individual study and pooled effects of physical activity promotion on self reported physical activity at 12 months, exercise referral interventions only (dichotomous data). Random effects model used. 95% CI=95% confidence intervals; IV=inverse variance

Fig 7 Individual study and pooled effects of physical activity promotion on self reported physical activity at 12 months, exercise referral interventions only (continuous data). Random effects model used. SD=standard deviation; 95% CI=95% confidence intervals; IV=inverse variance

Fig 8 Change in percentage of participants meeting physical activity recommendations between baseline and 12 months of follow-up. Recommendations involved ≥150 min/week physical activity of moderate intensity, for all studies apart from Lamb (≥120 min/week activity of moderate intensity) and Harrison (≥90 min/week activity of moderate intensity). The Jimmy study and the Activity Counseling Trial had 14 and 24 months of follow-up, respectively