The economic burden of osteoarthritis in Americans: analysis from a privately insured population

      Purpose: Osteoarthritis (OA) is the most common form of arthritis and the leading cause of working age disabilities. Over 27 million US adults have clinical OA, and different types of burdens exist based on the disease stages and locations. The burden of OA by joint location, age, or comorbidity has not been well studied. The objective of this study was to assess the excess health care resource use and costs attributable to OA by joint location, age, and comorbidity in a privately insured population.
      Methods: 428,084 OA patients aged ≥18 were selected from a US-based employer claims database (1999–2011). Controls were selected from the same database by matching OA patients 1:1 by age, gender, index date, and follow-up time to patients who never had OA in their claims histories. Descriptive analyses were used to compare baseline characteristics and study period medical resource use and costs, inflated to 2011 US dollars using annual medical Consumer Price Index data (Bureau of Labor Statistics). Statistical comparisons were made using McNemar’s test for categorical variables and the Wilcoxon signed-rank test for continuous variables.
      Table 1OA-Related Mean Cumulative One-Year Costs by Joint Location, Age, and Comorbidity
      SubgroupTotal Medical*InpatientOutpatientPhysical or Occupational TherapyPharmacy
      Joint location
      Age group, y
      CVD = cardiovascular disease; OA = osteoarthritis.
      Total medical costs are equal to the sum of inpatient, outpatient, and emergency room costs, excluding physical or occupational therapy and pharmacy costs.
      Costs for patients ≥65 are underestimated because payments observed here are supplements to Medicare.
      ConConclusions: Patients with OA incur greater medical and pharmacy costs than those without OA. The burden of OA varies substantially by joint location. Surgical procedures are the most significant cost among all categories, and therefore is also one of the main drivers of the total cost. In contrast, pharmacy costs are rather small due to no disease-modifying OA drug (DMOAD) available. Hand OA had lower costs than knee and hip OA due to lack of DMOADs and effective surgery. In summary, OA presents a great disease and economic burden. The current treatment options are limited to generic symptom-modifying drugs and late-stage surgical management of the disease, but the latter is only available for certain joints.