Dose-related and contextual aspects of suboptimal adherence to antiretroviral therapy among persons living with HIV in Western Europe

Background: The daily oral dosing requirement for antiretroviral therapy (ART) may be challenging for some people living with HIV (PLWHIV) with comorbid conditions, confidentiality concerns or pill fatigue. We investigated suboptimal adherence from the perspective of PLWHIV and HIV physicians. Methods: PLWHIV on ART (n = 688) and HIV physicians (n = 120) were surveyed during 2019 in France, Germany, Italy and the UK. Suboptimal adherence was a report the participant missed taking their dose as prescribed 'Sometimes'/'Often'/'Very often'. Physicians' interest in offering a hypothetical long-acting HIV regimen for suboptimally adherent patients was assessed. Descriptive and multivariable analyses were performed (P < 0.05). Results: Of PLWHIV, 23.8% (164/688) reported suboptimal adherence vs. providers' estimated prevalence of 33.6% (SD = 28.8). PLWHIV-reported prevalence of specific suboptimal adherence behaviors were: mistimed dose [16.1% (111/688)]; missed a dose [15.7% (108/688)]; dosed under wrong conditions [e.g. food restrictions, 10.5% (72/688)] and overdosed [3.3% (23/688)]. Odds of suboptimal adherence were higher among those with vs. without a report of the following: dysphagia (AOR = 3.61, 95% CI = 2.28-5.74), stress/anxiety because of their daily dosing schedule (AOR = 3.09, 95% CI = 1.97-4.85), gastrointestinal side effects (AOR = 2.09, 95% CI = 1.39-3.15), neurocognitive/mental health conditions (AOR = 1.88, 95% CI = 1.30-2.72) or hiding their HIV medication (AOR = 1.51, 95% CI = 1.04-2.19). Of providers, 84.2% indicated they Definitely/Probably will offer a hypothetical long-acting HIV regimen 'for patients who have suboptimal levels of adherence to daily oral therapy (50-90%) for non-medical reasons'. Conclusions: Dysphagia, stressful daily oral dosing schedule, gastrointestinal side effects, neurocognitive/mental health conditions and confidentiality concerns were associated with suboptimal adherence in our study. Adherence support and alternative regimens, such as long-acting antiretroviral therapies, could help address these challenges.