Impacts between Temperature and Precipitation Changes on Visits to Mental Health Emergency Departments the Midwest

Global climate change is widely viewed as one of the most significant challenges facing population public health. A continued lack of progress in reducing global emissions means continued and growing threats to human lives and healthcare systems. There is also increasing recognition of climate change’s impact on mental health and that these impacts will be felt disproportionately in marginalized populations and vulnerable groups. Despite this recognition, the field of climate change and mental health research is often described as “under-studied”. This is especially true in the US Midwest region, despite demonstrated increases in daily average temperature, changes in precipitation, and more frequent flooding events linked to climate change. The frequency and severity of these adverse weather events are projected to continue to rise due to continued changes in climate. It is therefore imperative to understand the nature of how climate change will impact mental health and the mental health service system within the Midwest. The emergency department is increasingly recognized as an important mental health service point. However, relatively few studies have examined linkages between demonstrated climate change-related weather impacts and emergency department utilization for mental health reasons. To address these gaps, this study examined whether the number of adult emergency department visits for mental health and psychosocial problems varies with changes in temperature or precipitation. Monthly data from the Nationwide Emergency Department Sample was used combined with the Midwestern Regional Climate Center examining 12 regions in Iowa and Missouri. Incidence rate ratios for mean temperature and total precipitation were estimated by using Poisson regression and generalized additive models. Sub-group analysis was conducted by age (under/over age 65), race (white vs. non-white), and region (urban vs. rural). Results suggest overall increased use of emergency departments for mental health problems with higher mean temperatures, particularly for racial minorities. Visits were also significantly increased with increases in precipitation in rural populations. Climate change may continue to make findings from this study increasingly important and relevant, as overcrowding and boarding related to the continued rise of ED visits for mental health reasons has already been identified as a national health crisis by the American Academy of Emergency Medicine and the National Academy of Medicine. Hospitals and the mental health service system would benefit from preparing and adjusting for this ever-present new reality. Future studies would also benefit from understanding the specific mechanisms connecting climate change and emergency department mental health service use to inform interventions to mitigate the use of acute mental healthcare services.