What Is the Prevalence of Post-Traumatic Stress Reaction After an Earthquake Disaster? Evidence From a Meta-Analysis of Worldwide Reports

Introduction: Although there have been many case reports of earthquake disasters describing each prevalence rate (PR) of Post-Traumatic Stress Reaction (PTSR) in the disaster-stricken area, few meta-analytic studies have tried to integrate them for preparing for the next tragic disaster. As part of a study titled “Research on Strengthening DPAT Functions and Preparing for the Nankai Trough Earthquake,” we reviewed and analyzed literature on PTSR following earthquake disasters worldwide. The study aims to evaluate the impacts of general earthquake disasters on the occurrence of PTSR and to estimate spatiotemporal PRs of PTSR in the affected area. Methods: A systematic review is conducted by using four search engines, including Ichushi Web, PubMed, CiNii, and CINAHLin by the PRISMA guideline. We searched papers from 1970 to the present with the keywords “earthquake” OR “tsunami” AND “mental health” OR “psychiatry” OR “post-traumatic stress disorder” OR “depression” OR “psychological” OR “stress.” This yielded a total of 2,930 articles. Including criteria is a research study written in English or Japanese reporting PR of PTSD or PTSR in the disaster-affected area. Results: After excluding duplicates and studies that did not meet our criteria, we focused on 265 articles. Our review covers studies from various regions, with 109 from China, 50 from Japan, 18 from Italy, 16 from Indonesia, 15 from Turkey, and so on. Weighted averages of PRs integrated by periods after earthquakes were 29.0% in 3 months, 19.2% in one year, 18.8% in 3 years, and 20.2% in 10 years. The highest PR integrated by country or affected population was 60.9% in Turkey, and was 80% in the bereaved family for each. However, there were also significant research biases in some of these studies. Conclusion: This study highlights the substantial psychological impact of earthquake disasters and supports the need for enhanced mental health response strategies.