Antiretroviral treatment switching and its association with economic outcomes and adverse treatment effects among commercially insured and Medicaid-enrolled patients with HIV in the United States
BACKGROUND: Antiretroviral therapy (ART) of HIV typically involves the use of 2 nucleoside reverse transcriptase inhibitors plus a third agent (eg, protease inhibitor). It has been shown that over the course of treatment, a proportion of patients switch their ART for various reasons (eg, tolerability, long-term toxicities). We hypothesize that there is a relationship between ART treatment switching and economic and clinical outcomes among HIV patients. OBJECTIVE: To determine whether switching ART regimens is associated with greater health care costs, resource use, and adverse treatment effects. METHODS: Administrative health care claims were used to identify commercially insured and Medicaid-enrolled patients in the United States who had ≥2 claims containing an HIV/AIDS diagnosis from 2006 to 2011 and received an ART prescription from 2007 to 2010. The final population included patients who were ≥18 years old on their index date (ie, date of first ART prescription) and had continuous health plan enrollment for ≥12 months before and after their index date. Treatment characteristics (eg, switching), adverse treatment effects, and health care resource utilization and costs, were evaluated during a 12-month follow-up period. Multivariable models assessed the relationship between ART switching and economic outcomes (ie, costs, number of health care encounters) and adverse treatment effects. RESULTS: A total of 14 590 commercially insured patients met all inclusion criteria and 12% had an ART switch; further, 5744 Medicaid-enrolled patients met all inclusion criteria, and 14% switched treatment. After adjusting for confounders, ART switching was associated with 64% and 36% (P < 0.0001) increases in hospitalizations, 36% and 25% (P < 0.0001) increases in nonpharmacy costs, and 15% and 18% (P < 0.0001) increases in pharmacy costs, among commercially insured and Medicaid-enrolled patients, respectively. ART switching increased the risk of adverse treatment effects, overall and for specific conditions of interest (eg, gastrointestinal intolerance). CONCLUSIONS: This study suggests that ART switching is associated with economic outcomes and certain adverse treatment effects. Efforts to put patients on an optimal ART regimen initially, therefore reducing the need for subsequent switching, may have a positive effect on patients specifically and the health care system in general.