The effect of energy poverty on mental health, cardiovascular disease and respiratory health: a longitudinal analysis.

Background: Houses in mild-climate countries, such as Australia, are often ill-equipped to provide occupants protection during cold weather due to their design. As a result, we rely on energy to warm homes, however, energy is becoming increasingly expensive, and evidence is emerging of a sizable burden to population health of being unable to afford to warm homes causing exposure to cold indoor temperatures. Methods: We use a large longitudinal sample of adult Australians (N = 32,729, Obs = 288,073) collected annually between 2000 and 2019 to estimate the relationship between exposure to energy poverty and mental health (SF-36 mental health score), and a smaller sample from waves collected in 2008-9, 2012-13, and 2016-17 (N = 22,378, Obs = 48,371) to estimate the relationship between energy poverty and onset of asthma, chronic bronchitis or emphysema, hypertension, coronary heart disease, and depression/anxiety. Fixed effects and correlated random-effects regression was used in models. As exposure and outcomes were self-reported, we tested alternative specifications of each to examine bias from measurement error. Findings: When people can no longer afford to warm their homes, their mental health declines significantly (by 4.6-points on the SF-36 mental health scale, 95% CI -4.93 to -4.24), their odds of reporting depression/anxiety or hypertension increases by 49% (OR 1.49, 95% CI 1.09 to 2.02) and 71% (OR 1.71, 95% CI 1.13 to 2.58) respectively. The findings for the decline in mental health were supported in additional analyses that tested alternative specifications of the exposure measure, including co-resident verification of respondent reporting of being able to afford to warm the home. Support for an effect of energy poverty on hypertension was less clearly supported in these same sensitivity models. There was little evidence of an effect of energy poverty on asthma or chronic bronchitis onset in this adult population noting, however, that we could not examine exacerbation of symptoms. Interpretation: Reducing exposure to energy poverty should be considered as an intervention with clear benefits for mental health and potential benefits for cardiovascular health. Funding: National Health and Medical Research Council, Australia.