METHODOLOGICAL CONSIDERATIONS IN COST-OF-ILLNESS STUDIES IN BACK PAIN: A SYSTEMATIC REVIEW

Purpose This review aims to explore the methodologies used for estimating the direct and indirect costs attributed to back pain in developed countries. Methods Six databases were searched to uncover studies about the direct and indirect costs of back pain published in English upto November 2016. Data extracted included study characteristics, cost categories and analysis methods. Results were synthesised descriptively. Results The search identified 8009 potential studies, of which 40 were included for data extraction. The included studies reported data from 14 industrialised countries with considerably varying methodologies. Most of the studies (n=25) followed a retrospective study design and cost perspective was largely societal (n=26). Nearly half of the selected studies included indirect costs in their analysis as well as direct costs; and the proportion of indirect costs in most of the studies far outweighed the direct costs (3:1 ratio). The analysis method used most frequently was the top-down approac...