Geographic Distribution of Disaster-Specific Emergency Department Use After Hurricane Sandy in New York City

Abstract

Objective: We aimed to characterize the geographic distribution of post-Hurricane Sandy emergency department use in administrative flood evacuation zones of New York City.

Methods: Using emergency claims data, we identified significant deviations in emergency department use after Hurricane Sandy. Using time-series analysis, we analyzed the frequency of visits for specific conditions and comorbidities to identify medically vulnerable populations who developed acute postdisaster medical needs.

Results: We found statistically significant decreases in overall post-Sandy emergency department use in New York City but increased utilization in the most vulnerable evacuation zone. In addition to dialysis- and ventilator-dependent patients, we identified that patients who were elderly or homeless or who had diabetes, dementia, cardiac conditions, limitations in mobility, or drug dependence were more likely to visit emergency departments after Hurricane Sandy. Furthermore, patients were more likely to develop drug-resistant infections, require isolation, and present for hypothermia, environmental exposures, or administrative reasons.

Conclusions: Our study identified high-risk populations who developed acute medical and social needs in specific geographic areas after Hurricane Sandy. Our findings can inform coherent and targeted responses to disasters. Early identification of medically vulnerable populations can help to map "hot spots" requiring additional medical and social attention and prioritize resources for areas most impacted by disasters. (Disaster Med Public Health Preparedness. 2016;10:351-361).

Keywords: disaster medicine; emergency department utilization; geographic information systems; vulnerable populations.

Figure 1

New York City Flood Evacuation Zones. Revised administrative New York City flood evacuation zones established by the New York City Office of Emergency Management.

Figure 2

Deviations in Daily ED Utilization in 2012 Stratified by Evacuation Zones.

Figure 3

Primary ICD-9 Diagnosis Code Categories With Increased Frequency Among ED Patients as Stratified by Evacuation Zone. Abbreviations: ED, emergency department; ICD-9, International Classification of Diseases, 9th Revision.

Figure 4

Secondary ICD-9 Diagnosis Code Categories With Increased Frequency Among ED Patients as Stratified by Evacuation Zone. Abbreviations: ED, emergency department; ICD-9, International Classification of Diseases, 9th Revision.