Assessment of Health-Related Quality of Life and Depression Tendency of a Cohort with Prolonged Low-Dose-Rate Radiation Exposure from γ-Radiation Contaminated Buildings in Taiwan

• Main Authors: Pi-Mei Nancy Yen, 顏璧梅
• Other Authors: Chen-Chang Yang
• Format: Others
• Language: en_US
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/33919778089795442264

博士 === 國立陽明大學 === 環境與職業衛生研究所 === 101 === Objectives: We assessed health-related quality of life (HRQoL) and the prevalence of depression tendency of a cohort with prolonged low-dose-rate radiation exposure from γ-radiation contaminated buildings (RCB) in Taiwan. We further investigated the risk factors of various domains of HRQoL and depression tendency, as well as the relation between HRQoL and depression tendency. Findings of the present study could provide important information to improve future healthcare of low-dose-rate radiation exposed subjects. Methods: The study cohort included 7289 subjects and 171,879 person-years of follow-up at the end of 2011. We conducted repeated surveys on HRQoL (2004, 2007 and 2011), and depression tendency (2009 and 2011) by using health-related World Health Organization questionnaire on quality of life- brief version (WHOQOL-BREF) and Beck depression inventory (BDI). Totally, 1166, 1818, 1621 and 1838 subjects completed the survey in 2004, 2007, 2009 and 2011 respectively. We used Chi-square (χ2) test and Student’s t-test or Wilcoxon rank-sum test to compare baseline characteristics between various study groups; and employed simple linear or logistic regression analyses to identify potential predictors of the HRQoL and/or depression tendency. Multiple mixed models and generalized logistic regression model with generalized estimation equations (GEE) method, adjusting for potential confounders and controlling for within-family correlations, were further employed to investigate the differences in study outcomes between different exposure groups. The correlations among outcomes were also examined by using Pearson partial correlation analysis. All statistical analyses were performed by Statistics Analysis System (SAS) statistical package version 9.2 and/or 9.3 (SAS Institute Inc., Cary, NC, USA). A two-tailed P-value of less than 0.05 was considered statistically significant. Results: In the survey conducted in 2004, subjects exposed to low-dose-rate radiation were found to have significantly lower HRQoL scores in physical, psychological and social relationship domains, but not in the environmental domain, as compared to the unexposed population. Meanwhile, those younger than 25 years old had the largest decrease in HRQoL scores, as compared with the older subjects. Furthermore, the difference in HRQoL scores between the exposed and the reference populations for females were larger than those for males in all age groups and in all domains. In 2007, we further found that the HRQoL scores were similar between exposed subjects who had different levels of cumulative exposure. Furthermore, girls aged 12 years or younger at the disclosure of exposure had lower HRQoL scores in physical, psychological, and environmental domains compared to those with later age at disclosure. In addition to the studies on HRQoL, the prevalence of depression tendency (BDI-IA≧12) was high in the exposed population (18.7% in 2009 and 17.8% in 2011 respectively). Gender and age at informed of exposure were shown as important effect modifiers of the associations between exposure and the risk of depression tendency in the 2009 study. When the relation between HRQoL scores and depression tendency were assessed in 2011, strong inverse associations were found between various HRQoL domains and depression scores (correlation coefficient=-0.46, -0.57, -0.39, -0.42, -0.44; p<0.001 for physical, psychological, social relationship, environmental domains and self-scored general HRQoL scores respectively). Among them, psychological domain had the highest inverse correlation with depression scores. Conclusions: We found that HRQoL scores were poor in the low-dose-rate radiation exposed population, and the effect was not directly related to the level of cumulative exposure. Moreover, the prevalence of depression tendency/depression in the exposed cohort seemed to be higher than the general population in Taiwan; and various domains of HRQoL score were inversely correlated with the score of depression tendency. Future studies are warranted to better delineate the complex effects of long-term low-dose-rate radiation exposure on HRQoL and mental health in the exposed cohort. Timely intervention may then be implemented to improve the HRQoL as well as the mental health of the exposed subjects.