title: Lost to follow-up among pregnant women in a multi-site community based maternal and newborn health registry: a prospective study.
abstract: BACKGROUND
  It is important when conducting epidemiologic studies to closely monitor lost to follow up (LTFU) rates. A high LTFU rate may lead to incomplete study results which in turn can introduce bias to the trial or study, threatening the validity of the findings. There is scarce information on LTFU in prospective community-based perinatal epidemiological studies. This paper reports the rates of LTFU, describes socio-demographic characteristics, and pregnancy/delivery outcomes of mothers LTFU in a large community-based pregnancy registry study.
  
  
  METHODS
  Data were from a prospective, population-based observational study of the Global Network for Women's and Children's Health Research Maternal Newborn Health Registry (MNHR). This is a multi-centre, international study in which pregnant women were enrolled in mid-pregnancy, followed through parturition and 42 days post-delivery. Risk for LTFU was calculated within a 95%CI.
  
  
  RESULTS
  A total of 282,626 subjects were enrolled in this study, of which 4,893 were lost to follow-up. Overall, there was a 1.7% LTFU to follow up rate. Factors associated with a higher LTFU included mothers who did not know their last menstrual period (RR 2.2, 95% CI 1.1, 4.4), maternal age of < 20 years (RR 1.2, 95% CI 1.1, 1.3), women with no formal education (RR 1.2, 95% CI 1.1, 1.4), and attending a government clinic for antenatal care (RR 2.0, 95% CI 1.4, 2.8). Post-natal factors associated with a higher LTFU rate included a newborn with feeding problems (RR 1.6, 94% CI 1.2, 2.2).
  
  
  CONCLUSIONS
  The LTFU rate in this community-based registry was low (1.7%). Maternal age, maternal level of education, pregnancy status at enrollment and using a government facility for ANC are factors associated with being LTFU. Strategies to ensure representation and high retention in community studies are important to informing progress toward public health goals.
  
  
  BACKGROUND
  Registration at the Clinicaltrials.gov (ID# NCT01073475).
authors.forename: Irene
authors.initials: I
authors.lastname: Marete
authors.forename: Constance
authors.initials: C
authors.lastname: Tenge
authors.forename: Carolyne
authors.initials: C
authors.lastname: Chemweno
authors.forename: Sherri
authors.initials: S
authors.lastname: Bucher
authors.forename: Omrana
authors.initials: O
authors.lastname: Pasha
authors.forename: Umesh Y
authors.initials: UY
authors.lastname: Ramadurg
authors.forename: Shivanand C
authors.initials: SC
authors.lastname: Mastiholi
authors.forename: Melody
authors.initials: M
authors.lastname: Chiwila
authors.forename: Archana
authors.initials: A
authors.lastname: Patel
authors.forename: Fernando
authors.initials: F
authors.lastname: Althabe
authors.forename: Ana
authors.initials: A
authors.lastname: Garces
authors.forename: Janet L
authors.initials: JL
authors.lastname: Moore
authors.forename: Edward A
authors.initials: EA
authors.lastname: Liechty
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Derman
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Hibberd
authors.forename: K
authors.initials: K
authors.lastname: Hambidge
authors.forename: Robert L
authors.initials: RL
authors.lastname: Goldenberg
authors.forename: Waldemar A
authors.initials: WA
authors.lastname: Carlo
authors.forename: Marion
authors.initials: M
authors.lastname: Koso-Thomas
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: McClure
authors.forename: Fabian
authors.initials: F
authors.lastname: Esamai
mesh_terms: D000293:Adolescent; D000328:Adult; D036861:Delivery, Obstetric / Q000379:methods; D004522:Educational Status; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D000068104:Infant Health / Q000706:statistics & numerical data*; D007231:Infant, Newborn; D059012:Lost to Follow-Up; D008423:Maternal Age; D000068097:Maternal Health / Q000706:statistics & numerical data*; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology*; D011295:Prenatal Care; D011446:Prospective Studies; D012042:Registries / Q000706:statistics & numerical data*; D055815:Young Adult