Multi-Study Spotlight: Timing and the Cost-Effectiveness of Back Pain RTW Interventions

h2. Spotlight on article published in

h2. "+Occupational and Environmental Medicine+":http://oem.bmj.com/content/67/11/744.short

_IBI Spotlights call attention to important health and productivity findings from peer-reviewed work by external researchers. Unless otherwise stated, the authors are not affiliated with IBI, nor was the research executed on IBI’s behalf. IBI members are encouraged to obtain the original articles from the copyright holder._

h2. What is the Issue?

Patterns of return to work (RTW) from low back pain-related absence indicate a phased approach to intervention, with more structured RTW interventions most appropriate later in the duration of an absence spell. However, there is little evidence on the optimal timing of structured interventions from either a productivity of cost-benefit standpoint.

h2. What are the findings/solutions?

The cost-effectiveness of a structured RTW for back pain-related absences is determined by the effectiveness of the intervention, the natural speed of RTW from absence, the costs of the intervention relative to workers’ daily wages, and when it is applied. Based on days of sick leave regained as productive work days, the optimal time period to start an intervention is somewhere between 8 and 12 weeks after the first day of absence. Structured interventions that occur too soon after absence are unlikely to have additional benefit.

h2. Journal Citation

van Duijn, M., Eijkemans, M. J., Koes, B. W., Koopmanschap, M. A., Burton, K. A., & Burdorf, A. (2010). The effects of timing on the cost-effectiveness of interventions for workers on sick leave due to low back pain. _Occupational and Environmental Medicine_, 67(11), 744-750.

h2. Objectives

To examine how the timing of structured interventions for employees on sick leave due to low back pain impacts the likelihood of RTW and the costs and benefits of such interventions.

h2. Method

A literature review of studies was conducted to establish reasonable time curves for the likelihood of RTW from a low back pain absence. Studies were included if the study population included workers on sickness absence due to low back pain, the duration of absence was determined from the first sick day, and RTW from the absence was the outcome. Randomized-controlled trials (RCT) were excluded to best assess the natural course of RTW. A second review was conducted to establish the effect of interventions on RTW. Studies were included if they were RCTs of RTW interventions for workers’ back pain-related absences, RTW was an outcome variable, and hazard-ratios or rate ratios for RTW were presented in the article. The results from both reviews were fitted to a mathematical function that simulated different RTW curves when interventions were applied at different time points. The final results were subjected to cost-benefit analysis (not including unrelated treatments or opportunity costs such missed revenues or co-workers’ overtime).

h2. Results

Four studies with suitable RTW curves were identified, and the two studies with the greatest contrast in curves were selected for the final models. Ten RCT studies were identified, five of which had information on costs and benefits.

Interventions were more beneficial under simulated conditions of slower RTW curves (i.e., when longer durations were required to return all absent employees to work). The optimal time period to start an intervention is somewhere between 8 and 12 weeks after the first day of absence. However, the relative costs and benefits of the timing of intervention vary by the price of the intervention. Interventions that cost 10 times the average worker’s daily wages exceeded the benefits in productivity gains under the fast curve condition. Under the slow curve assumption for the least powerful interventions, an intervention that cost 10 times the average worker’s daily wages were cost-effective if they started somewhere 4 and 10 weeks after the first day of absence. There was no cost benefit at 15 times average daily wages.

h2. Conclusion

The cost-effectiveness of a structured RTW for back pain-related absences is determined by the effectiveness of the intervention, the natural speed of RTW from absence, the costs of the intervention relative to workers’ daily wages, and when it is applied. Based on days of sick leave regained as productive work days, the optimal time period to start an intervention is somewhere between 8 and 12 weeks after the first day of absence. Structured interventions that occur too soon after absence are unlikely to have additional benefit.