Out-of-pocket spending and medication adherence among dialysis patients in twelve countries.

Few studies have examined drug costs and adherence in similar patient cohorts across countries. Using representative samples of hemodialysis patients from twelve countries, we examined out-of-pocket medication spending and cost-related nonadherence. Mean monthly spending ranged from $8 in the United Kingdom to $114 in the United States. The proportion of patients reporting nonadherence because of cost ranged from 3 percent in Japan to 29 percent in the United States. Out-of-pocket spending was related to national pharmaceutical financing policies and predicted national nonadherence rates. However, inconsistencies in the relationship between patient costs and nonadherence suggested that other social or policy factors also matter.