Are residents of Seattle ready for ‘the Big One? An intervention study to change earthquake preparedness

Background: Community preparedness for natural hazards remains poor across cultures. In addition, evaluated intervention studies in natural hazard preparedness are scarce and contain methodological problems. This study presents results of an intervention study on earthquake preparedness conducted in Seattle, U.S.A. Methodology: This is a quasi-experimental, longitudinal, community intervention with a pretest-posttest design, focused on improving earthquake readiness at the household level. The sample included 157 adult residents of Seattle. Preparedness measures were assessed at baseline, one week after the intervention, and at three and 12 months after the intervention. This involved both of the groups in a survey and an observation of preparedness levels in their homes. The primary outcome measure was an observational tool of five preparedness items, which was implemented alongside a survey that measured psychological, social, demographic and self-reported preparedness variables. In addition, the intervention group completed a six-hour workshop on earthquake preparedness, divided over two days. The control group did not participate in the workshop. Results: The intervention group significantly improved their earthquake preparedness levels compared to baseline and to controls one week after the intervention. Nonetheless, the effect of the intervention faded at the 3-month followup, where no significant differences in earthquake preparedness were observed in the intervention group compared to baseline. In fact, preparedness appeared to increase for controls at three months compared to baseline and to one week after the intervention, and although not reaching statistical significance, it exceeded the intervention group’s preparedness levels. Anxiety and trust predicted earthquake preparedness for the control group at three months. Discussion: Despite levels of earthquake preparedness improving significantly for the intervention group right after the intervention, this effect disappeared at the 3 month follow-up, stressing the need for the field to develop measures to facilitate the maintenance of behaviour change over time. Interestingly, controls continued to improve their levels of preparedness, suggesting that the home assessments themselves might have acted as an intervention that was sufficiently powerful to trigger behaviour change in controls. Contrary to the emphasis on self-efficacy and other cognitive variables in the literature concerning natural hazard preparedness, these results suggest that emotions such as anxiety and trust might play a more important role in preparedness. Future preparedness interventions should put emotive factors centre stage in targeting preparedness. The findings of this study have implications for national and international policies on the design and delivery of community interventions to increase hazard preparedness in lay people