Drivers of Unequal Healthcare Costs in the Nonoperative Treatment of Late-Stage Knee Osteoarthritis Prior to Primary Total Knee Arthroplasty.

Abstract

In the United States, patients with late-stage knee osteoarthritis (OA) often undergo several nonoperative treatments and related procedures prior to total knee arthroplasty. The costs of these treatments and procedures are substantial, and the variation in healthcare costs among different groups of patients may exist. The purpose of this study is to examine these costs and determine the drivers of costs in patients with the highest healthcare expenditure. An observational cohort study was conducted using the IBM Watson Health MarketScan databases from January 1, 2017 to December 31, 2019. The primary outcome was the cost of payments for nonoperative procedures which included (i) physical therapy (PT), (ii) bracing, (iii) intra-articular injections: professional fee, hyaluronic acid (IA-HA), and corticosteroids (IA-CS), (iv) medication: nonsteroidal anti-inflammatory drugs (NSAIDs), opioids, and acetaminophen, and (v) knee-specific imaging. Among the 24,492 patients included in the study, the total payments per patient for nonoperative care were $3,735 ± 3,049 in the highest payment quartile (Q4) and $137 ± 70 in the lowest payment quartile (Q1). Per-patient-per-month costs generally increased across quartiles for procedures. Comparing Q4 to Q1, the largest changes in prevalence were found in IA-HA (348×), bracing (10×), and PT (7×). Patients who were prescribed IA-HA and PT had a 28.3-times and 4.8-times greater likelihood, respectively, to be a higher-paying patient. Unequal healthcare costs in the nonoperative treatment of late-stage knee OA are driven by differences in prevalent management strategies. Overall healthcare expenditure may be reduced if only guideline-concordant treatments are used.