Association between industry payments for opioid products and physicians' prescription of opioids: observational study with propensity-score matching

Abstract

Background: Industry marketing to physicians for opioids has received substantial attention as it can potentially influence physicians' prescription of opioids. However, robust evidence demonstrating a causal link between industry payments for opioids and physicians' prescription practice for opioids is lacking.

Methods: Using the national databases of physicians treating Medicare beneficiaries, we examined the association between physicians' receipt of opioid-related industry payments in 2016 and (1) the number of opioids prescribed and (2) the annual expenditures for the opioid products by those physicians in 2017, using propensity-score matching in a 1:1 ratio adjusting for the physician characteristics (sex, years in practice, medical school attended, specialty), the number of opioid prescriptions in 2016, and physicians' financial relationships with industry in 2015. We compared matched pairs of physicians using the estimated effect and paired t-test.

Results: Among 43 778 physicians included after propensity-score matching, physicians who received opioid-related industry payments in 2016 prescribed more opioids (153.8 vs 129.7; adjusted difference (95% CI), 24.1 (19.1 to 29.1)) and accounted for more spending due to opioids ($10 476 vs $6983; adjusted difference (95% CI), $3493 (2854 to 4134)) in 2017, compared with physicians who did not receive payments. The association was larger among primary care physicians than surgeons or specialists. The dose-response analysis revealed that even a small amount of industry payments was sufficient to effectively affect physicians' prescription practice of opioids.

Conclusions: Opioid-related industry payments to physicians in the prior year were associated with a higher number of opioid prescriptions and expenditures for opioid products in the subsequent year.