Healthcare costs associated with osteoarthritis in US patients.

BACKGROUND: Osteoarthritis is a chronic debilitating condition affecting many adults in the United States. This study was to compare pharmacologic treatments and costs for newly diagnosed and existing osteoarthritis patients to assess unmet medication treatment needs and economic burden.
METHODS: This retrospective analysis of de-identified medical and pharmacy insurance claims from the MarketScan(®) databases identified adult patients with an osteoarthritis claim in 2007. The date of the first osteoarthritis claim in 2007 served as the index. Patients were stratified into newly diagnosed and existing cohorts, based on the presence of osteoarthritis claim(s) over the 12-month pre-index period. Utilization of pain-related medications and healthcare costs was assessed in the 12-month postindex period. Multivariate analysis was conducted to adjust costs controlling for cross-cohort differences.
RESULTS: Newly diagnosed osteoarthritis patients (n = 134,584) were younger (66.0 vs. 68.0, P < 0.001), had a higher proportion of men (37.4% vs. 33.9%, P < 0.001) but lower rates of comorbidities than existing patients (n = 123,653). Significantly higher proportions of newly diagnosed patients had an inpatient admission and outpatient office visit. Higher proportions of existing patients utilized a majority of the medication classes examined. Total adjusted osteoarthritis-related costs for newly diagnosed patients were $6,811 annually (95% confidence interval [CI] $6,743 to $6,887), compared to $6,407 (95% CI $6,327 to $6,477) for existing patients. Costs of pain-related prescription drugs associated with osteoarthritis were $965 (95% CI $955 to $975) among new patients, less than the $1,117 (95% CI $1,107 to $1,129) among existing patients.
CONCLUSION: Newly diagnosed osteoarthritis patients incurred higher annual costs, but lower pain-related prescription drug costs in the year following diagnosis than patients with existing osteoarthritis.