Polypharmacy is commonly defined as treatment with 5 or more chronic medications. A number of studies have associated polypharmacy with poorer adherence and more adverse drug events, as well as increased costs, hospitalizations, length of stay, morbidity, and mortality. In HIV-infected populations, there are few data on the effects of polypharmacy. At ID Week 2013, a presentation from the Veterans Aging Cohort Study (VACS) attempted to describe the patterns of and factors associated with polypharmacy in HIV-infected patients and to determine the association between polypharmacy and mortality.
In this cross-sectional analysis of Veterans Administration electronic medical and pharmacy records from October 2009 to September 2010, HIV-infected patients were matched 1:2 with HIV-uninfected controls. Medications were included if they were prescribed for 90 days or more (allowing for a 30-day gap) for patients who were actively in care (defined as ≥1 provider visit in the time period). Analysis included both descriptive statistics and multivariable models.
The study cohort comprised 16,989 HIV-infected patients receiving antiretroviral therapy and 47,613 HIV-uninfected patients. Their mean age was 56 years and 40% were Caucasian; the HIV-infected subjects had a median of CD4 count of 322 cells/µL and a median viral load of 4,321 copies/mL. Of note, the VACS score was 26 in the HIV-infected patients compared with 12 in the control group. HIV-infected patients had comorbidities that closely mirrored those who were uninfected but were prescribed 0.5 fewer medications on average. Men and nonwhite patients received fewer medications as well. Sicker patients and those with comorbidities received more medications, as expected. Of note, the authors stated that specific conditions themselves drove medication count rather than disease severity.
For both HIV-infected patients and controls, mortality was noted with a higher number of medications, particularly in those who took ≥5 medications. For HIV-infected patients receiving 3-4 medications, 5-7 medications, and 8 or more medications, hazard ratios for mortality were approximately 1.4, 2.1, and 2.1, respectively, while for controls they were 1.4, 1.5, and 1.9, respectively.
The authors concluded that polypharmacy is associated with increased mortality risk. Although they could not completely control for the association of increased illness with increased number of prescribed medications, their research serves as a starting point for additional investigations into HIV and polypharmacy, and it continues the discussion on how best to reduce polypharmacy.