Mortality in US Hemodialysis Patients Following Exposure to Wildfire Smoke

Abstract

BackgroundWildfires are increasingly a significant source of fine particulate matter (PM2.5), which has been linked to adverse health effects and increased mortality. ESKD patients are potentially susceptible to this environmental stressor.MethodsWe conducted a retrospective time-series analysis of the association between daily exposure to wildfire PM2.5 and mortality in 253 counties near a major wildfire between 2008 and 2012. Using quasi-Poisson regression models, we estimated rate ratios (RRs) for all-cause mortality on the day of exposure and up to 30 days following exposure, adjusted for background PM2.5, day of week, seasonality, and heat. We stratified the analysis by causes of death (cardiac, vascular, infectious, or other) and place of death (clinical or nonclinical setting) for differential PM2.5 exposure and outcome classification.ResultsWe found 48,454 deaths matched to the 253 counties. A 10-μg/m3 increase in wildfire PM2.5 associated with a 4% increase in all-cause mortality on the same day (RR, 1.04; 95% confidence interval [95% CI], 1.01 to 1.07) and 7% increase cumulatively over 30 days following exposure (RR, 1.07; 95% CI, 1.01 to 1.12). Risk was elevated following exposure for deaths occurring in nonclinical settings (RR, 1.07; 95% CI, 1.02 to 1.12), suggesting modification of exposure by place of death. “Other” deaths (those not attributed to cardiac, vascular, or infectious causes) accounted for the largest portion of deaths and had a strong same-day effect (RR, 1.08; 95% CI, 1.03 to 1.12) and cumulative effect over the 30-day period. On days with a wildfire PM2.5 contribution >10 μg/m3, exposure accounted for 8.4% of mortality.ConclusionsWildfire smoke exposure was positively associated with all-cause mortality among patients receiving in-center hemodialysis.

Association of short-term exposure to ambient PM2.5with hospital admissions and 30-day readmissions in end-stage renal disease patients: population-based retrospective cohort study

“…Additionally, PM 2.5 exposure during wildfire periods has been shown to increase the risk of mortality among patients managing their end-stage renal disease (ESRD) with haemodialysis. 12 However, the role of short-term PM 2.5 exposure at ambient levels on progression of disease and cause-specific morbidities has not been characterised. CKD is a progressive condition that affects 8%-16% of the population worldwide, [13][14][15] and in the final stage, ESRD, many patients are transitioned to haemodialysis to prolong life.…”

“… 3 8–11 Additionally, PM 2.5 exposure during wildfire periods has been shown to increase the risk of mortality among patients managing their end-stage renal disease (ESRD) with haemodialysis. 12 However, the role of short-term PM 2.5 exposure at ambient levels on progression of disease and cause-specific morbidities has not been characterised.…”

Ambient Air Pollution and Mortality among Older Patients Initiating Maintenance Dialysis

“…Furthermore, patients with kidney failure in Hong Kong were quite different from those in the USA in terms of primary renal diagnosis [32]. Another recent study investigating the short-term effect of wildfire smoke conducted among hemodialysis patients in the USA found that a 10 μg/m 3 increase in wildfire PM 2.5 was associated with a 1.04-fold (95% CI: 1.01-1.17) increase in the same-day mortality [33]. All these findings support that air pollution is a potential threat to the health of patients with kidney failure.…”

Respiratory Impacts of Wildland Fire Smoke: Future Challenges and Policy Opportunities. An Official American Thoracic Society Workshop Report

“…There is also growing evidence of acute cardiovascular health effects of wildland fires (16,(20)(21)(22)(23), although cardiovascular studies to date have been less consistent than respiratory studies (11,12,19,24,25). In addition, there is emerging evidence that wildland fire smoke affects outcomes among those with diabetes and end-stage renal disease (16,(26)(27)(28).…”