title: Loss to follow-up among infants in a study of isoniazid prophylaxis (P1041) in South Africa.
abstract: OBJECTIVE
  To assess risk factors for loss to follow-up (LFU) from the IMPAACT P1041 study, an isoniazid (INH) prophylaxis study conducted in southern Africa.
  
  
  METHODS
  Infants in two cohorts, human immunodeficiency virus-infected (HIV+) and HIV-exposed but non-infected (HIV-),  were randomized to INH or placebo for 96 weeks. LFU was evaluated at week 96.
  
  
  RESULTS
  Of 1351 infants, 12.9% were LFU (10.4% HIV+, 14.7% HIV-); 65% of the HIV+ cohort was asymptomatic. Among HIV+ infants, large household size (>6 vs. <4 members, P = 0.035) and presence  of an elder (≥55 years, P = 0.05) were associated with better retention. Although attenuated in adjusted analysis, these associations held among HIV- infants. Among HIV- infants, having a younger mother increased the risk (P = 0.008) and maternal history of TB  reduced the risk of LFU, the latter by nearly 70% (P = 0.048 univariate, 0.09 adjusted). LFU was largely due to inability to contact the participant (58% HIV+, 30% HIV-), and inability to attend the clinic and withdrawal of consent (HIV-).
  
  
  CONCLUSIONS
  Household support  was an important factor in participant retention, particularly for the non-HIV-infected cohort, as young maternal age was a risk factor for LFU. Retaining study participants from this mobile population can be challenging and may warrant additional support.
authors.affiliation: State University of New York at Stony Brook, Stony Brook, NY 11794-8111, USA. christy.beneri@stonybrook.edu
authors.forename: C A
authors.initials: CA
authors.lastname: Beneri
authors.forename: B
authors.initials: B
authors.lastname: Zeldow
authors.forename: S
authors.initials: S
authors.lastname: Nachman
authors.forename: M
authors.initials: M
authors.lastname: Van der Linde
authors.forename: E
authors.initials: E
authors.lastname: Pillay
authors.forename: S
authors.initials: S
authors.lastname: Dittmer
authors.forename: S
authors.initials: S
authors.lastname: Kim
authors.forename: P
authors.initials: P
authors.lastname: Jean-Philippe
authors.forename: J
authors.initials: J
authors.lastname: Coetzee
authors.forename: R
authors.initials: R
authors.lastname: Bobat
authors.forename: E
authors.initials: E
authors.lastname: Hawkins
authors.forename: A
authors.initials: A
authors.lastname: Violari
mesh_terms: D000995:Antitubercular Agents / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000150:complications; D006801:Humans; D007223:Infant; D007538:Isoniazid / Q000627:therapeutic use*; D008297:Male; D010349:Patient Compliance / Q000706:statistics & numerical data*; D012307:Risk Factors; D013019:South Africa; D014376:Tuberculosis / Q000209:etiology / Q000517:prevention & control*
chemical_list: D000995:Antitubercular Agents; D007538:Isoniazid