Validation of a Belgian Prediction Model for Patient Encounters at Belgium's Largest Public Cultural Mass Gathering

OBJECTIVE: To compare actual patient presentation rates from Belgium's largest public open-air cultural festival with predictions provided by existing models and the Belgian Plan Risk Manifestations model.

METHODS: Retrospectively, actual patient presentation rates gathered from the Ghent Festivities (Belgium) during 2013-2019 were compared to predicted patient presentation rates by the Arbon, Hartman, and PRIMA models.

RESULTS: During 7 editions, 8673000 people visited the Ghent Festivities; 9146 sought medical assistance resulting in a mean patient presentation rate (PPR) of 1.05. The PRIMA model overestimated the number of patient encounters for each occasion. The other models had a high rate of underprediction. When comparing deviations in predictions between the PRIMA model to the other models, there is a significant difference in the mean deviation (Arbon: T = 0.000, P < 0.0001, r = -0.8701; Hartman: T = 0.000, P < 0.0001, r = -0.869).

CONCLUSION: Despite the differences between the predictions of all 3 models, our results suggest that the PRIMA model is a valid tool to predict patient presentations to IEHS during public cultural MG. However, to substantiate the PRIMA model even further, more research is needed to further validate the model for a broad range of MG.