Overlooked heat-related morbidity indicator

Abstract

TPS 661: Climate change: temperature effects 1, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Background: Heat exposure is known to have a complex set of physiological effects and pose threat to the whole population. However, current investigations of heat effects were mostly based on several prespecified health outcomes, and less is known about heat impacts of population morbidity. As the front line of medical services, ambulance dispatches may provide a further understanding of health impacts of heat in the population scale. Methods: Daily ambulance dispatches and temperature between 2015 and 2016 in Shenzhen were analyzed. Records of dispatch include individual characteristics and preliminary diagnoses. We first explored the relationship between temperature and ambulance dispatches and set the optimum temperature using distributed lag nonlinear model. Then, stratified analyses by gender, age and wide range of diagnoses were performed to identify vulnerable subpopulations. We estimated the temperature effect on dispatch by comparing the 95th percentile versus optimum temperature, as determined from the annual time series. Results: A total of 334,495 ambulance dispatches were reported, with average daily demand of 458. Significantly rising risk of ambulance dispatches was found during heat events (RR= 1.19, 95%CI: 1.11-1.27). The risks generally occurred immediately and lasted for less than 1 day. Both male and female, along with people aged 18–44, and ≥60 years old were susceptible to heat. Highest risk was found for urinary disease (RR=1.75, 95% CI: 1.39-2.20), following 1.41 (95% CI: 1.19-1.67) for alcohol intoxication, 1.24 (95% CI: 1.03-1.50) for obstetric and gynecological disease,1.23 (95% CI: 1.08-1.41) for dizziness, 1.22 (95% CI: 1.01-1.48) for respiratory disease, 1.19 (95% CI: 1.08-1.31) for traumatic disease,1.18 (95% CI: 1.01-1.38) for gastrointestinal disease. Conclusion: Heat poses a wide range of impacts on human health, especially among the middle-aged people and the elderly. Better understanding of these impacts and population vulnerabilities through heat-ambulance dispatches, local communities can improve early preparedness and interventions.