Association of opioid utilization management with prescribing and overdose

Continuity of opioid prescribing among older adults on long-term opioids

OBJECTIVES

To describe the continuity of opioid prescribing and prescriber characteristics among older adults with chronic noncancer pain (CNCP) who are on long-term opioid therapy (LTOT) and to evaluate the association of continuity of opioid prescribing and prescriber characteristics with the risk of opioid-related adverse events.

STUDY DESIGN

Nested case-control design.

METHODS

This study employed a nested case-control design using a 5% random sample of the national Medicare administrative claims data for 2012-2016. Eligible individuals experiencing a composite outcome of opioid-related adverse events were defined as cases and matched to controls using incidence density sampling. Continuity of opioid prescribing (operationalized using the Continuity of Care Index) and prescriber specialty were assessed among all eligible individuals. Conditional logistic regression was conducted to assess the relationships of interest after accounting for known confounders.

RESULTS

Individuals with low (odds ratio [OR], 1.45; 95% CI, 1.08-1.94) and medium (OR, 1.37; 95% CI, 1.04-1.79) continuity of opioid prescribing were found to have greater odds of experiencing a composite outcome of opioid-related adverse events compared with individuals with high prescribing continuity. Fewer than 1 in 10 (9.2%) older adults starting a new LTOT episode received at least 1 prescription from a pain specialist. Receiving a prescription from a pain specialist was not significantly associated with the outcome in adjusted analyses.

CONCLUSIONS

We found that higher continuity of opioid prescribing, but not provider specialty, was significantly associated with fewer opioid-related adverse outcomes among older adults with CNCP.

Utilization Management in the Medicare Part D Program and Prescription Drug Utilization

Medicare Part D has significantly enhanced access to prescription drugs among Medicare beneficiaries. However, the recent rapid rise of utilization management policies in the Medicare Part D program may have adversely affected access to prescription drugs. I study the effects of expected and observed exposure to utilization management in prescription drug utilization using Medicare Part D claims data from 2009 to 2016 and an instrumental variables strategy based on the interaction of lagged health status and the set of plans available to each beneficiary. I find that the expected share of spending subject to utilization management increases the observed share, with the smallest effect for prior authorization. Increases in the expected share of drug spending subject to prior authorization increases Part D spending by $122.27 per percentage point, with almost three-quarters of this increase being paid by the Medicare program, rather than beneficiaries or plans. Comparable increases in step therapy and quantity limit exposure increase spending by $46 and decrease spending by $31, respectively. Interestingly, increased exposure to prior authorization and quantity limits increases the average price per 30-day prescription.