# The Effectiveness of Two Interventions for Improving Knowledge of Emergency Preparedness Amongst Enrollees of the World Trade Center Health Registry: A Randomized Controlled Trial

## TL;DR

This study compared two methods—mailing a brochure or making a phone call—to improve emergency preparedness knowledge among a disaster-exposed population, finding both equally effective.

## Contribution

Demonstrates that both mailed brochures and structured phone calls are equally effective for improving emergency preparedness knowledge in a disaster-exposed population.

## Key findings

- Both interventions increased emergency preparedness knowledge from baseline to post-intervention.
- The effectiveness of the brochure and phone call interventions was statistically similar.
- 702 enrollees were analyzed, with no significant difference in outcomes between the two groups.

## Abstract

Natural and man-made disasters are occurring more frequently, making household emergency preparedness essential for an effective response. Enrollees of the World Trade Center Health Registry have been found to be less prepared than the US national average despite their prior disaster exposure. The purpose of this study was to evaluate and compare the effectiveness of two interventions—a mailed brochure and a structured phone call—for increasing emergency preparedness knowledge among this population. We conducted a two-arm parallel group trial between February 2019 and August 2020. Participants were Registry enrollees who completed the Wave 4 Registry (2015–2016) survey, whose primary language was English or Spanish, who lived in New York City, and who did not report being a rescue and recovery worker affiliated with FDNY or NYPD. Enrollees were randomized to receive either a brochure by mail summarizing the components of emergency preparedness or a 15 min phone call describing the same. The primary outcome measure was the number of “yes” responses to the ten-item CDC CASPER emergency preparedness questionnaire, measured at baseline and post-intervention. Enrollees were sequentially alternatively assigned to either the brochure or phone call groups. In total, 705 enrollees were assigned to the brochure (n = 353) or phone call (n = 352) groups, and a total of 702 enrollees were analyzed. The Incident Rate Ratio (IRR) for the effect of time was 1.17 (95% CI = (1.14, 1.20)) and for intervention was 1.00 (95% CI = (0.95, 1.05)) Both the brochure and phone call interventions improved knowledge of emergency preparedness from baseline to post-intervention assessment, and to the same extent.