Identifying Causes of Antiretroviral Treatment Failure in HIV-Infected Patients

Background:

Despite significant advances in antiretroviral therapy (ART) for HIV, not all individuals are able to achieve virologic suppression. This retrospective study identifies variables associated with persistent viremia in an academic practice.

Methods:

We included HIV-infected patients with a viral load of >200 copies/mL over a period from 2013–2014 alongside controls matched 1:1 via a propensity score utilizing age at diagnosis, era of diagnosis, gender, and initial CD4 count. We collected data on multiple variables including medications, adherence, genotype, comorbidities, hospitalizations, and insurance status. Conditional logistic regression was used for unadjusted/adjusted analyses. The final multivariable model was built using backwards elimination via the likelihood ratio test. Interactions were tested.

Results:

We included 66 viremic cases, 66 matched controls. The average age was 38.4 ± 11.2 years; 74% were male, 52% were white race, and 12%/21% were on combination ART at the study start/end, respectively. On unadjusted analysis, fewer viremic patients were on ART for all 12 months (odds ratio [OR] 0.33, 95% confidence interval [95CI] 0.13–0.83, P =.018). Fewer were white (OR 0.49, 95CI 0.24–1.01, P =.053). Hospitalization (OR 10.0, 95CI 1.28–78.10, P =.028), underinsurance (OR 5.87, 95CI 1.30–26.60, P= .022), and conflicting personal beliefs about their disease (OR 5.50, 95CI 1.22–24.80, P=.027) were more common. Hospitalization was associated with viremia, receipt of ART at the start of the study was protective (Table 1). Notably, in the final model, an interaction was observed between psychiatric illness and the number of clinic visits during the study period, with psychiatric illness increasing the odds of viremia in patients who had four or more visits (OR 1.63/6.64 with four/five clinic visits, respectively).

Table 1. Multivariable model of persistent viremia in HIV patients
Variable	OR	95CI	P
On ART at study start	0.03	<0.01–0.31	.003
Psychiatric illness	0.01	<0.01–0.22	.005
Hospitalization	65.9	3.4–1280	.006
Clinic visits during study period (n)	0.99	0.68–1.43	.949
Psychiatric illness & clinic visits during study period (interaction)	4.07	1.25–13.3	.02

Conclusion:

This study provides insight into factors predictive of viremia in HIV-infected patients in the modern era. The effects of improved management of psychiatric illness on viremia warrants further study.