A Meta Analysis of Indoor Temperature Impacts on Sleep Duration, Mortality Risk, and Economic Costs in Older Adults

TL;DR

This study examines how indoor temperature affects sleep, health, and costs in older adults, suggesting that improving home environments could reduce health risks and expenses.

Contribution

The novel contribution is quantifying the economic costs of sleep loss due to uncomfortable indoor temperatures in older adults.

Findings

Uncomfortably warm indoor temperatures are linked to reduced sleep duration in older adults.

Short sleep duration is associated with increased all-cause mortality in older adults (pooled RR: 1.08).

Estimated health costs from sleep loss in hot homes are $96,590 (90% CI: $10,240, $362,000).

Abstract

Of U.S. householders aged 60+, 19% reported difficulty paying energy bills and 11% kept their homes at unhealthy indoor temperatures (IT). Extreme IT may impact sleep health. Healthy sleep is essential for daily functioning and long-term health, yet 33% of adults report short sleep duration (SSD, < 7 hours). Quantifying IT-sleep associations can inform residential weatherization and energy-efficiency programs, including insulation and high-efficiency heating/cooling system installation. We characterized the relationship between IT and SSD and the resulting health costs of temperature-associated sleep loss. We conducted a review and meta-analyses of associations between IT and SSD and also SSD and all-cause mortality. We estimated costs of increased all-cause mortality attributable to SSD in uncomfortably warm homes as the product of 4 terms: prevalence (20%, representing probability) of 6-hour (1 hour less than SSD threshold) sleep duration in older adults, the IT-SSD association, the SSD-mortality association, and a value-of-statistical-life metric, with bootstrapped 90% confidence intervals. Based on results from the literature, we assumed that increases in bedroom IT from comfortable (22 °C) to uncomfortable (30 °C) temperatures were linked to reduced sleep duration by 1 hour in older adults. Additionally, our meta-analysis of 18 studies found SSD is associated with increased all-cause mortality in older adults (pooled RR: 1.08, 95% CI: 1.01, 1.14). Sleep-attributable health costs in uncomfortably hot households were $96,590 (90% CI: $10,240, $362,000). Indoor-environment improvements, including weatherization and energy efficiency upgrades, may offset substantial sleep-related health costs, potentially informing funding mechanisms for these programs.