Critical determinants of morbidity and adverse outcomes during the Hajj using the Haddon matrix and the combined model

Hajj, the annual pilgrimage to Makkah, Saudi Arabia, attracts around two million Muslims from across the globe, making it one of the world's largest mass gatherings. This event is associated with different public health challenges due to the scale of participation, the diversity of attendees, the complexity of the rituals, and the extreme physical and environmental conditions individuals encounter on their pilgrimage. This study employed the Haddon Matrix and Combined Model frameworks to categorize risk factors into pre-event, during-event, and post-event phases. A comprehensive literature review was conducted, and data were extracted from peer-reviewed articles on health outcomes associated with Hajj. Factors across human, environmental, and agent domains were analyzed, and the effectiveness of various public health strategies to reduce adverse outcomes during Hajj was assessed. This study comprehensively examined the factors contributing to morbidity and adverse outcomes during Hajj. Cardiovascular diseases, respiratory infections, and heat-related illnesses were identified as the primary causes of morbidity, and older adults and individuals with pre-existing conditions were more affected.