Hsieh1 PH, et al. - This study was intended to map the existing evidence concerning cost of illness of  rheumatoid arthritis (RA), as the treatment pathway evolves in the biologic era, and evaluate how costs have been assessed and calculated, in order to assemble and appropriately interpret available data. Researchers conducted systematic review of studies to calculate the costs of patients with RA. They searched multiple electronic databases to distinguish studies published between 2000 and 2019. They further assessed reported total costs and cost components according to the study and population characteristics. Applying Cochran-Armitage test, statistically significant trends in increasing or decreasing proportions over time were ascertained. A reducing trend in inpatient costs chronologically implied a cost shift in other components of direct costs. With work disability being the main cost component, indirect costs still contributed a considerable proportion of total costs. The results suggest that economic analyses that do not incorporate or appropriately assess indirect costs will underestimate the full economic effect of RA.