Real-World Health Care Resource Utilization and Costs Among US Patients with Knee Osteoarthritis Compared with Controls

PURPOSE: To determine the prevalence, healthcare resource utilization and costs (HCRU&C) of knee osteoarthritis (OA) patients versus controls. PATIENTS AND METHODS: Retrospective, matched-cohort administrative claims analysis using IBM MarketScan databases (2011–2017). Newly diagnosed, adult (18+ yrs) knee OA patients identified by ICD9/10 code were matched 1:1 to controls by age, sex, payer, and geography; alpha level set to 0.05. Prevalence was estimated for 2017. All-cause and knee OA-related HCRU&C reported per-patient-per-year (PPPY) over follow-up period up to 4 years. RESULTS: Overall 2017 knee OA prevalence was 4% (615,514 knee OA/15.4M adults). A total of 510,605 patients meeting inclusion criteria were matched 1:1 with controls. The knee OA cohort had mean age 60 years and was 58% female. Versus controls, knee OA patients had significantly more PPPY outpatient (84.5 versus 45.0) and pharmacy (29.8 versus 19.8) claims, and significantly higher PPPY outpatient costs ($12,571 versus $6,465), and pharmacy costs ($3,655 versus $2,038). Knee OA patients incurred $7,707 more PPPY total healthcare costs than controls, of which $4,674 (60.6%) were knee OA-related medical claims and $1,926 (25%) were knee OA-related medications of interest. PPPY costs for nonselective NSAIDs, cyclooxygenase-2 (COX-2) inhibitors, intraarticular hyaluronic acid, non-acute opioids, and knee replacement were higher for knee OA patients than controls. Using median and mean all-cause total cost ($9,330 and $24,550, respectively), the estimated sum cost of knee OA patients in MarketScan ranged from $5.7B to $15B annually. CONCLUSION: This retrospective analysis demonstrated an annual 2017 prevalence of 4.0% (≥18 years) and 13.2% (≥65 years) for newly diagnosed knee OA patients. Compared with controls, all-cause costs were significantly higher for knee OA patients, nearly double that of matched controls, attributable to increased medical and treatment costs and comorbidity treatment burden. Additionally, the estimated annual cost of knee OA treatment was substantial, ranging between $5.7 billion and $15 billion.