Post Traumatic Stress Disorder and Social Context

Post traumatic stress (PTS) sympthoms may arise when a person is subject to trauma. One of the multiple sources of trauma is the experience of a major natural disaster. We study the development of PTS sympthomathology after the earthquake and tsunami that struck Chile in 2010. Our goal is to understand how pre-disaster social context variables are associated to symptom prevalence after the disaster has striken, when disaster intensity and the extent of destruction have been taken into account. We also study how the different response and coping mechanisms (individualistic versus communitary) are associated to PTS sympthomatology.

For this purpose, we use several data sources. The Post-Terremoto survey was gathered as a followup of the nationally representative household survey that was collected a few months before the 2010 Chilean earthquake and tsunami streaked. Therefore, we have several pre-disaster contextual information such as poverty, income, ocupational status, health, family size and organization, among others. In the follow up persons were requested to respond the Davidson’s trauma battery to evaluate PTS symptoms, leading to 25600 valid PTS scores. Information about degree of household and other community goods destruction was also gathered, together with information about coping strategies (whether the affected individuals relied on recently organized neighborhood networks or acted individually/relying on close family networks). We complemented this data with information from other sources, such as the strength of the earthquake and the tsunami, the history of replicas, and the death rate (at the municipal level). We also added other social context variables such as local criminality and domestic violence.

Several models were estimated with PTS sympthomatology as the dependent variable. Individual level and hierarchical regression models were complemented with further studies of the mean and centile distribution symptoms at the municipal level, through linear and quantile regression methods.