title: A clinical prediction score in addition to WHO criteria for anti-retroviral treatment failure in resource-limited settings--experience from Lesotho.
abstract: OBJECTIVE
  To assess the positive predictive value (PPV) of a clinical score for viral failure among patients fulfilling the WHO-criteria for anti-retroviral treatment (ART) failure in rural Lesotho.
  
  
  METHODS
  Patients fulfilling clinical and/or immunological WHO failure-criteria were enrolled. The score includes the following predictors: Prior ART exposure (1 point), CD4-count below baseline (1), 25% and 50% drop from peak CD4-count (1 and 2), hemoglobin drop≥1 g/dL (1), CD4 count<100/µl after 12 months (1), new onset papular pruritic eruption (1), and adherence<95% (3). A nurse assessed the score the day blood was drawn for viral load (VL). Reported confidence intervals (CI) were calculated using Wilsons method.
  
  
  RESULTS
  Among 1'131 patients on ART ≥ 6 months, 134 (11.8%) had immunological and/or clinical failure, 104 (78%) had blood drawn (13 died, 10 lost to follow-up, 7 did not show up). From 92 (88%) a result could be obtained (2 samples hemolysed, 10 lost). Out of these 92 patients 47 (51%) had viral failure (≥ 5000 copies), 27 (29%) viral suppression (<40) and 18 (20%) intermediate viremia (40-4999). Overall, 20 (22%) had a score ≥ 5. A score ≥ 5 had a PPV of 100% to detect a VL>40 copies (95%CI: 84-100), and of 90% to detect a VL ≥ 5000 copies (70-97). Within the score, adherence<95%, CD4-count<100/µl and papular pruritic eruption were the strongest single predictors. Among 47 patients failing, 8 (17%) died before or within 4 weeks after being switched. Overall mortality was 4 (20%) among those with score ≥ 5 and 4 (5%) if score<5 (OR 4.3; 95%CI: 0.96-18.84, p = 0.057).
  
  
  CONCLUSIONS
  A score ≥ 5 among patients fulfilling WHO-criteria had a PPV of 100% for a detectable VL and 90% for viral failure. In settings without regular access to VL-testing, this PPV may be considered high enough to switch this patient-group to second-line treatment without confirmatory VL-test.
authors.affiliation: SolidarMed Lesotho, Seboche Hospital, Botha-Bothe, Lesotho. niklaus.labhardt@gmail.com
authors.forename: Niklaus Daniel
authors.initials: ND
authors.lastname: Labhardt
authors.forename: Thabo
authors.initials: T
authors.lastname: Lejone
authors.forename: Matse'liso
authors.initials: M
authors.lastname: Setoko
authors.forename: Matalenyane
authors.initials: M
authors.lastname: Poka
authors.forename: Jochen
authors.initials: J
authors.lastname: Ehmer
authors.forename: Karolin
authors.initials: K
authors.lastname: Pfeiffer
authors.forename: Patrice Zinga
authors.initials: PZ
authors.lastname: Kiuvu
authors.forename: Lutgarde
authors.initials: L
authors.lastname: Lynen
mesh_terms: D000293:Adolescent; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D015704:CD4 Antigens / Q000097:blood*; D018791:CD4 Lymphocyte Count / Q000379:methods; D002648:Child; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy; D015497:HIV-1 / Q000302:isolation & purification; D006295:Health Resources; D006801:Humans; D007927:Lesotho; D008297:Male; D017211:Treatment Failure; D019562:Viral Load; D014944:World Health Organization
chemical_list: D019380:Anti-HIV Agents; D015704:CD4 Antigens