Retrospective analysis of adherence to HIV treatment and healthcare utilization in a commercially insured population

Aims: Single-tablet regimens (STRs) can improve antiretroviral therapy (ART) adherence; however, the relationship between long-term adherence and patient healthcare resource utilization (HRU) is unclear. The objective of this study was to assess long-term ART adherence among people living with HIV (PLHIV) using STRs and multi-tablet regimens (MTRs) and compare HRU over time by adherence.

Materials and methods: This retrospective study analyzed medical and pharmacy claims (Optum Clinformatics Data Mart Database). Included PLHIV were aged ≥18 years, had ≥1 medical claim with an HIV diagnosis, and had pharmacy claims for a complete STR or MTR. Adherence was analyzed as the proportion of days covered (PDC), stratified as ≥95%, very high; 90-95%, high; 80-90%, moderate; <80%, low. Cumulative all-cause and HIV-related HRU were calculated across 4 years. Among PLHIV with ≥4-year follow-up, HRU was assessed by adherence.

Results: Among 15,153 PLHIV included, 63% achieved PDC ≥90% during Year 1. Among the subgroup of PLHIV with ≥4-year follow-up (N = 3,818), the proportion maintaining PDC ≥90% fell from 67% in Year 1 to 54% by Year 4. The difference from Years 1 to 4 in the proportion of PLHIV with PDC ≥90% was 13% and 17% in the STR and MTR groups, respectively. Cumulative HRU across the 4-year follow-up was higher in PLHIV with low vs high adherence (27% with low adherence had ≥1 emergency room visit vs 17% for very high, p < .0001; 15% with low adherence had ≥1 inpatient stay vs 7% for very high, p < .0001).

Conclusions: ART adherence showed room for improvement, particularly over the long term. PLHIV receiving STRs exhibited higher adherence vs those receiving MTRs; this difference increased over time. The proportion of PLHIV with higher HRU was significantly higher among those with lower adherence and became greater over time. Interventions and alternative therapies to improve adherence among PLHIV should be explored.