Predictors of Virologic Success in an Older ART Naïve HIV Population

Background:

Older HIV+ patients are more likely to be balancing HIV treatment with the challenges of aging (senescence, comorbidities, polypharmacy) than younger patients. Our objective was to identify and compare predictors of virologic suppression in two age defined populations (26-49, vs 50 +).

Methods:

HIV+ individuals initiating ART between 1/1/2007 and 3/31/2015 were identified from OPERA, a collaboration of HIV caregivers from 79 clinics in 15 states. Virologic success was defined as HIV RNA <50 copies/mL. Patients were followed from ART start to the first of: an HIV RNA <50 copies/mL, discontinuation of regimen, loss to follow up, or death. Predictors of suppression were evaluated using Cox proportional hazards models.

Results:

The bulk of ART naïve patients were aged 26-49 (n=6,139) vs. aged 50+ (n=1,174) since patients aged 13-25 were excluded from the analysis. Older patients were largely in their 50s (54.1 IQR [51.9, 58.1]); and as compared to middle-aged patients (aged 36.4 [30.6, 42.8]) were more likely to be female, African American, to have substantially more comorbidities (CVD, cancer, endocrine, liver, bone, renal, neuropathy, and hypertension) and larger pill burden.  Older patients were less likely (vs middle aged) to be Hispanic, MSM, or be prescribed an NNRTI or INSTI containing regimen. At baseline, older patients had higher VL, lower CD4 counts, and were more likely to have AIDS. Syphilis was the sole comorbidity with significantly higher prevalence in the 26-49 group. Figure 1 depicts the predictors associated with suppression. The strongest predictor of suppression in 26-49 (HR 2.3 CI 2.0, 2.6) and 50+ (HR 2.0 CI 1.6, 2.4) age groups was initiating on an INSTI based regimen. Late initiators (higher VL, lower CD4) had significantly lower probability of suppression. 

Conclusion:

Older patients share several highly predictive factors of virologic success with their middle-aged counterparts including type of ART initiated despite presenting with more advance disease (higher VL, AIDS) and greater co-morbidity.  HCV and substance abuse were negative prognosticators though not significant in the older population. These data reinforce the importance of early diagnosis and access to care for older HIV infected individuals.