OBJECTIVES : Opioid use is prevalent in osteoarthritis (OA) patients to manage OA-related pain. The objective of this study is to describe the prevalence of opioid use and healthcare expenditures in OA patients by patient reported pain severity.

METHODS : Adult OA patients with valid pain scores at OA diagnosis were identified between 1/1/2002 and 9/30/2016 in the MarketScan Claims and Electronic Medical Records Database (CED). Date of pain score was the index date; 12 months continuous enrollment before and after the index date was required. Patients with baseline opioid use or joint replacement during the observation period were excluded. Four pain severity cohorts, based on patient reported pain score at diagnosis, were used: none (0), mild (1-3), moderate (4-6), severe (>6). Opioid use and healthcare expenditures were measured during follow-up and compared by baseline pain severity.

RESULTS : 3,984 OA patients met the patient selection criteria; mean patient age was 66 years and 58% were women. 65% of patients had pain at diagnosis (15% mild, 26% moderate, 24% severe). Strong opioid use was more prevalent in patients with mild (27%), moderate (28%), and severe pain (36%) relative to patients without pain (18%, p<0.001 for all); prevalence of strong opioid use was similar in patients with mild and moderate pain (p=0.59). Patients with severe pain had significantly higher mean expenditures ($16,796) than patients with no pain; p=0.04) and patients with mild pain (p<0.01). Mean healthcare expenditures in patients with moderate ($14,106) or mild ($12,235) were not significantly higher than patients with no reported pain ($14,342).

CONCLUSIONS : Though highest rates of strong opioid use were observed in patients with severe pain, strong opioid use was also prevalent in patients with mild pain. Further research is necessary to assess whether use of strong opioids is consistent with treatment guidelines for patients with mild OA-related pain.