Compared to high income cities, less developed cities in Brazil have a higher hospitalisation rate associated with increased heat exposure, according to a new study published recently in PLOS Medicine by Yuming Guo of the Monash University, Australia, and colleagues.
Heat exposure, which will increase with global warming, is associated with increases in mortality and morbidity but little is known about the socioeconomic disparities in vulnerability to heat. In the new study, researchers collected daily hospitalisation and climate data in the hot season during 2000 through 2015 from 1,814 Brazilian cities covering 78.4% of the Brazilian population. 49 million hospitalisations were studied.
For cities of lower middle income, as classified by the World Bank, every 5°C increase in daily mean temperature during the hot season was associated with 5.1% increase in all-cause hospitalisation; and for cities of middle income, every 5°C temperature increase was associated with a 3.7% increase in hospitalisation. While for cities of high income, the temperature increase was only associated with a 2.6% increase in hospitalisation.
"Increasing heat exposure along with global warming could be a potential driver for exacerbating inter-city health inequalities," the authors say.