Risk Factors of Post-Traumatic Stress Disorder (PTSD) after Wenchuan Earthquake: A Case Control Study

Background: Few clues were found in the literature about the independent risk factors for PTSD among earthquake survivors in Sichuan province three years after the 2008 earthquake. Ours was the first case-control study with matching factors of age and distance from the epicenter among survivors age 16 years or older, three years after the catastrophe. Objectives: To identify independent risk factors for PTSD among earthquake survivors. Methods: We performed a population-based matched case-control study. The cases were drawn from earthquake areas three years after the Wenchuan earthquake, including 113 cases who met positive criteria for PTSD symptoms according to the PCL-C (PTSD Checklist-Civilian Version) score and 452 controls who did not meet the criteria. Cases and controls were matched individually by birth year (+ three years) and the town they lived in when the earthquake occurred. Results: Independent risk factors for PTSD symptoms included two-week disease prevalence (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.18-3.13), witnessing someone being killed in the earthquake (OR, 2.04; 95%CI, 1.17-3.58), having no regular income after the earthquake (OR, 0.52; 95%CI, 0.28-0.98), receiving mental health support only one time after the earthquake (OR, 2.43; 95%CI, 1.09-5.42) and lower social support (lower PSSS score) (OR, 0.95; 95%CI, 0.93-0.97). Conclusion: Earthquake experience, suffering from physical illnesses, lack of stable income, and lower social support were associated with PTSD symptoms.