November 1, 2013
HIV-infected patients may be significantly less likely to adhere to the medications they take for their comorbid conditions than to their HIV antiretrovirals, according to research presented at IDWeek 2013. The findings shed light on the increasing importance of clinicians ensuring that, as they continue to provide HIV care for their patients, they also help those patients effectively manage the health issues they commonly experience alongside their HIV infection, such as dyslipidemia and cardiovascular disease.
Researchers from Case Western Reserve University and the Louis Stokes Cleveland VA Medical Center conducted a retrospective chart review of 171 HIV-infected patients who received care through the Louis Stokes medical center in 2011 and 2012. During the study period, all patients were continuously prescribed HIV antiretroviral therapy and non-HIV medications.
This was an almost entirely male (95%) and predominantly black (57%) study cohort. The mean age at baseline was roughly 55 years. Despite relatively high rates of mental health issues (45% of the cohort had a history of depression, 22% had a history of substance abuse and 18% had a history of alcohol abuse), most patients had a baseline CD4+ cell count over 200 cells/mm3 (86%) and the vast majority had a baseline viral load below 75 copies/mL (78%). This is not particularly a surprise among populations of patients who receive care at Veterans Affairs clinics, which tend to report better engagement in care.
The 171 patients were prescribed a total of 458 antiretrovirals and 667 non-antiretroviral medications during the study period. Most of the antiretrovirals prescribed were typical first-line agents, predominantly efavirenz/tenofovir/emtricitabine (Atripla), tenofovir/emtricitabine (Truvada), atazanavir (Reyataz) and ritonavir (Norvir). The non-antiretroviral medications commonly fell into one of four classes: prescription vitamins (especially multivitamins), antihypertensives (predominantly lisinopril and hydrochlorothiazide, taken either separately or concurrently), gastrointestinal agents (mainly omeprazole) and antidepressants (citalopram, sertraline or mirtazapine).
Adherence to medications was calculated using a "proportion of days covered" (PDC) measurement, which is based on an examination of the patients' medication supply and refill dates compared to prescription release dates. A paired samples t-test was used to compare adherence levels between the two types of medications.
The researchers found that study patients' overall mean PDC was 85.8% for antiretrovirals, compared to a notably lower 77.0% for non-antiretrovirals (P < .001), a difference that was equivalent to 32.1 additional days of missed non-antiretroviral coverage over a 365-day period. In a multiple linear regression analysis, no correlation with PDC difference was found by age, copayment exemption status or having a history of alcohol abuse, depression or substance abuse.
Mean PDC appeared to vary by drug class as well as individual drug, though no numbers regarding statistical significance were provided (and the overall number of patients on each drug was relatively small). PDC appeared similarly high among most antiretrovirals, with most hovering in the 80% to 90% range. Among non-antiretrovirals, PDC appeared highest for the hypertensives (with ranges from 85% to 92%) and lower for antidepressants (68% to 82%), gastrointestinal agents (70% to 74%) and vitamins (64% to 76%).
As the attention of HIV care providers turns ever-more often to the management of comorbid conditions (including cardiovascular care, mental health and digestive/gastrointestinal care) in our increasingly aging HIV-infected populations, study results such as these highlight the need to remain vigilant that patients are tending to all aspects of their health. "Patients who are otherwise adherent to their ART are less adherent with their non-ART medications. Interventions to improve medication adherence should also include non-ART medications in addition to ART," the researchers concluded.
Myles Helfand is the editorial director of TheBody.com and TheBodyPRO.com.
Follow Myles on Twitter: @MylesatTheBody.