The review concluded that European literature supported the short-term effectiveness of school-based physical activity promotion programmes; evidence for the effectiveness in other settings was limited and underscored the need for further research. Potential for biases within the review and variability in the included studies limited the reliability of the author’s conclusions.

To evaluate the effectiveness of interventions to promote physical activity among European teenagers.

PubMed, Web of Science, SPORTDiscus and The Cochrane Library were searched from January 1995 to May 2008 for articles published in English. Search terms were reported. Handsearches of the reference lists of review articles and original papers were conducted.

Studies conducted in European teenagers (aged 10 to 19 years) of interventions to promote physical activity versus control were eligible for inclusion. Studies had to be conducted in Europe since 1990 and published since 1995 and had to report objective or self-reported measures of physical activity that were available on at least one follow-up. Studies of multi-component interventions (such as diet, smoking) were eligible for inclusion. Studies were excluded if the only outcome was physical activity in education classes or physical fitness, or if the participants had health problems or specific diseases.

The included studies evaluated school-based interventions, school plus family component interventions, school plus family and community studies, community studies, primary care studies and mail delivery studies in European teenagers. Most studies were controlled trials of intervention versus control. The reported outcome measures were predominantly self-reported. The proportion of boys, where reported, ranged from 38% to 63%.

The authors stated that doubts in study selection were resolved through discussion with a second reviewer. It was unclear how many reviewers were involved in the study selection process.

Quality assessment was undertaken by two reviewers independently using the Quality Assessment Tool for Quantitative Studies. Eight quality items were evaluated, these included blinding, confounders, study design, concealed allocation and withdrawals and drop-outs. Study quality items were graded as strong, moderate or weak methodological quality; a final global quality scored was attained based on the same grading system. Disagreements between reviewers were resolved through discussion or consultation with a third reviewer.

Data were extracted according to the Analysis Grid for Environments Linked to Obesity (ANGELO) framework.

The authors did not state how many reviewers performed data extraction.

A narrative synthesis was presented. Studies were grouped by intervention setting.

Twenty studies were included in the review (n>18,000 participants). Study sample size, where reported, ranged from 78 to 3,224 participants. Duration of follow-up ranged from three weeks to four years. Two studies were deemed strong methodological quality, eight studies were rated moderate and 10 studies were rated as weak. The most common quality issues were a lack of blinding and a lack of control for confounders. There was potential for contamination between control and intervention groups in six studies.

School-based interventions alone or in combination (16 studies): Nine studies evaluated school-based interventions alone, three considered school intervention with family involvement, one evaluated school interventions with community involvement and three studies evaluated school interventions with family and community involvement. Overall, school-based interventions, alone or in combination, led to short-term improvements in physical activity, although these benefits did not transfer to leisure time physical activity. Parents’ involvement appeared to enhance the school-based interventions, as did the support of peers and the influence of direct environmental changes.

Primary care (three studies): Studies in primary care showed mixed effects of interventions; two studies found no effects and one study found positive effects.

Mail-delivered intervention (one study): The one study of a mail-delivered intervention showed positive effects on physical activity levels compared with control.

European literature supported short-term effectiveness of school-based physical activity promotion programmes; evidence for effectiveness in other settings was limited and underscored the need for further research.

Inclusion criteria for the review were clearly defined. Several relevant databases were searched. There was potential for publication and language biases, as only published English-language articles were included; publication bias was not assessed. The authors attempted to minimise reviewer error and bias during quality assessment; they did not state whether such attempts were made for study selection and data extraction. Quality assessment was based on a standard checklist, which indicated generally poor to average study quality. Studies were narratively synthesised, which seemed appropriate for the type of data. Two studies appeared to include adults, which was not the prespecified population. There was a large variability in study duration and outcome measurements.

Potential for biases within the review and quality issues and variability in the included studies limited the reliability of the author’s conclusions.

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

Research: The authors stated that future research should consider parental involvement, partnership with the wider community as a component of school-based interventions, whole community based interventions and interventions conducted in the primary care setting. Further research should also address the sustainability of short-term interventions, aim to develop standardised tools to measure physical activity and aim to examine the independent effects of changes in physical, socio-cultural or political environment on physical activity in teenagers.

Funded by the European Union Public Health Programme (2006323).

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.