Medicaid-medicare transitional kinks.

• Position: Affordable Care Act

When Medicare Prescription Drug Coverage started in 2006, many experts voiced concerns about disabled patients with serious mental illness making the transition from Medicaid to Medicare. A study by Harvard Medical School researchers at the Harvard Pilgrim Health Care Institute, Boston, Mass., is one of the first to examine the impact of the transition on mentally ill populations. It found that effects on the use of essential and sometimes lifesaving drugs for these patients varied greatly by state.

Mentally ill patients transitioning from Medicaid to Medicare Part D in states with strict limits on coverage benefited from the change, while those transitioning from states with more generous coverage had less satisfactory outcomes.

The study performed time-series analysis for patients, comparing states that capped monthly prescription fills to states with no prescription limits. Researchers considered Medicaid and Medicare claims for patients who lived in the community were under 65 years old, disabled, enrolled in both Medicaid and Medicare, and who had schizophrenia or bipolar disorder.

Transition to Part D in states with limited drug coverage reduced the number of cases of untreated mental illness, which can result in...