Kriemler 2010.
| Study characteristics | ||
| Methods | Study design: cluster‐RCT | |
| Participants |
School inclusion criteria: rural or urban localisation, prevalence of 10% to 30% migrants as in the Swiss population, and, for practical reasons, presence of at least a Grade 1 and a Grade 5 class in each school. Intervention; control schools were located in provinces that were comparable as regards socioeconomic status of the population and recreational facilities at school School exclusion criteria: — Student inclusion criteria: Grades 1 and 5 students in participating schools Student exclusion criteria: — Setting: schools, urban and rural Age group: children Gender distribution: females and males Country/Countries where trial was performed: Switzerland |
|
| Interventions |
Intervention: all children participated in 3 mandatory, 45‐minute PE lessons/week; intervention group participated in 2 additional 45‐minute PE lessons/week. Mandatory PE lessons were given by the usual classroom teachers according to the specified curriculum; additional lessons were taught mostly outdoors by PE teachers. Three to five 2‐ to 5‐minute activity breaks (motor skill tasks ‐ jumping or balancing on 1 leg, power games, coordinative tasks) were provided each day during academic lessons. Children also received daily PA homework (10 minutes' worth) prepared by PE teachers, including aerobic, strength, or motor skill tasks (e.g. brushing teeth while standing on 1 leg, hopping up and down the stairs, jumping rope comparable activities) Comparator: control group continued to participate in the usual, mandatory PE lessons (45 minutes, 3 times/week); they were not informed that an intervention group existed in the other schools (teachers in the control group were aware but did not know the content of the intervention) Duration of intervention: 9 months Duration of follow‐up: 9 months Number of schools: 15 Theoretical framework: socioecological conceptual model |
|
| Outcomes | PA duration Fitness BMI |
|
| Study registration | ISRCTN15360785 (registered retrospectively) | |
| Publication details |
Language of publication: English Funding: non‐commercial funding (Swiss Federal Office of Sports (grant number SWI05‐013), Swiss National Science Foundation (grant number PMPDB‐114401), and Diabetes Foundation of the Region of Basel) Publication status: peer‐reviewed journal |
|
| Stated aim for study | "Our goal was to intervene at the level of the school class, so we did a cluster RCT with a school based stringent PA programme versus traditional PE during 1 school year. We aimed to increase aerobic fitness, PA, and quality of life while decreasing body fat and a composite cardiovascular risk factor score in the intervention group compared with the control group" | |
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Comment: randomised using a random numbers table |
| Allocation concealment (selection bias) | Low risk | Comment: all participants were allocated at 1 point in time following recruitment, so at time of recruitment, allocation was not known |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Quote from publication: "children and parents in the control group were not informed about the existence of the intervention programme in other schools. The teachers in the control group knew about the intervention arm but were not informed about its content" |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote from publication: “assessors responsible for the measurements were blinded to the group allocation for all measurements except skin‐fold and waist circumference measures” (Kriemler 2010, p2) Comment: blinding was in place for relevant outcomes |
| Incomplete outcome data (attrition bias) Anthropometrics, Fitness | Low risk | Comment: intention‐to‐treat principle employed |
| Incomplete outcome data (attrition bias) Physical activity and sedentary time | High risk | Comment: intention‐to‐treat principle employed, but only 82/205 in control group have completed PA data |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes identified a priori were reported on |
| Cluster RCT ‐ Recruitment bias | Low risk | Comment: baseline measures were obtained prior to randomisation |
| Cluster RCT ‐ Baseline imbalance | Low risk | Comment: groups were similar at baseline |
| Cluster RCT ‐ Loss of clusters | High risk | Comment: high loss to follow‐up; no differences between those who completed and those who were missing, but still likely to introduce bias (e.g. only 82/205 in control group have completed PA data) |
| Cluster RCT ‐ Incorrect analysis | Low risk | Comment: clustering accounted for in analysis |