Understanding patterns of use of emergency medical services is important for planning adequate programs, budgets, and schedules. Understanding the factors associated with use of these services can help systems target high-risk populations or behaviors and allocate budgetary resources appropriately. Previous data have shown an association between the use of emergency health care use and distribution of welfare check distribution in both the United States and Canada. These data have limitations. In these studies, no attempt was made to investigate whether this increase in use was for particular types of complaints (medical or traumatic) or true outside of an urban community. The purpose of this study was to investigate whether there were similar monthly associations in patterns of use of a regional transport service for either medical or traumatic complaints.

Med Flight is a regional aeromedical service operated by the University of Wisconsin. The service provides transport services to all hospitals and emergency medical services for critically ill or injured patients inside a radius of approximately 75 miles. The program transports approximately 1200 patients per year. Data for all transports for the years 1998-2004 were obtained. Daily numbers of transports were then compared for all patients and subsets of those with specifically traumatic or cardiac-related complaints.

There were 7756 transports during the study period: 34% of the transports were trauma related; 30% were cardiac related.

There was a significant association between trauma-related flights and both month of the year (P < .0001) and day of the week (P < .001), but not for total or cardiac-related flights. There was no association between day or week of the month and transports.

In contrast to previous studies, these findings show no association between use of a regional transport service and time of the month. Determinants of use of emergency services may differ between urban and nonurban areas.