Mass gathering events: a retrospective analysis of the triage categories, type of injury or medical complaint and medical usage rates

BackgroundAdequate on-site first aid delivery at mass gatherings (MGs) is one of the cornerstones to ensure safe and healthy MGs. We investigated medical usage rates, frequency of triage categories and type of injury or medical complaint, among attendees at MGs in Belgium.MethodsWe analysed the Medical Triage and Registration Informatics System database, which includes prospectively collected person-level data regarding individuals visiting on-site posts at MGs in Belgium. MGs attended by >10 000 people and organised ≥5 times between 2009 and 2018 were included. We determined the proportion of patients in each triage category (‘first aid’ vs ‘medical condition’ vs ‘medical emergency’ vs ‘no treatment’) and each type of injury or medical complaint, and we calculated patient presentation rate (PPR) and transfer to hospital rate (TTHR).ResultsTwenty-eight MGs, totalling 194 events, were included involving 148 265 patient visits. ‘First aid’ was the most common triage category (80%, n=118 514). The need for a nurse/physician (‘medical condition’), and for the treatment of life-threatening conditions (‘medical emergency’) was rare (8.9%, n=13 052, and 0.6%, n=860, of all patient presentations, respectively), but remarkably higher during indoor electronic dance music (EDM) events (17.8% (n=26 391) and 4.0% (n=5930), of all patient presentations, respectively). ‘Skin wounds’ were the most common injury category (42.4%, n=62 275). ‘Respiratory problems’, ‘neurological problems’, ‘intoxication’, ‘heart complaints’ and ‘gastrointestinal complaints’ were more frequent during indoor (electronic) dance, whereas ‘burns’, ‘fracture/contusion’ and ‘skin wounds’ were higher during outdoor music, sports events and city festivals, respectively. PPR (per 10 000 attendees) was highest for outdoor EDM and outdoor music (median 130 (IQR 79) and 129 (IQR 104), respectively). TTHR (per 10 000 attendees) was highest for indoor EDM (median 4.4 (IQR 8.5)).ConclusionMedical usage rates, proportion of patients in triage and injury or medical complaint categories varied across different MG categories, suggesting opportunities for planning medical coverage at these events.