Patients worried about rising health care costs are increasingly citing higher prescription drug copay charges.

Consumers responding to an online survey by Weiss Ratings ranked rising Rx copays as the biggest change in their health insurance expenses last year. According to the researchers, better than 1 in 3 Americans now considers higher drug copays as the most burdensome increase in health expenses.

Those findings are not surprising in view of the results of a separate study of consumers with prescription drug insurance by the Kaiser Family Foundation. That research found that over the past 4 years copayments for generic drugs have increased by an average of more than 50%, while brand-name drug copays have jumped between 50% and 90%.

Mr. Rankin is a freelance medical writer.