Variables influencing medical usage rates, injury patterns, and levels of care for mass gatherings.

Objectives: Mass gatherings create difficult environments for which to plan emergency medical responses. The purpose of this study was to identify those variables that are associated with increased medical usage rates (MURs) and certain injury patterns that can be used to facilitate the planning process.

Methods: Patient information collected at three types of mass gatherings (professional American football and baseball games and rock concerts) over a three-year period was reviewed retrospectively. Specific variables were abstracted: (1) event type; (2) gender; (3) age; (4) weather; and (5) attendance. All 216 events (total attendance 9,708,567) studied were held in the same metropolitan region. All MURs are reported as patients per 10,000 (PPTT).

Results: The 5,899 patient encounters yielded a MUR of 6.1 PPTT. Patient encounters totaled 3,659 for baseball games (4.85 PPTT), 1,204 for football games (6.75 PPTT), and 1,036 for rock concerts (30 PPTT). The MUR for Location A concerts (no mosh pits) was 7.49 PPTT, whereas the MUR for the one Location B concert (with mosh pits) was 110 PPTT. The MUR for Location A concerts was higher than for baseball, but not football games (p = 0.005). Gender distribution was equal among patrons seeking medical care. The mean values for patient ages were 29 years at baseball games, 33 years at football games, and 20 years at concerts. The MUR at events held when the apparent temperature was 80 degrees F significantly lower statistically than that at events conducted at temperatures <80 degrees F were (18 degrees C) (4.90 vs. 8.10 PPTT (p = 0.005)). The occurrence of precipitation and increased attendance did not predict an increased MUR. Medical care was sought mostly for minor/basic-level care (84%) and less so for advanced-level care (16%). Medical cases occurred more often at sporting events (69%), and were more common than were cases with traumatic injuries (31%). Concerts with precipitation and rock concerts had a positive association with the incidence of trauma and the incidence of injuries; whereas age and gender were not associated with medical or traumatic diagnoses.

Conclusions: Event type and apparent temperature were the variables that best predicted MUR as well as specific injury patterns and levels of care.