Opioid dispensing and overlap in veterans with non-cancer pain eligible for Medicare Part D.

OBJECTIVES: Pain is the most prevalent problem among veterans, who receive pain diagnoses 5 times more frequently than the general population. Opioids are commonly prescribed for pain, but they have potential for misuse and serious adverse events. The study objective was to evaluate opioid dispensing patterns and predictors for overlap in veterans who are eligible for Medicare Part D benefits.

METHODS: A sample of male and all female veterans aged 66 years and older without cancer in 2005-2009 was included. Overlapping days' supply of opioids were evaluated within the U.S. Department of Veterans Affairs (VA), within Part D, and in cross-system users of VA and Part D-reimbursed pharmacies during 2007-2009. Dispensing patterns were analyzed with t tests and chi-square tests. Predictors of overlap were identified with general estimating equations.

RESULTS: At least 1 opioid was dispensed to 88.5% of the sample. In 2006 after Part D implementation, 55.2% of opioids were dispensed by VA, decreasing to 44.3% in 2009 (P <0.0001). Opioids dispensed from Part D-reimbursed pharmacies had a higher frequency of overlap compared to those filled at a VA facility (P <0.0001). While overlapping days' supply for opioids filled at VA decreased, overlap increased for prescriptions filled at Part D-reimbursed pharmacies (P <0.0001). There was minimal overlap in opioids between systems, but cross-system use increased over the study period. Predictors for overlap include females, Part D enrollment, no VA medication copay, sleep disorders, psychiatric diagnoses, and substance or alcohol abuse (all P <0.01). Veterans who were Hispanic, older, and had higher incomes had lower overlap odds (all P <0.0001).

CONCLUSIONS: Opioids dispensed from Part D-reimbursed pharmacies had a higher frequency of overlapping days' supply as compared to those filled by the VA, but there was minimal overlap between systems. While overlapping opioid prescriptions filled by the VA decreased from 2007 to 2009, overlap increased for prescriptions filled at Part D-reimbursed pharmacies. Tools, such as drug monitoring programs, should be used by VA and non-VA providers to decrease opioid-related harms and misuse.