Determinants of participation in a longitudinal two-stage study of the health consequences of the Chornobyl nuclear power plant accident

Lin T Guey,Vlodomyr Paniotto,Victoria Zakhozha,Evelyn J Bromet,Semyon F Gluzman

doi:10.1186/1471-2288-8-27

Abstract

BackgroundThe 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.MethodsSix 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.ResultsThe 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.ConclusionDespite 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.

Highlights

The determinants of participation in long-term follow-up studies of disasters have rarely been delineated
▪ Mother's Chornobyl risk perceptions Three risk perceptions were examined: diagnosed with Chornobyl-related illness, perception that child's health was very much affected by the accident, and the Distrust of Authorities scale [44]
▪ Self-reported mental health We considered the occurrence in the previous year of episodes of major depressive disorder (MDD) or generalized anxiety disorder (GAD) as diagnosed by the Composite International Diagnostic Interview (CIDI) version 3.0 [38]

Summary

Introduction

The determinants of participation in long-term follow-up studies of disasters have rarely been delineated. Sudden and violent events, such as explosions and transport disasters, are likely to produce post-traumatic stress responses which may negatively influence an individual's willingness to participate [19] These problems can be minimized by intensive tracking and monitoring of the sample [20], most disaster studies were initially designed as cross-sectional investigations and had no capacity to engage in sample retention activities. In addition to the child's gender and evacuee status, the following background characteristics were obtained from the interview with the mothers: whether the child was in utero at the time of the accident (based on date of birth) and two socio-economic indicators – perceived standard of living (Likert scale developed in Kyiv: 0 = lowest to 10 = highest) and parental education (either parent graduated from university versus less). Statistical analyses Logistic regression analyses, adjusting for group status, were performed to examine associations between key variables and follow-up participation separately for children and mothers. Mother's Chornobyl risk perceptiona Diagnosed with Chornobyl-related illness Child's health perceived as very affected by Chornobyl Distrust of authorities, mean ± SDd

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Discussion

Conclusion