Effect of tsunami drill experience on evacuation behavior after the onset of the Great East Japan Earthquake

The effectiveness of tsunami drills in guiding evacuation behavior remains uninvestigated. Accumulation of evidence regarding the effectiveness of tsunami drills would be beneficial for improving survival and health of communities to be inundated by a tsunami. A questionnaire to inquire participants' location at the onset of the Great East Japan Earthquake and experience of the tsunami was issued as part of a survey of total adult residents of Shichigahama town whose houses were significantly damaged by the disaster. Along with the location information, self-reported information on participation in tsunami disaster drills and attendance of a lecture about tsunamis before the disaster and whether the participants evacuated after the earthquake was subjected to multiple logistic regression analyses adjusted for potential confounding factors. Amongst the 2314 participants who were present in the town at the onset of the disaster and completed the questionnaires, 1560 (67%) evacuated after the earthquake. The rate of evacuation was significantly higher amongst the population who participated in tsunami disaster drills before the event than amongst those who did not participate (multivariate-adjusted odds ratio [MOR] = 1.99, 95% confidence interval [CI] = 1.53-2.61, p < 0.01). However, other experience of earthquake and tsunami disaster prevention before the event did not affect evacuation behavior (MOR = 0.86-1.16). A survey of the population who survived the catastrophe provides initial evidence to advocate the administration of tsunami drills in seaside communities to enhance the evacuation behavior immediately after the disaster onset.