This investigation assessed changes in utilization of inpatient, outpatient, emergency department, and pharmacy services in the aftermath of Hurricane Sandy in 8 counties in New York affected by the storm.

Medicaid data for enrollees residing in 8 counties in New York were used to obtain aggregated daily counts of claims for 4 service types over immediate, 3-month, and 1-year periods following the storm. Negative binomial regression was used to compare service utilization in the storm year with the 2 prior years, within areas differentially affected by the storm.

Changes in service utilization within areas inside or outside the storm zone were most pronounced over the 1-year effect period. Differences in service utilization by year were the same by storm zone designation over the immediate effect period for all services.

Results are consistent with previous investigations demonstrating that some of the greatest effects of a disaster on health services utilization occur well beyond the initial event. One-year effects, combined with some 3-month effects, suggests that storm recovery, with its effect on health care services utilization, may have followed different paths in areas designated as inside or outside the storm zone. (Disaster Med Public Health Preparedness. 2016;10:472–484)