To examine the use of extended-release (ER) opioids relative to immediate-release (IR) opioids in chronic opioid prescription episodes, pharmacy claim data from a national health plan database were analyzed. Enrollees having at least 1 pharmacy claim for an opioid formulation between June 2003 and May 2006, and at least 1 year of continuous enrollment after their first observed pharmacy claim were included. Opioid prescription episodes were created by combining contiguous days of therapy, allowing for a maximum of 7 days between refills (>or=8 d = new episode). Outcomes are reported in the form of probabilities and odds ratios (ORs). A total of 3,993,011 opioid prescription episodes were derived from 1,967,898 enrollees. Overall, prescription episodes involving IR preparations (97.7%) were more prevalent than episodes using ER preparations (2.3%). The odds of an ER preparation being prescribed chronically (>or=60 d) were approximately 11 times that of an IR preparation (OR = 10.7); however, the majority of chronic prescription episodes used IR formulations (84.8%). When stratified by prescriber type (specialist vs nonspecialists), the probability of a specialist prescribing ER opioids in these chronic prescription episodes was 19.1% versus 13.7% for nonspecialists. Specialists were about 50% more likely to prescribe ER opioids relative to nonspecialists (OR = 1.49).
Perspective: This analysis suggests that the availability of pain-treatment guidelines, recommendations, and education alone may not be enough to influence opioid-prescribing practices in the treatment of chronic pain.