<p>Adherence to HIV treatment regimens: systematic literature review and meta-analysis</p>

Abstract

Background Antiretroviral therapy (ART), when taken consistently, reduces morbidity and mortality associated with human immunodeficiency virus and viral transmission. Suboptimal treatment adherence is associated with regimen complexity and high tablet burden. Single-tablet regimens (STRs) provide a complete treatment regimen in a single tablet. This study examined the relationship between STRs (vs multiple-tablet regimens [MTRs]), treatment adherence, and viral suppression. Methods A systematic review was conducted to identify studies investigating at least one of the following: (1) STR/MTR use and adherence; (2) levels of adherence and viral suppression; and (3) STR/MTR use and viral suppression. Meta-analysis was performed to assess the relationship between STR vs MTR use and adherence in observational settings at ≥95% and ≥90% adherence thresholds. Results In total, 29 studies were identified across the three objectives; two studies were relevant for all objectives. STRs were associated with higher treatment adherence than MTRs in 10/11 observational studies: a 63% greater likelihood of achieving ≥95% adherence (95% CI=1.52–1.74; P <0.001) and a 43% increase in the likelihood of achieving ≥90% adherence (95% CI=1.21–1.69; P <0.001). Higher adherence rates were associated with higher levels of viral suppression in 13/18 studies. Results were mixed in five studies investigating the association between STR or MTR use and viral suppression. Conclusion Although the direct effect of STRs vs MTRs on viral suppression remains unclear, this study provided a quantitative estimate of the relationship between STRs and ART adherence, demonstrating that STRs are associated with significantly higher ART adherence levels at 95% and 90% thresholds. Findings from the systematic review showed that improved adherence results in an increased likelihood of achieving viral suppression in observational settings. Future research should utilize similar measures for adherence and evaluate viral suppression to improve assessment of the relationship between pill burden, adherence, and viral suppression.

Real-world adherence and persistence for newly-prescribed HIV treatment: single versus multiple tablet regimen comparison among US medicaid beneficiaries

“…Outcome measures, including adherence and persistence during the follow-up period were measured. In HIV, a high level of adherence to ART is required for viral suppression [13]. However, thresholds for categorizing "adherent" versus "non-adherent" differ across studies (e.g.…”

“…STRs are single-dose units administered once-daily, whereas multi-tablet regimens (MTRs) require multiple dosing units per day [4]. STRs may improve adherence, thus resulting in greater efficacy, reduced risk of virologic failure, and prevention of the emergence of drug resistance [13,14]. The decision to prescribe STRs vs MTRs is based to a large extent on patient and clinician preference as well as, in some instances, medication cost and positioning of products on payer formularies [15,16].…”

“…Prior research suggests that adherence and persistence may be higher among patients treated with STRs compared with those treated with MTRs [13,19]. However, with the advent of new treatment options with greater effectiveness and tolerability, the extent to which adherence and persistence varies between and within STRs and MTRs has not been fully investigated.…”

Comparing self-reported medication adherence measures with hair antiretroviral concentration among people living with HIV in Guangxi, China

“…However, despite the increased availability of antiretroviral medications, HIV-related morbidity, mortality, and new infection rate continually increased over the years in China from 2004 to 2016 [1]. Both clinical trials and cohort studies have shown that the effectiveness of antiretroviral medications is highly dependent on adherence [2][3][4]. Suboptimal adherence severely undercuts antiretroviral effectiveness and places PLHIV at risk for virologic failure, increases the risk of onward HIV transmission, and limits the impact of HIV treatment resources [5,6].…”

Retention and predictors of attrition among patients who started antiretroviral therapy in Zimbabwe’s National Antiretroviral Therapy Programme between 2012 and 2015

“…PLHIV on ART who are not retained in care are at increased risk of developing drug resistance and dying [4]. Based on a systematic review of several studies that have been conducted in low resource settings, key predictors of high attrition include patients with advanced HIV-disease progression [marked by body mass index (BMI) <18 kg/m 2 , baseline CD4 counts <200 cells/mL, World Health Organisation (WHO) Stage - III and IV, poorer level of functionality], male sex, younger age and having lower levels of education [5].…”