title: Determinants of participation in a longitudinal two-stage study of the health consequences of the Chornobyl nuclear power plant accident.
abstract: BACKGROUND
  The determinants of participation in long-term follow-up studies of disasters have rarely been delineated. Even less is known from studies of events that occurred in eastern Europe. We examined the factors associated with participation in a longitudinal two-stage study conducted in Kyiv following the 1986 Chornobyl nuclear power plant accident.
  
  
  METHODS
  Six hundred child-mother dyads (300 evacuees and 300 classmate controls) were initially assessed in 1997 when the children were 11 years old, and followed up in 2005-6 when they were 19 years old. A population control group (304 mothers and 327 children) was added in 2005-6. Each assessment point involved home interviews with the children and mothers (stage 1), followed by medical examinations of the children at a clinic (stage 2). Background characteristics, health status, and Chornobyl risk perceptions were examined.
  
  
  RESULTS
  The participation rates in the follow-up home interviews were 87.8% for the children (88.6% for evacuees; 87.0% for classmates) and 83.7% for their mothers (86.4% for evacuees and 81.0% for classmates). Children's and mothers' participation was predicted by one another's study participation and attendance at the medical examination at time 1. Mother's participation was also predicted by initial concerns about her child's health, greater psychological distress, and Chornobyl risk perceptions. In 1997, 91.2% of the children had a medical examination (91.7% of evacuees and 90.7% of classmates); in 2005-6, 85.2% were examined (83.0% of evacuees, 87.7% of classmates, 85.0% of population controls). At both times, poor health perceptions were associated with receiving a medical examination. In 2005-6, clinic attendance was also associated with the young adults' risk perceptions, depression or generalized anxiety disorder, lower standard of living, and female gender.
  
  
  CONCLUSIONS
  Despite our low attrition rates, we identified several determinants of selective participation consistent with previous research. Although evacuee status was not associated with participation, Chornobyl risk perceptions were strong predictors of mothers' follow-up participation and attendance at the medical examinations. Understanding selective participation offers valuable insight for future longitudinal disaster studies that integrate psychiatric and medical epidemiologic research.
authors.affiliation: Spanish National Cancer Research Center (CNIO), C/Melchor Fernández Almagro 3, E-28029 Madrid, Spain. ltung@cnio.es
authors.forename: Lin T
authors.initials: LT
authors.lastname: Guey
authors.forename: Evelyn J
authors.initials: EJ
authors.lastname: Bromet
authors.forename: Semyon F
authors.initials: SF
authors.lastname: Gluzman
authors.forename: Victoria
authors.initials: V
authors.lastname: Zakhozha
authors.forename: Vlodomyr
authors.initials: V
authors.lastname: Paniotto
mesh_terms: D000328:Adult; D001294:Attitude to Health; D047852:Chernobyl Nuclear Accident; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D007407:Interviews as Topic; D008137:Longitudinal Studies; D008297:Male; D008603:Mental Health; D009035:Mothers / Q000523:psychology / Q000706:statistics & numerical data; D010358:Patient Participation / Q000523:psychology / Q000706:statistics & numerical data*; D010552:Personality Assessment; D011210:Power Plants; D012306:Risk; D014455:Ukraine