Healthy Aging Research
Open Access

Abstract

Who should heat prevention plans target? A heat susceptibility indicator in the elderly developed based on administrative data from a cohort study

Patrizia Schifano, Giovanna Cappai, Manuela De Sario, Anna Maria Bargagli, Paola Michelozzi

Background: A heat susceptibility indicator based on current information systems was developed in order to identify elderly subjects at increased risk of dying during heat-wave days compared to non-heat-wave days.

Methods: Susceptibility was measured as the relative difference between the predicted probabilities of dying during heat-wave days and non-heat-wave days, estimated through a Poisson generalized linear model. The study analyzed a cohort of residents in Rome aged 65+ between 2005 and 2007 and examined the following factors: age, gender, marital status, socioeconomic position, and clinical conditions.

Results: A total of 624,561 subjects were analyzed. The indicator performed well for the 65–74 age group, but not for the 75+ age group, for whom we computed an alternative index based on the absolute difference rather than the relative difference between the predicted probabilities. Moreover, the indicator revealed that 65–74 year-old subjects displaying the highest susceptibility (top 5%) to death during heat waves had at least one of the selected chronic pathologies, and 90% of them had chronic obstructive pulmonary disease. Additionally, 60% of those with the highest susceptibility among 75+ year olds had at least three chronic diseases, 80% were women, and 90% were not married.

Conclusions: The susceptibility indicator currently used in Rome is a valid and significant tool for selecting atrisk elderly subjects who can benefit from heat prevention programs. Also, this heat susceptibility indicator, which is based on administrative data only, does not require additional cost for implementation and could be easily adapted to other populations.