Loss to follow-up among infants in a study of isoniazid prophylaxis (P1041) in South Africa

Int J Tuberc Lung Dis. 2013 Jan;17(1):32-8. doi: 10.5588/ijtld.12.0282.


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.

Design: 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.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Antitubercular Agents / therapeutic use*
  • Double-Blind Method
  • Female
  • Follow-Up Studies
  • HIV Infections / complications
  • Humans
  • Infant
  • Isoniazid / therapeutic use*
  • Male
  • Patient Compliance / statistics & numerical data*
  • Risk Factors
  • South Africa
  • Tuberculosis / etiology
  • Tuberculosis / prevention & control*


  • Antitubercular Agents
  • Isoniazid