ECONOMIC BURDEN OF OSTEOARTHRITIS MANAGEMENT IN ISLAMABAD AND RAWALPINDI, PAKISTAN: A COMPARATIVE PHARMACOECONOMIC ANALYSIS OF PHARMACOTHERAPY VERSUS TOTAL KNEE ARTHROPLASTY ACROSS PUBLIC AND PRIVATE HEALTHCARE SECTORS

Abstract

Background: Osteoarthritis (OA) is a leading cause of disability worldwide, and its management—ranging from long-term pharmacotherapy to total knee arthroplasty (TKA)—imposes substantial direct and indirect costs on patients and health systems. Comparative, patient-level cost data from Pakistan and other resource-limited settings remain scarce. Objective: To compare the economic burden of pharmacotherapy versus TKA for knee OA across public and private healthcare sectors in Islamabad and Rawalpindi, Pakistan, and to identify independent predictors of TKA cost burden. Methods: This was a comparative, cross-sectional pharmacoeconomic evaluation of 150 patients: 100 receiving non-surgical pharmacotherapy for knee OA and 50 who had undergone primary TKA (25 at a government hospital, 25 at a private hospital) in Islamabad and Rawalpindi. Data on demographics, treatment costs, and resource use were collected via structured patient interviews and hospital billing records and analyzed using descriptive statistics, Mann Whitney U tests, bootstrap resampling (5,000 iterations), and multivariable ordinary least squares regression on log-transformed total economic burden. Results: Mean total economic burden was PKR 1,004,497 in the private sector versus PKR 590,167 in the government sector (1.7-fold difference; Mann Whitney p < 0.0001; Cohen's d = 1.55), driven almost entirely by surgeon fees and hospital-stay charges, which were fully subsidized in government facilities. Mean implant cost did not differ significantly by sector (p = 0.172), but government and private patients received implants from entirely different sources (100% Chinese-manufactured versus 100% Zimmer USA-manufactured implants, respectively). At the observed mean annual pharmacotherapy expenditure of PKR 63,302, cumulative cost equaled government-sector TKA cost after 9.3 years and private-sector TKA cost after 15.9 years. A six-predictor multivariable regression explained 89% of the variance in log-transformed TKA burden (R² = 0.89); bilateral (versus unilateral) procedure (β = 0.526, p < 0.001) and private (versus government) sector (β = 0.368, p < 0.001) were the strongest independent predictors, followed by socioeconomic status (β = 0.118, p = 0.009). Polypharmacy (≥ 3 concurrent medications) was present in 98% of TKA patients and 53% of pharmacotherapy patients. Every low-socioeconomic status patient exceeded the WHO's 40% catastrophic health expenditure threshold regardless of hospital sector. Conclusion: TKA imposes a substantially higher and more variable economic burden than pharmacotherapy, particularly in the private sector, and bilateral procedures and low socioeconomic status independently amplify this burden. The divergent implant sourcing observed between sectors, previously unrecognized in this cohort, raises an equity question that warrants dedicated investigation. These findings support expanded financial protection mechanisms, transparent implant procurement policies, and timely referral pathways for appropriately selected OA patients in Pakistan.