The authors concluded that there was insufficient evidence to assess the effectiveness of single risk factor interventions to promote physical activity among patients affected by at least one chronic disease in primary care settings. The reliability of the conclusions is uncertain given a number of weaknesses (potential for publication bias, small number of studies and small sample sizes).

To assess the effectiveness of interventions to promote physical activity among patients affected by at least one chronic disease in primary care settings.

MEDLINE, CINAHL and EMBASE were searched from inception to 2006 for articles published in English or French. Search terms were reported. Reference lists of relevant articles and reviews were handsearched.

Randomised controlled trials (RCTs) or trials with a quasi-experimental design that evaluated single risk factor interventions to promote physical activity among adult patients (≥18 years) in primary care settings with at least one chronic disease were eligible for inclusion. Studies that recruited geriatric patients (≥65 years) were excluded. The primary outcome measure was level of physical activity.

The included studies were conducted in England, Australia and the Netherlands; most studies assessed interventions that targeted multiple behaviours. Participants included patients with hypertension, hyperlipidaemia, body mass index of more than 25, diabetes or hypercholesterolaemia. The nature and intensity of interventions varied between studies. Interventions included counseling, use of Health Education Authority Booklet, self-help booklet, general practitioner (GP) prescription, health promotion and advice from GP or nurse practitioner. Activity levels were measured using different validated questionnaires (Godin questionnaire, International Physical Activity Questionnaire, Short Questionnaire to assess Health-enhancing Physical Activity).

One reviewer screened studies for inclusion; any uncertainty regarding study eligibility was discussed with a second reviewer until consensus was achieved.

Study quality was assessed using a scale based on the CONSORT statement. Criteria assessed included the adequacy of description of: participants, interventions, sample size, randomisation, statistical methods, results, baseline data, numbers analysed, outcomes and estimates, discussion section, generalisability of findings and overall evidence. Studies had to score 14 out of the maximum 28 points to be included in the review.

Two reviewers independently assessed study quality; disagreements were resolved by consensus.

Descriptive data on the direction of intervention effects were extracted.

The authors did not state how many reviewers extracted data.

The results of included studies were summarised in a narrative synthesis.

Three studies were included (n=1,276): one RCT and two cluster-RCTs. One study had a quality score of 22 points and two achieved a score of 20 points. Follow-up ranged between two to 12 months.

Two studies reported no significant effect of the interventions on levels of physical activity.

In one study there was a significant increase in physical activity with the most intensive intervention only (Godin score 14.4, 95% confidence interval 7.8 to 21).

There was insufficient evidence to assess the effectiveness of single risk factor interventions to promote physical activity among patients affected by at least one chronic disease in primary care settings.

The review question was clearly stated. Several relevant sources were searched. The limitation to papers published in English or French meant there was potential for language and publication biases. The search for unpublished studies was limited and relevant studies may have been missed. Appropriate steps were taken to minimise risks of error and bias during study selection and validity assessment; it was unclear whether similar efforts were taken during data extraction. The study quality assessment criteria appeared appropriate. The decision to combine study results in a narrative synthesis was justified given significant differences between studies in terms of interventions. Only a few studies were included and sample sizes were small.

The reliability of the authors' conclusion is uncertain given a number of weaknesses in the review (potential for publication bias, small number of studies and small sample sizes).

Practice: The authors did not state any implications for practice.

Research: The authors stated that further studies (preferably in collaborative nurse-physician practices) were needed to identify the kinds of interventions that would be effective over the long term in patients with chronic diseases (including osteoarthritis and asthma).

Pfizer Canada; Family Medicine Department, University of Sherbrooke, Quebec.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.