Cognitive Decline after a Major Natural Disaster

The Study of the Tsunami Aftermath and Recovery (STAR) is a population-representative
longitudinal survey of households located in districts along the coast of Aceh and North Sumatra, Indonesia at the time of the pre-tsunami baseline, which was conducted 10 months before the tsunami. We have completed 7 post-tsunami follow-ups. Our primary measure of cognitive performance is the Mini Mental State Examination, a screener for Alzheimer’s, assessed 13y post-tsunami on 1,700 adults age >40y. The evolution
of cognitive performance is tracked using an abstract reasoning assessment (Raven’s progressive matrices) as well immediate and delayed 10 word recall conducted 4 times between the tsunami and the 13y assessment. Exposure to the tsunami is measured by location of residence at the time of the tsunami. Because the tsunami was completely unanticipated and whether a community was inundated depended on idiosyncratic features of underwater and shoreline topography, it is a plausibly exogenous source of extreme stress. Controlling age, gender and education, we use multivariable regression to measure the impact of community-level exposure to the tsunami on cognitive performance, taking into account the clustering of the baseline survey. We also examine the impact of individual-specific exposures being swept up in the water, loss of family, loss of livelihoods) and the level of post-traumatic stress reactivity based on symptoms reported by the respondent immediately after the tsunami, one and two years later, to capture the level of stress response experienced by the respondent.