Air pollution and comorbidity burden influencing acute hospital mortality outcomes in a large academic teaching hospital in Dublin, Ireland: a semi-ecologic analysis

• Published in: Public health (London) 2020-09, Vol.186, p.164-169
• Main Authors: White, P.F., Conway, R.P., Byrne, D.G., O'Riordan, D.M.R., Silke, B.M.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Air; Air pollution; Air Pollution - adverse effects; Air Pollution - analysis; Air pollution measurements; Comorbidity; Confidence intervals; Diameters; Emergency medical services; Female; Hospital Mortality - trends; Hospital outcomes; Hospitalization; Hospitals, Teaching; Humans; Interactions; Ireland - epidemiology; Male; Middle Aged; Mortality; Mortality rates; Particulate emissions; Particulate matter; Particulate Matter - adverse effects; Particulate Matter - analysis; Patient Admission; PM10; Pollutants; Pollution levels; Regression analysis; Regression models; SO2; Statistical analysis; Sulfur; Sulfur dioxide; Sulfur Dioxide - adverse effects; Sulfur Dioxide - analysis; Teaching; Teaching hospitals
• ISSN: 0033-3506; 1476-5616
• DOI: 10.1016/j.puhe.2020.07.023

To investigate the extent to which air pollution interacts with comorbidity in determining mortality outcomes of emergency medical admissions. Routinely collected data were used to study all emergency medical admissions to an academic teaching hospital in Dublin, Ireland, from 2002 to 2018. Air pollution was measured by particulate matter with aerodynamic diameter ≤10 μm (PM10) and sulphur dioxide (SO2) levels on the day of admission. Comorbidity Score was measured using a previously derived score. A multivariable logistic regression model was used to relate air pollutant levels, Comorbidity Scores, and their interaction to 30-day in-hospital mortality. There were 102,483 admissions in 58,127 patients over 17 years. Both air pollutant levels and Comorbidity Score were associated with 30-day in-hospital mortality. On admission days with PM10 levels above the median, mortality was higher (Odds ratio [OR] 1.09; 95% confidence interval [CI] 1.06, 1.18) at 11.2% (95% CI 10.5, 12) compared with 10.4% (95% CI 10, 10.7) on days when PM10 levels were below the median. On admission days with SO2 levels above the median, mortality was higher (OR 1.13; 95% CI 1.10, 1.16) at 12.2% (95% CI 11.4, 13) compared with 10.7% (95% CI 10.3, 11.1) on days when SO2 levels were below the median. Comorbidity Score was strongly associated with mortality (mortality rate of 8.9% for those with a 6-point score vs mortality rate of 30.3% for those with a 16-point score). There was limited interaction between air pollutant levels and Comorbidity Score. Both air pollution levels on the day of admission and Comorbidity Score were associated with 30-day in-hospital mortality. However, there was limited interaction between these two factors. •Air pollution and comorbidity burden are both associated with 30-day in-hospital mortality in acute medical admissions.•The underlying comorbidity burden does not appear to significantly modify air pollution–associated mortality.•The impact of air pollution on in-hospital mortality appears to be significant even at low levels.