Advancing our Understanding of Heat Wave Criteria and Associated Health Impacts to Improve Heat Wave Alerts in Developing Country Settings

Abstract

Health effects of heat waves with high baseline temperatures in areas such as India remain a critical research gap. In these regions, extreme temperatures may affect the underlying population’s adaptive capacity; heat wave alerts should be optimized to avoid continuous high alert status and enhance constrained resources, especially under a changing climate. Data from registrars and meteorological departments were collected for four communities in Northwestern India. Propensity Score Matching (PSM) was used to obtain the relative risk of mortality and number of attributable deaths (i.e., absolute risk which incorporates the number of heat wave days) under a variety of heat wave definitions (n = 13) incorporating duration and intensity. Heat waves’ timing in season was also assessed for potential effect modification. Relative risk of heat waves (risk of mortality comparing heat wave days to matched non-heat wave days) varied by heat wave definition and ranged from 1.28 [95% Confidence Interval: 1.11–1.46] in Churu (utilizing the 95th percentile of temperature for at least two consecutive days) to 1.03 [95% CI: 0.87–1.23] in Idar and Himmatnagar (utilizing the 95th percentile of temperature for at least four consecutive days). The data trended towards a higher risk for heat waves later in the season. Some heat wave definitions displayed similar attributable mortalities despite differences in the number of identified heat wave days. These findings provide opportunities to assess the “efficiency” (or number of days versus potential attributable health impacts) associated with alternative heat wave definitions. Findings on both effect modification and trade-offs between number of days identified as “heat wave” versus health effects provide tools for policy makers to determine the most important criteria for defining thresholds to trigger heat wave alerts.

WITHDRAWN: Reliability Framework for Characterizing Heat Wave and Cold Spell Events

“…They showed spatial variability 52 of the health risk that is closely tied to the extreme heat and social vulnerability. Nori-Sarma et al (2019) used Propensity Score Matching (PSM) to identify mortality risk of the heat wave 54 in developing countries. They showed that health risk associated with the heat waves varies by 55 different definitions of the heat wave.…”

Does Ethnic Diversity Impact on Risk Perceptions, Preparedness, and Management of Heat Waves?

“…Identifying the perceptions, attitudes and behavior of the varied groups in the population concerning heat waves, should be of high priority for policy-makers and governance systems. Having insights on population behavior and attitudes can tailor risk communication strategies and information directed to the public to the needs and characteristics of the varied population groups ( 12 , 29 ). Campaigns for health protection against heatwaves have to consider psycho-social and cultural characteristics of different ethnicities, as these influence both the perception of the risk and its consequences, as well as the willingness to adopt and implement practical steps in view of the risk ( 28 , 29 ).…”

“…Unless prepared for and mitigated, extreme temperatures can have detrimental health impacts, including excess mortality, even among communities that are accustomed to recurring heat waves ( 7 , 8 ). In the past two decades, heat waves caused excess mortality in many countries, ranging from an increase of 38% ( 7 , 9 , 10 ) to more than 135% ( 11 , 12 ). Sustained heat waves pose a substantial risk for vulnerable populations, including the elderly, young children, individuals that suffer from respiratory or cardiovascular diseases, as well as tourists or migrants that are not accustomed to similar weather conditions or cannot understand heat wave warnings due to language barriers ( 1 , 13 ).…”

“…Introduction of protective means is an important component of heat wave risk management, aimed to mitigate the potential risks to public health ( 19 ). National, regional and local heat wave plans and effective risk communication campaigns are aimed to enhance adaptive behavior of the population and substantially mitigate detrimental health effects ( 12 , 20 ).…”

“…Studies have presented that varied ethnic affiliations may be related to a higher vulnerability to heat waves (resulting from socio-economic and cultural-behavioral differences), such as among African American populations in the US or indigenous Australians, resulting in increased rates of morbidity and mortality ( 21 , 23 ). As ethnicity may impact on both risk perception as well as coping behaviors, there is a need to study the effects of ethnicity on heat wave vulnerability for majority and minority populations ( 12 , 22 ).…”