Mass-gathering medicine: a descriptive analysis of a range of mass-gathering event types.

OBJECTIVE: To identify and evaluate the volume, nature, and severity of patient presentations encountered by emergency medical services (EMS) at all mass-gathering events held at or near a southeastern US university. In addition, to compare the existing literature base (single mass-gathering event held in large urban population centers) with a broader variety of events varying in crowd size and locations. METHODS: This was a retrospective review of all EMS records from mass-gathering patient presentations (individual-patient cases) between October 24, 2009, and August 27, 2011. All patrons seen by event-based EMS were included. Events categories included the following: football, concerts, public exhibitions, and nonfootball athletic events. Event volumes were defined as follows: low (<1000 patrons), medium (between 1001 and 15 000 patrons), and large (>15 000 patrons). Case presentation-management categories included the following: trauma, medical, and support (minimal medical intervention required, eg, minor dressing for abrasion, water, etc). Severity categories included the following: mild, moderate, and severe based on the following definitions using both provider assessment and the use of transport to a hospital: minor cases were considered non-life threats and did not result in a transport to a hospital; moderate cases were associated with transports to a hospital; and severe cases were life threats with transport to a hospital. RESULTS: We studied 79 events over the study period. Event volumes were 16.45% high, 79.75% medium, and 3.80% low. A total of 670 cases presented, with a mean of 8.48 cases/event. The football category had the highest mean number of cases with 37.09 cases/event, for a total of 408 cases. The nonfootball, athletic event category had the lowest mean number of cases at 1.83 cases/event. Most (81.82%) of the football events were classified as large volume. Support cases were the most common presentation (43.13%), followed closely by medical complaints (41.94%). Most cases were mild in severity (95.97%). There were 27 cases requiring transport to hospital, with 3 cases being life-threatening. The average patient age was 33 years, with 60.3% female sex. These features are similar to the published information on large event medical attendance. CONCLUSIONS: In this retrospective, descriptive study of a broad range of event type, the most common patient presentations at mass-gathering events were mild in severity, requiring minimal medical intervention. Both transports from the event to a hospital and the occurrence of life threats were uncommon. Our findings are similar to the data found in the existing medical literature.

Mass gathering medicine: event factors predicting patient presentation rates.

This study was conducted to identify the event characteristics of mass gatherings that predict patient presentation rates held in a southeastern US university community. We conducted a retrospective review of all event-based emergency medical services (EMS) records from mass gathering patient presentations over an approximate 23 month period, from October 24, 2009 to August 27, 2011. All patrons seen by EMS were included. Event characteristics included: crowd size, venue percentage filled seating, venue location (inside/outside), venue boundaries (bounded/unbounded), presence of free water (i.e., without cost), presence of alcohol, average heat index, presence of climate control (i.e., air conditioning), and event category (football, concerts, public exhibitions, non-football athletic events). We identified 79 mass gathering events, for a total of 670 patient presentations. The cumulative patron attendance was 917,307 persons. The patient presentation rate (PPR) for each event was calculated as the number of patient presentations per 10,000 patrons in attendance. Overdispersed Poisson regression was used to relate this rate to the event characteristics while controlling for crowd size. In univariate analyses, increased rates of patient presentations were strongly associated with outside venues [rate ratio (RR) = 3.002, p < 0.001], unbounded venues (RR = 2.839, p = 0.001), absence of free water (RR = 1.708, p = 0.036), absence of climate control (RR = 3.028, p < 0.001), and a higher heat index (RR = 1.211 per 10-unit heat index increase, p = 0.003). The presence of alcohol was not significantly associated with the PPR. Football events had the highest PPR, followed sequentially by public exhibitions, concerts, and non-football athletic events. In multivariate models, the strong predictors from the univariate analyses retained their predictive significance for the PPR, together with heat index and percent seating. In the setting of mass event medical care, we note that several factors are strongly associated with an increased patient census, including outside (external) or unbounded venues, the absence of fee water (i.e., without cost), no climate control, percent (occupied) seating, and increasing heat index. Although the presence of alcohol is noted to increase patient needs, it does not do so significantly. Regarding event type, collegiate football games have the highest patient census among the range of other events studied. These findings should be considered during the process of EMS resource planning for mass gatherings.