title: Adherence to antiretroviral therapy for HIV in sub-Saharan Africa and Asia: a comparative analysis of two regional cohorts.
abstract: Our understanding of how to achieve optimal long-term adherence to antiretroviral therapy (ART) in settings where the burden of HIV disease is highest remains limited. We compared levels and determinants of adherence over time between HIV-positive persons receiving ART who were enrolled in a bi-regional cohort in sub-Saharan Africa and Asia.
  
  
  
  This multicentre prospective study of adults starting first-line ART assessed patient-reported adherence at follow-up clinic visits using a 30-day visual analogue scale. Determinants of suboptimal adherence (<95%) were assessed for six-month intervals, using generalized estimating equations multivariable logistic regression with multiple imputations. Region of residence (Africa vs. Asia) was assessed as a potential effect modifier.
  
  
  
  Of 13,001 adherence assessments in 3934 participants during the first 24 months of ART, 6.4% (837) were suboptimal, with 7.3% (619/8484) in the African cohort versus 4.8% (218/4517) in the Asian cohort (p< 0.001). In the African cohort, determinants of suboptimal adherence were male sex (odds ratio (OR) 1.27, 95% confidence interval (CI) 1.06-1.53;p= 0.009), younger age (OR 0.8 per 10 year increase; 0.8-0.9;p= 0.003), use of concomitant medication (OR 1.8, 1.0-3.2;p= 0.044) and attending a public facility (OR 1.3, 95% CI 1.1-1.7;p= 0.004). In the Asian cohort, adherence was higher in men who have sex with men (OR for suboptimal adherence 0.6, 95% CI 0.4-0.9;p= 0.029) and lower in injecting drug users (OR for suboptimal adherence 1.6, 95% CI 0.9-2.6;p= 0.075), compared to heterosexuals. Risk of suboptimal adherence decreased with longer ART duration in both regions. Participants in low- and lower-middle-income countries had a higher risk of suboptimal adherence (OR 1.6, 1.3-2.0;p< 0.001), compared to those in upper-middle or high-income countries. Suboptimal adherence was strongly associated with virological failure, in Africa (OR 5.8, 95% CI 4.3-7.7;p< 0.001) and Asia (OR 9.0, 95% CI 5.0-16.2;p< 0.001). Patient-reported adherence barriers among African participants included scheduling demands, drug stockouts, forgetfulness, sickness or adverse events, stigma or depression, regimen complexity and pill burden.
  
  
  
  Psychosocial factors and health system resources may explain regional differences. Adherence-enhancing interventions should address patient-reported barriers tailored to local settings, prioritizing the first years of ART.
authors.affiliation: Amsterdam Institute for Global Health and Development and Department of Global Health, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Rimke
authors.initials: R
authors.lastname: Bijker
authors.affiliation: The Kirby Institute, Biostatistics and Databases Program, UNSW Australia, Sydney, NSW, Australia.
authors.forename: Awachana
authors.initials: A
authors.lastname: Jiamsakul
authors.affiliation: Joint Clinical Research Centre, Kampala, Uganda.
authors.forename: Cissy
authors.initials: C
authors.lastname: Kityo
authors.affiliation: Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Sasisopin
authors.initials: S
authors.lastname: Kiertiburanakul
authors.affiliation: Lusaka Trust Hospital, Lusaka, Zambia.
authors.forename: Margaret
authors.initials: M
authors.lastname: Siwale
authors.affiliation: HIV-NAT/Thai Red Cross AIDS Research Centre, Bangkok, Thailand.
authors.forename: Praphan
authors.initials: P
authors.lastname: Phanuphak
authors.affiliation: College of Medicine, University of Lagos, Lagos, Nigeria.
authors.forename: Sulaimon
authors.initials: S
authors.lastname: Akanmu
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Research Institute for Health Sciences, Chiang Mai, Thailand.
authors.forename: Romanee
authors.initials: R
authors.lastname: Chaiwarith
authors.affiliation: Amsterdam Institute for Global Health and Development and Department of Global Health, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Ferdinand W
authors.initials: FW
authors.lastname: Wit
authors.affiliation: Infectious Disease Unit, Department of Medicine, Hospital Sungai Buloh, Sungai Buloh, Malaysia.
authors.forename: Benedict Lh
authors.initials: BL
authors.lastname: Sim
authors.affiliation: Amsterdam Institute for Global Health and Development and Department of Global Health, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Tamara Sonia
authors.initials: TS
authors.lastname: Boender
authors.affiliation: Research Institute for Tropical Medicine, Manila, Philippines.
authors.forename: Rossana
authors.initials: R
authors.lastname: Ditangco
authors.affiliation: Amsterdam Institute for Global Health and Development and Department of Global Health, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Tobias F
authors.initials: TF
authors.lastname: Rinke De Wit
authors.affiliation: TREAT Asia/amfAR, The Foundation for AIDS Research, Bangkok, Thailand.
authors.forename: Annette H
authors.initials: AH
authors.lastname: Sohn
authors.affiliation: Amsterdam Institute for Global Health and Development and Department of Global Health, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands.|Department of Internal Medicine, Division of Infectious Diseases, Academic Medical Center of the University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Raph L
authors.initials: RL
authors.lastname: Hamers
mesh_terms: D000328:Adult; D017954:Africa South of the Sahara / Q000453:epidemiology; D000554:Ambulatory Care Facilities; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D001208:Asia / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000523:psychology; D020010:Heterosexuality / Q000523:psychology / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D010349:Patient Compliance; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents
keywords: Asia; HIV-1; adherence; antiretroviral therapy (ART); sub-Saharan Africa