Article The Uneven Foci of Work Disability Research Across Cause-based and Comprehensive Social Security Systems Ellen MacEachen 1 , Sharanya Varatharajan 1 , Bronson Du 1 , Emma Bartel 1 , and Kerstin Ekberg 2 Abstract This scoping review identified what kinds of work disability policy issues are critiqued in articles published in countries with cause-based versus comprehen- sive welfare systems. Drawing on a review of work disability policy research, we identified 74 English-language, peer-reviewed articles that focused on program adequacy and design. Articles on cause-based systems dwelled on system fairness and policies of proof of entitlement, while those on comprehensive systems focused more on system design complexities relating to worker inclusion and scope of medical certificates. Overall, we observed a clear difference in the nature of problems examined in the different systems. Gaps in work disability policy literature are identified, and challenges for comparative policy research are discussed. 1 School of Public Health and Health Systems, University of Waterloo, Waterloo, Ontario, Canada 2 Department of Medical and Health Sciences, Linkoping University, Linkoping, Sweden Corresponding Author: Ellen MacEachen, School of Public Health and Health Systems, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada. Email: ellen.maceachen@uwaterloo.ca International Journal of Health Services 0(0) 1–23 ! The Author(s) 2018 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/0020731418809857 journals.sagepub.com/home/joh