Impact of Temperature Variation on Patients with Acute Severe Asthma

Acute severe asthma (ASA) is associated with a heightened risk of death. The influence of ambient temperature on in-hospital mortality and healthcare utilization for patients with ASA is poorly characterized.

Using the National Inpatient Sample, we compared adults hospitalized with ASA in the northeast with southern regions of the United States. We used multivariable regression to determine outcomes (mortality, length of stay, hospital charges, and discharge site after hospitalization). We coupled ambient temperature data for regional comparisons using the National Centers for Environmental Information.

From 2016 to 2019, 5485 patients were admitted with ASA; 2050 (37.4%) were in the Northeast, and 3435 (62.6%) were in the South. Comparison groups had similar mean ages, gender distribution, and comorbidity burden (all P values >0.05). No significant differences with respect to adjusted odds ratio (aOR) of mortality (aOR 0.65, 95% confidence interval [CI] 0.2-2.1, P=0.48) or adjusted mean difference (aMD) in length of stay (aMD 0.82 days, 95% CI -0.0 to 1.6, P=0.05) were observed. Patients in the Northeast had higher hospital charges (aMD $20,986, 95% CI 6743-35,228, P=0.04) and lower odds of being discharged to home (aOR 0.65, 95% CI 0.44-0.97, P=0.03), however. Throughout all months across the 4-year study period, average monthly temperatures were lower in the Northeast compared with the South.

Patients with ASA in the cooler Northeast incurred greater hospital charges and were less likely to be discharged home after hospitalizations than in the South. Future interventions to improve outcome differences may consider ambient temperature factors.