Is the pill count or polyactive substance count a better estimate of polypharmacy in people living with HIV/AIDS?

Introduction: People with HIV/AIDS (PLWHA) now live longer due to the advent of antiretroviral therapy, but consequently are at an increased risk of age-related comorbidities. Increasing comorbidities have resulted in polypharmacy in PLWHA. Most studies define polypharmacy as the use of five or more medications simultaneously, but researchers have suggested that a definition based on the number of pharmacologically active ingredients (polyactive substances) may be a better indicator of polypharmacy. Typically, drugs for HIV/AIDS and other chronic diseases are combined into single doses to maximize adherence. Therefore, most pills used by PLWHA are a combination of two or more polyactive substances. However, due to limited literature, it is not clear by how much polypharmacy (defined by pill count) differs from that defined by polyactive substances. Objective: To compare polypharmacy in PLWHA by determining the difference between the pill count and the number of polyactive substances. Method: Medication records of 765 HIV patients from a study were obtained. Polypharmacy was defined as the use of five or more medications. Polyactive substance use was defined as the use of five or more pharmacologically active ingredients in medications. Result: The prevalence of polypharmacy using pill count at baseline was 78.3% at baseline, while the prevalence of polyactive substances was 92.16%. A paired T-test showed a mean difference of 2.15 with a standard deviation of 1.32 (p-value < 0.001) between polyactive substances and pill count. Conclusion: Among HIV patients, pill count underestimates the prevalence of polypharmacy compared to polyactive substance count.