Risk Factors, Health Care Resource Utilization, and Costs Associated with Nonadherence to Antiretrovirals in...

Adherence to antiretrovirals (ARVs) is critical to achieving durable virologic suppression.

To investigate risk factors of poor adherence and the effect of suboptimal adherence on health care resource utilization (HCRU) and costs in Medicaid patients.

A retrospective longitudinal study was conducted using Medicaid data. Adults (aged ≥ 18 years) with human immunodeficiency virus (HIV)-1 initiating selected ARVs (index date) were identified. Adherence was measured using medication possession ratio (MPR) and proportion of days covered (PDC) at 6 and 12 months post-index. Risk factors of poor adherence (PDC < 80%) were assessed using a logistic regression. HCRU and costs were compared between suboptimal (80% ≤ PDC < 95%) and optimal (PDC ≥ 95%) adherence groups using Poisson and ordinary least square models, respectively.

In total, 3,477 patients were identified. Using MPR, 1,282 (39.0%) of the evaluable patients had poor adherence; 667 (20.2%) had suboptimal adherence; and 1,342 (40.8%) had optimal adherence versus 1,342 (51.1%), 509 (19.0%), and 804 (30.0%), respectively, using PDC at 6 months. PDC at 12 months was even lower. Younger age (OR = 1.58; 95% CI = 1.18-2.11; P = 0.002), noncapitated coverage (OR = 1.40; 95% CI = 1.16-1.69; P < 0.001), dual Medicaid/Medicare coverage (OR = 5.98; 95% CI = 4.39-8.16; P < 0.001), no baseline ARV treatment (OR = 1.98; 95% CI = 1.62-2.41; P < 0.001), and baseline asymptomatic HIV (OR = 1.37; 95% CI = 1.13-1.68; P = 0.002) were associated with higher risk of poor adherence. Suboptimal adherence patients had higher total number of days spent in a hospital (incidence rate ratio [IRR] = 1.62; 95% CI = 1.13-2.19; P = 0.008), total number of long-term care admissions (IRR = 3.11; 95% CI = 1.26-7.39; P = 0.008), total medical costs (mean monthly cost difference = $339; 95% CI = $153-$536; P < 0.001), and inpatient costs (mean monthly cost difference = $259; 95% CI = $122-$418; P < 0.001) compared with patients with optimal adherence.

Nonadherence to ARVs was observed in 60%-80% of Medicaid patients, depending on the adherence measure used, and was associated with incremental HCRU and costs. Age, insurance type and coverage, previous ARV treatment, and HIV symptoms were predictors of adherence. Treatment options that enhance adherence and prevent developing virologic failure with drug resistance should be considered for HIV patients.

This study was supported by Janssen Scientific Affairs, which was involved in the study design, data collection, data analysis, manuscript preparation, and publication decisions. Emond, Lafeuille, Romdhani, and Lefebvre are employees of Analysis Group, a consulting company that received research grants from Janssen Scientific Affairs to conduct this study. Dunn, Woodruff, Pesa, and Tandon are current employees and stockholders of Johnson & Johnson, owner of Janssen Scientific Affairs. Jiao was an employee of Janssen at the time of the study. Emond has received grants from Novartis, Regeneron, Aegerion, Lundbeck, Bristol-Myers Squibb, Bayer, Millennium, Allergan, AbbVie, and GlaxoSmithKline unrelated to this study. Part of the material in this study was presented at the Academy of Managed Care Pharmacy 2017 Annual Meeting; March 27-30, 2017; Denver, CO, and at the 9th International AIDS Society Conference; July 23-26, 2017; Paris, France.