Hospital, pharmacy, and outpatient costs for osteoarthritis and chronic back pain

We examined the direct medical costs for patients with osteoarthritis (OA) and chronic back pain (CBP) in comparison to similar patients not treated for these conditions.

All persons age 18 years and over enrolled in the Lovelace Health Plan (LHP) who had at least 2 outpatient or one inpatient visits during the study period (June 30, 2000 to July 1, 2001) for OA or CBP were identified using discharge billing records. Each patient with OA or CBP was matched to 3 persons of the same age group, sex, and ethnicity, and then utilization and pharmacy records for each study subject were abstracted for comparison.

The prevalence of OA and CBP increased with age (11.0% and 7.2% of persons in the 75-79 age group, respectively), although more than two-thirds of OA and CBP patients in the LHP were below age 65. Patients with OA or CBP were more than 3 times more likely than controls to be admitted to hospital, and their average length of stay, costs per hospital day, and readmission rate were all significantly higher (p < 0.01). However, only 58.8% of the excess admissions in the OA group and 48.8% of the excess admissions in the CBP group were attributed to musculoskeletal disease. Outpatient costs were more than doubled among both OA and CBP cases (mean annual outpatient costs of US dollars 4684 and US dollars 4350, respectively), with increased costs seen in all service areas. Prescription drug costs for OA patients (mean average wholesale price, AWP, US dollars 1184) were increased by 102%, with the greatest increases seen in the use of nonsteroidal antiinflammatory drugs (NSAID), gastric acid secretion reducers, and antidepressants. Prescription drug costs for CBP patients were increased by 107% (mean AWP US dollars 1331), with the greatest increases seen in the use of antidepressants, NSAID, narcotics, and gastric acid secretion reducers.

Health services and prescription medication costs for patients with OA and CBP were more than double those of matched controls. Much of the increased utilization occurred in areas not commonly associated with musculoskeletal conditions.