Predictors of loss to follow-up among children registered in an HIV prevention mother-to-child transmission cohort study in Pernambuco, Brazil

BACKGROUND: Mother-to-child transmission of HIV (MTCT) is the major form of acquiring the disease among children. The loss to follow-up (LTF) of mothers and their children is a problem that affects the effectiveness of programs for the prevention of mother-to-child transmission (PMTCT). The aim of this study is to identify risk factors associated with the LTF of HIV-exposed children in the state of Pernambuco, Brazil. METHODS: A retrospective cohort study was carried out with 1200 HIV-exposed children born between 2000 and 2009, registered up to the age of 2 months in a public health PMTCT program. Children were considered LTF if they did not return for scheduled visits to monitor infection status. Univariate and multivariate logistic regression analyses were conducted to identify risk factors for LTF. RESULTS: A total of 185 children (15.4%; CI: 95%: 13.4 - 17.4%) met the case definition of LTF before the determination of serological HIV status. Risk factors independently associated with LTF were mother-child pairs who reside in rural and remote areas (OR 1.86; 95% CI: 1.30-2.66) and mothers who use illicit drugs (OR 1.8; 95% CI: 1.08-3.0). Initiation of the PMTCT during pregnancy was a protective factor for LTF (OR 0.69; 95% CI: 0.49-0.96). CONCLUSIONS: The decentralization of support services for HIV-exposed children to other cities in the state seems to be crucial for the accurate monitoring of outcomes. It is also important to introduce additional measures addressing mothers who are drug users so that they remain in the program: an intensive follow-up program that actively searches for absentee mother-child pairs, support from social services and treatment for drug-dependency. The findings of this study highlight the importance of diagnosing mothers as early as possible in order to conduct a more complete follow-up period of the children. Solving the above-mentioned problems is a challenge, which must be overcome so as to improve the quality of PMTCT.