title: Factors related to attrition in a cohort study of HIV in Malawi.
abstract: BACKGROUND
  Longitudinal studies face power reduction due to loss to follow up (LTFU). Bias may also arise because of differences between those who stay in the study and those who are LTFU. We studied factors associated with LTFU in a cohort of HIV seronegative and sera-positive mothers in urban Malawi.
  
  
  OBJECTIVE
  To bridge the existing gaps by examining the factors associated with attrition.
  
  
  METHODS
  Longitudinal study.
  
  
  METHODS
  Queen Elizabeth Central Hospital (QECH) and the Kamuzu Central Hospital in Blantyre, Malawi.
  
  
  METHODS
  One thousand three hundred and fifty three women who attended the prenatal clinic, between October 1989 and October 1990 were recruited as part of a study to determine rates and risk factors of sero-prevalence and sera-conversion of HIV-1 among this cohort.
  
  
  RESULTS
  In this cohort study, 1353 women were enrolled at delivery and 1188 (88%) returned for the first follow-up visit at three months post-partum. Of those who returned, 177 (15%) were subsequently lost during the remaining months of follow-up. The main predictors of LTFU were younger maternal age, lower educational level of the father, HIV infection of the mother, lower birth weight of the index child and mother not being married.
  
  
  CONCLUSIONS
  Researchers planning studies in developing countries should consider the impact of lower education and poorer infant health on study retention in developing countries.
authors.affiliation: Department of Epidemiology, Johns Hopkins University Bloomberg School of Hygiene and Public Health, Baltimore, MD, USA.
authors.forename: O O
authors.initials: OO
authors.lastname: Obasanjo
authors.forename: N
authors.initials: N
authors.lastname: Kumwenda
mesh_terms: D000328:Adult; D015982:Bias; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000453:epidemiology / Q000635:transmission* / Q000821:virology; D015497:HIV-1; D006801:Humans; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008295:Malawi / Q000453:epidemiology; D010352:Patient Dropouts / Q000706:statistics & numerical data*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology* / Q000821:virology; D015995:Prevalence; D012959:Socioeconomic Factors; D055815:Young Adult