New England Journal of Medicine
February 22, 2018  Vol. 378 No. 8
http://www.nejm.org/toc/nejm/medical-journal

Sounding Board
A Framework for Ethical Payment to Research Participants
Luke Gelinas, Ph.D., Emily A. Largent, J.D., Ph.D., R.N., I. Glenn Cohen, J.D., Susan Kornetsky, M.P.H., Barbara E. Bierer, M.D., and Holly Fernandez Lynch, J.D.
The authors propose a framework for evaluating the appropriateness of payments to research participants. They distinguish three acceptable rationales for payment: out-of-pocket expenses, time and burdens of participation, and incentive to participate.