title: Which method of adherence measurement is most suitable for daily use to predict virological failure among immigrant and non-immigrant HIV-1 infected patients?
abstract: In industrialized countries, virological failure occurs more often among HIV-infected immigrant patients. Non-adherence is the most credible explanation. We compared adherence of immigrant patients with that of non-immigrant patients in the Netherlands, and investigated which method of adherence measurement is most suitable for daily use to predict virological treatment failure: testing knowledge of the current regimen, a quantitative adherence interview, pharmacy prescription refill ratio (dispensed medication divided by prescribed medication, DM/PM), and plasma drug levels. Included were 61 immigrants and 81 non-immigrants. Virological failure did occur more often in immigrants than in non-immigrants (19.7% (12/61) versus 8.6% (7/81), p=0.056), especially among previously naive patients (19.6% (11/56) versus 0% (0/54), p<0.01). There were no differences between both groups on any of the four adherence measures. Virological failure was associated with reporting stopping medication when not feeling well (OR=12, 95%CI=1.9-77.7, p=0.02), and, among naive patients, also with a DM/PM < 0.85 (Odds Ratio=5.1, 95%Confidence Interval=1.2-22.3, p=0.03). Although our study confirmed a much higher virological failure rate among immigrants, we were unable to identify clear differences in adherence between immigrants and non-immigrant patient, although virological failure was associated with stopping medication when not feeling well and a low DM/PM. Unstructured treatment interruptions are a likely explanation of the findings. Interventions should be aimed at preventing patients to stop medication. A DM/PM below 0.85 can be indicative for patients who did stop medication and are at risk for virological failure.
authors.affiliation: Department of Internal Medicine, Division of Infectious Diseases, Tropical Medicine and AIDS, and Centre for Infection and Immunity Amsterdam, Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands. f.j.nellen@amc.uva.nl
authors.forename: Jeannine F J B
authors.initials: JF
authors.lastname: Nellen
authors.forename: Pythia T
authors.initials: PT
authors.lastname: Nieuwkerk
authors.forename: David M
authors.initials: DM
authors.lastname: Burger
authors.forename: Mirte
authors.initials: M
authors.lastname: Wibaut
authors.forename: Luuk A
authors.initials: LA
authors.lastname: Gras
authors.forename: Jan M
authors.initials: JM
authors.lastname: Prins
mesh_terms: D000328:Adult; D017954:Africa South of the Sahara / Q000208:ethnology; D019380:Anti-HIV Agents / Q000097:blood / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active; D054242:Emigrants and Immigrants / Q000706:statistics & numerical data*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000208:ethnology / Q000821:virology; D015497:HIV-1; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D055118:Medication Adherence / Q000208:ethnology; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D009427:Netherlands Antilles / Q000208:ethnology; D012367:RNA, Viral / Q000097:blood; D013532:Suriname / Q000208:ethnology; D017211:Treatment Failure; D016903:Drug Monitoring
chemical_list: D019380:Anti-HIV Agents; D012367:RNA, Viral