RT Journal Article SR Electronic T1 The 2022 Summer record-breaking heatwave and health information-seeking behaviours: an infodemiology study in Mainland China JF BMJ Global Health JO BMJ Global Health FD BMJ Publishing Group Ltd SP e013231 DO 10.1136/bmjgh-2023-013231 VO 8 IS 9 A1 Li, Zhiwei A1 Fan, Yinguang A1 Su, Hong A1 Xu, Zhiwei A1 Ho, Hung Chak A1 Zheng, Hao A1 Tao, Junwen A1 Zhang, Yunquan A1 Hu, Kejia A1 Hossain, Mohammad Zahid A1 Zhao, Qi A1 Huang, Cunrui A1 Cheng, Jian YR 2023 UL http://gh.bmj.com/content/8/9/e013231.abstract AB Introduction Heatwave is a major global health concern. Many countries including China suffered a record-breaking heatwave during the summer of 2022, which may have a significant effect on population health or health information-seeking behaviours but is yet to be examined.Methods We derived health information-seeking data from the Baidu search engine (similar to Google search engine). The data included city-specific daily search queries (also referred to Baidu Search Index) for heat-sensitive diseases from 2021 to 2022, including heatstroke, hospital visits, cardiovascular diseases and diabetes, respiratory diseases, mental health and urological diseases. For each city, the record-breaking heatwave days in 2022 were matched to days in the same calendar month in 2021.Results The 2022 record-breaking heatwave hit most cities (83.64%) in Mainland China. The average heatwave duration was 13 days and the maximum temperature was 3.60°C higher than that in 2021 (p<0.05). We observed increased population behaviours of seeking information on respiratory diseases (RR=1.014, 95% CI: 1.008 to 1.020), urological diseases (RR=1.011, 95% CI: 1.006 to 1.016) and heatstroke (RR=1.026, 95% CI: 1.016 to 1.036) associated with the heatwave intensity in 2022 (per 1°C increase). The heatwave duration in 2022 (per 1 day increase) was also associated with an increase in seeking information on cardiovascular diseases and diabetes (RR=1.003, 95% CI: 1.002 to 1.004), urological diseases (RR=1.005, 95% CI: 1.002 to 1.008), mental health (RR=1.009, 95% CI: 1.006 to 1.012) and heatstroke (RR=1.038, 95% CI: 1.032 to 1.043). However, there were substantial geographical variations in the effect of the 2022 heatwave intensity and duration on health information-seeking behaviours.Conclusion This infodemiology study suggests that the 2022 summer unprecedented heatwave in Mainland China has significantly increased population demand for health-related information, especially for heatstroke, urological diseases and mental health. Population-based research of real-time disease data is urgently needed to estimate the negative health impact of the exceptional heatwave in Mainland China and elsewhere.Data are available in a public, open access repository. Baidu Search Index records can be obtained from the official Baidu index website (https://index.baidu.com/). Daily ambient temperature and dew temperature data covering the same study period can be obtained from the ERA5-Land dataset (https://cds.climate.copernicus.eu/). Population data can be obtained from the WorldPop dataset (https://hub.worldpop.org/). The daily ambient mean concentration of PM2.5 and O3 can be obtained from the Tracking Air Pollution in China (TAP, http://tapdata.org.cn).