Health and work are intrinsically linked. There is a strong evidence base which shows good health is associated with finding and staying in work, financial and social benefits, as well as advantages for physical and mental health and well-being. Conversely, a strong association exists between worklessness and poorer health outcomes. Work can be therapeutic however, and has been shown to improve health. Overall it has been acknowledged that the benefits of work far outweigh any dis-benefits; thus good health is good business.
Saturday 28th April was the International Labour Organization’s World Day for Healthand Safety at Work; this awareness-raising campaign helps to draw attention to the importance of preventing of occupational accidents and diseases globally. Workplaces are increasingly being recognised as settings to both prevent ill-health and promote health.
Workplace health promotion programmes (WHPP) have been implemented across a number of countries and across a range of industries… But are WHPPs effective? And if so, what makes a WHPP effective?
This month the American Journal of Preventative Medicine published a meta-analysis which explored these questions. Specifically the study aimed to find out:
- Are WHPP aimed at healthy lifestyles effective?
- Does the WHPP study population, method and content impact upon effectiveness?
Three databases were searched (PubMed, Embase and Web of Science) to identify evaluation results of randomised controlled trials (RCTs) of workplace health promotion interventions prior to June 2012.
- Interventions were limited to physical activity, healthy nutrition, weight loss and smoking cessation workplace programmes
- Outcomes of interest included changes in work ability, productivity, sickness absence and self-perceived health
- The search strategy excluded published studies not written in English (n = 111)
- 3,668 studies were initially identified, however only 18 met the pre-defined inclusion criteria for meta-analysis
- Data from those 18 studies was extracted separately by two authors
- Risk of bias was assessed using two tools (the Cochrane Risk of Bias Tool and a checklist based on Cochrane Handbook for Systematic Reviews of Interventions)
Analysis included meta-analyses using a random-effects model (which was appropriate due to high heterogeneity across studies), stratified meta-analysis and meta-regression analyses. Studies were weighted in consideration of both standard error and effect size.
18 studies were eligible and included in the meta-analyses. Study populations ranged from 40 to 860, and reflected a wide range of workplace settings. 11 study interventions aimed at improving physical activity, 4 at weight status, and 4 considered a range of lifestyle factors.
- Overall pooled effect size of workplace health promotion programmes identified was 0.24 (95% CI = 0.14 to 0.34)
- Effect sizes stratified by outcomes were comparable; self-perceived health (0.23, 95% CI 0.13 to 0.33), sickness absence (0.21, 95% CI 0.03 to 0.38), productivity at work (0.29, 95% CI 0.08 to 0.51) and work ability (0.23, 95% CI -0.07 to 0.52)
- Studies with a poor or fair methodologic quality (n=8) were found to have a 2.9 fold higher effect size (0.41, 95% CI 0.20 to 0.62) compared to studies who scored good or excellent (n=4) (0.14, 95% CI 0.08 to 0.19)
- Population characteristics: Intervention effectiveness was larger when study populations included white collar workers (although this was not statistically significant once adjusted for methodologic quality) and mean age was <40 years (this remained significant at 95% level after adjustment for methodologic quality). Intervention effectiveness was not associated with gender.
- Study charactertistics: Where control groups received an intervention the effect sizes were smaller. Randomisation at neither group nor individual level was associated with WHPP effectiveness.
- Intervention charactertistics: WHPP which included frequent (at least weekly) contact were most effective (and this assoicated remained significant after adjustment for methodologic quality). Inclusion of counselling, exercise or education compoents did not influence effectiveness significantly.
The results showed that WHPP do have positive effects on health outcomes (this study specifically looked at work productivity, self-reported health, sickness absence and work ability). The pooled effect size of this study was comparable to previous systematic review findings, however it was clear that the authors were disappointed with what they termed to be a small effect size. It is worth considering that from a public health perspective although 0.24 is not a very large effect size, if WHPPs were able to target large populations the impact could be great!
Professionals developing WHPP should be aware that effectiveness depends on a number of factors, as summarised by the authors below:
This study is the first to show meta-analytically that effectiveness of a WHPP depends on the study population, the intervention content, and the methodologic quality of the study
In particular, I was struck by the influence of contact frequency – the authors noted that WHPP with at least weekly contacts were almost 4 times more effective. It would be interesting to explore whether there is a dose-response relationship between WHPP and outcomes (e.g. why does frequent contact make WHPPs more effective?)
It is interesting to note the author’s observation that studies with poor methodologic quality reported an average effect size 2.9 times larger than good quality studies. This observation is likely to be explained by publication bias (whereby studies which show big effects are more likely to be published compared to those with small or neutral effects). This emphasises the importance of assessing bias of components studies included for systematic review or meta-analysis, and also the importance of good-quality research to measure effectiveness.
Overall this is a good quality study, and we hope to see more robust evidence in the future. We elves know how important this evidence is to encourage health initiatives in the workplace!
Rongen A, Robroek S, van Lenthe F, Burdorf A (2013) Workplace health promotion: a meta-analysis of effectiveness. Am J Prev Med. 2013 Apr;44(4):406-15. Available on-line (not Open Access) http://www.ncbi.nlm.nih.gov/pubmed/23498108
Dame Carol Black Report (2008) “Working for a healthier tomorrow”
Wadell and Burton (2006) “Is work good for your health and well-being?”
Faculty of Public Health and Faculty of Occupational Medicine (2006) “Creating a healthy workplace”