|The effectiveness of worksite physical activity programs on physical activity, physical fitness, and health
|Proper K I, Koning M, van der Beek A J, Hildebrandt V H, Bosscher R J, van Mechelen W
This review concluded that workplace physical activity interventions increase levels of activity and reduce musculoskeletal disorders but there was no evidence of effectiveness for other outcomes. The conclusions should be treated with caution because the authors appear to have disregarded some studies that met their inclusion criteria and were included in the review.
The aim was to assess the effectiveness of worksite physical activity programmes on improving physical activity, physical fitness and health.
MEDLINE, EMBASE SPORTDiscus, CINAHL and PsycLIT were searched from 1980 to 2000; the search terms were provided. Reference lists of retrieved studies and the authors' personal databases were also searched. The search was limited to publications in the English language.
Study designs of evaluations included in the review
Randomised controlled studies (RCTs) and non-randomised controlled studies were sought.
Specific interventions included in the review
Studies that were based on worksite interventions, aimed at increasing levels of physical activity, exercise and/or fitness, were sought. The interventions in the included studies consisted variously of self-help or educational programmes and exercise programmes involving aerobics, walking, jogging, swimming, cycling, muscle strengthening, endurance, flexibility and stretching. The duration of follow-up ranged from 5 weeks to 3 years.
Participants included in the review
The inclusion criteria stated that the studies had to be conducted on healthy working people. The participants in the included studies were blue or white-collar workers, home care workers, fire-fighters, nurses, police or military personnel. No details of the age or gender of the participants were given.
Outcomes assessed in the review
The inclusion criteria stated that the studies should measure physical activity levels, health-related fitness or health. Health-related fitness covered cardiorespiratory fitness, muscle flexibility, muscle strength, and body weight and composition. The health outcomes evaluated were general health, fatigue, musculoskeletal disorders, blood-pressure and blood serum lipids. The outcomes in the included studies included self-reported physical activity, strength or flexibility testing, exercise testing, fitness or health levels as measured by questionnaires, body weight, serum lipid levels and blood-pressure.
How were decisions on the relevance of primary studies made?
The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.
Assessment of study quality
The quality of the studies was assessed using criteria based on the Cochrane Back Review Group's quality assessment list. This involved categories such as the method of randomisation (where appropriate), comparability of the baseline characteristics between study groups, drop-outs, intention-to-treat analysis and blinding to assessment. An item was scored positive if it was adequately described and was based on adequate methods. The studies were deemed to be of a high quality if more than 50% of the methodological criteria were scored positive. Two reviewers independently assessed the studies for quality. Any disagreements were resolved by discussion or by consulting a third reviewer.
The authors did not state how the data were extracted for the review, or how many reviewers performed the data extraction. Data were extracted on the study design, study population (including the numbers of participants and the numbers considered in analysis), outcome measures, adherence to the intervention, results (including the effect size) and details of the quality scoring.
Methods of synthesis
How were the studies combined?
The studies were combined in a narrative discussion grouped by outcome. The studies were categorised hierarchically according to the quality criteria scores. Where two or more high-quality studies were identified, the conclusions were based on these and other studies were ignored. Where these were not available, the conclusions were based on lower quality studies, qualified by level of evidence.
How were differences between studies investigated?
Differences between the studies were described in the tables. The studies were grouped according to the quality scoring.
Results of the review
Twenty-six studies (17,006 participants) were included: 15 RCTS (11,454 participants) and 11 non-randomised controlled studies (5,552 participants).
There was strong evidence from two high-quality RCTs that worksite physical activity programmes increased physical activity levels.
The evidence for any improvement in cardiorespiratory fitness was inconclusive. One high-quality RCT showed a significant increase in maximum oxygen consumption; however, this was not supported by the results of a second high-quality RCT.
Three high-quality RCTs found a positive effect of the intervention on back or neck pain, or incidence of back pain.
Limited evidence from two low-quality RCTs showed a reduction in fatigue in the treatment groups.
There was no evidence of any effect of the intervention on serum lipid levels or blood-pressure.
There was inconclusive evidence for changes in muscle flexibility, muscle strength, body weight, body composition and general health with the intervention.
There was strong evidence that worksite physical activity programmes improve levels of physical activity and musculoskeletal disorders, while there was limited evidence for a good effect on fatigue. There was either no evidence for any effect on cardiorespiratory fitness, muscle flexibility, muscle strength, body weight, body composition, general health, blood serum lipids or blood-pressure, or the evidence was inconclusive.
The aims of this review were clearly stated and a number of relevant databases were searched. However, the search was restricted to English language publications and the search terms appeared limited in certain aspects. It is possible that studies were missed, which could have led to bias in the results of the review. Some of the methods of the review were not described (e.g. study selection and data extraction processes). Thus, there is a possibility that bias may have been introduced into the review at these stages. Study quality was assessed and scores were allocated. The studies were grouped hierarchically according to quality scores and subsequently included in, or excluded from the results on the basis of this. However, details of the results of the scoring (i.e. how components contributed to lower or higher scores in each study) were not given. It is difficult to assess the validity of the scoring. However, even high scoring studies appear to have lost a relatively large number of participants to the analyses. In addition, as the authors discussed, adherence to the programmes was poorly reported.
The authors' inclusion criteria stated that they sought any RCT or controlled study. However, if two or more high-quality RCTs were identified, the results from these were discussed and information from other studies appears to have been disregarded. Thus, the 11 non-randomised studies included in the review do not appear to have contributed to the results. The effect size of treatment was not taken into consideration. It may have been more appropriate to make the inclusion criteria more clearly defined and robust (ie. include only randomised comparisons) and then to statistically combine similar studies to determine an overall treatment effect. The results should be considered in view of these comments.
Implications of the review for practice and research
Practice: The authors stated that they support the implementation of worksite physical activity programmes.
Research: The authors stated that more high-quality RCTs are needed.
Proper K I, Koning M, van der Beek A J, Hildebrandt V H, Bosscher R J, van Mechelen W. The effectiveness of worksite physical activity programs on physical activity, physical fitness, and health. Clinical Journal of Sport Medicine 2003; 13(2): 106-117
Subject indexing assigned by NLM
Health Promotion; Humans; Muscle, Skeletal /physiology; Occupational Health; Physical Fitness; Randomized Controlled Trials as Topic; Treatment Outcome; Workplace
Database entry date
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.