Opioid use in older adults and Medicare Part D

Abstract

Objective: To determine whether the introduction of prescription drug coverage under Medicare Part D increased opioid prescriptions, patient care-seeking for pain, and pain diagnoses among elderly Medicare-eligible adults.

Study setting: Office visits by adults aged 18 years or older from the 2000-2016 National Ambulatory Medical Care Survey (12 375 207 253 office visits), and respondents from the 2000-2017 Medical Expenditure Panel Survey (4 023 418 681 individuals).

Study design: We compared care-seeking for pain, provider-assigned pain diagnoses, and opioid prescriptions before and after the Medicare eligibility age of 65, and before and after Part D's implementation using a regression discontinuity, difference-in-differences design. Analyses were adjusted for age, sex, race, and year.

Principal findings: Patient care-seeking for pain increased by 11.4 office visits per 100 people (95% confidence interval 2.0-20.8), or 29%, in response to the implementation of Part D. Opioid prescriptions and diagnoses of pain-related conditions did not change significantly, but the financing of opioid prescriptions shifted from private to public payers at age 65.

Conclusions: The introduction of Medicare Part D was not associated with increased opioid use among older adults. Rather, opioid use among the elderly has been driven by high levels of opioid use among commercially insured adults who subsequently age into Medicare. Our findings raise the question of whether more judicious prescribing to younger adults coupled with concerted efforts to deprescribe opioids when appropriate may prevent problematic opioid use among the elderly.

Keywords: Medicare Part D; observational data; opioids; pain; population health; prescribing behavior; quasi-experiments.

FIGURE 1

Visits by cohort in National Ambulatory Medical Care Survey (NAMCS). Using the 2000‐2016 NAMCS, the number of visits with a pain‐related reason for visit, where pain was diagnosed, and with opioid prescriptions are shown. The x‐axis measures patient age at the time of visit. The y‐axis measures the number of visits per 100 people by age. Visits were weighted using NAMCS sample weights and normalized to be per 100 people in each age‐year bin to account for changes in cohort sizes over time [Color figure can be viewed at wileyonlinelibrary.com]

FIGURE 2

Visits with an opioid prescription by age in National Ambulatory Medical Care Survey (NAMCS). Using the 2000‐2016 NAMCS, the number of visits with a recorded new or continued opioid prescription is shown. The x‐axis measures patient age at the time of visit. The y‐axis measures the number of visits per 100 people by age. Visits were weighted using NAMCS sample weights and normalized to be per 100 people in each age‐year bin to account for changes in cohort sizes over time. Payment categories were mutually exclusive and the underlying expected primary source of payment was prioritized in the following order (from highest to lowest): Medicare, private, Medicaid, and other [Color figure can be viewed at wileyonlinelibrary.com]