Psychological Distress in Responders and Nonresponders in a 5-year Follow-up Health Survey: The RIAS Study

BACKGROUND: People with poor health or mental conditions are generally unwilling to participate in the health examinations, and no studies have directly examined the relationship of psychological distress among disaster survivors with participation status to date. The present study thus examined psychosocial differences according to the respondent status in a 5-year follow-up survey among participants in the prospective health surveys on survivors of the Great East Japan Earthquake and Tsunami Disaster study in Iwate Prefecture, Japan. METHODS: We analyzed data from 10,203 Japanese survivors aged ≥18 years (mean age, 65.6 years; 38.0% men) and who underwent health examinations at baseline in 2011. Participants were classified into responders and nonresponders according to their 2015 health examination participation status. Psychological distress was evaluated using the Kessler 6 scale and categorized as none, mild, and severe. Multinominal logistic regression was used to examine the risk of psychological distress in relation to participation status. RESULTS: In the 2015 survey, 6,334 of 6,492 responders and 1,686 of 3,356 nonresponders were analyzed. The most common reasons for nonparticipation in the survey were participated in other health examinations, examined at a hospital, and did not have time to participate. Nonresponse in males was associated only with mild psychological stress, whereas nonresponse in females was associated with mild and severe psychological distress. CONCLUSION: Nonresponders in the follow-up survey had a higher risk of psychological distress than responders. Continuous monitoring of the health of nonresponders and responders may help to prevent future health deterioration.