A scoping review on heterogeneity in rehabilitation research: implications for return to duty in a military population

Abstract: Introduction: Understanding population heterogeneity in rehabilitation research is important, since varying conditions can influence clinical outcomes. The objectives of this scoping review were to review rehabilitation studies that used a heterogeneous group in a civilian or military population, and to discuss the impact of heterogeneity on participation outcomes such as return to duty in the Canadian Armed Forces. Methods: Literature search resulted in extraction of 37 articles, which were sorted according to degree of heterogeneity and type of outcomes examined. Results: The largest number of studies pertained to civilians (n ¼ 26), followed by military (n ¼ 10), and Veterans (n ¼ 1). We found various degrees of heterogeneity in population, setting, intervention, and outcome in these studies. Discussion: Studies extracted seemed to show a superior positive outcome in return to work/duty when the group was heterogeneous. Military rehabilitation studies examining return to duty tended to include a highly heterogeneous population. Future studies pertaining to return to work/duty and using a heterogeneous group should include a wide range of outcomes in the domains of the International Classification of Functioning, Health and Disease. Potential economic benefits in using a heterogeneous-based intervention are also discussed, along with implications for the Canadian Armed Forces.