OBJECTIVES: Pneumonia is associated with increased mortality and morbidity, particularly among elderly and debilitated hospitalized patients. Previous research indicated a protective effect of ACE inhibitors (ACEi) on pneumonia risk but the literature lacks strength and is controversial. The objective of this study was to validate early findings of ACEi protective effect on pneumonia among elderly hospitalized patients.

METHODS: To assess the association between chronic ACEi and risk of pneumonia among elderly hospitalized patients without selected neurological disorders, a case-control study was conducted using data from University of Utah Data Warehouse. Inclusion criteria were hospitalized patients aged ≥65 years without ICD-diagnostic codes associated with dysphagia with a diagnosis of pneumonia between January 2012 and December 2016. Controls were propensity score matched to cases based on age, gender and Charlson’s Comorbidity Index. Patient records were reviewed for the use of ACEi 3 months, 6 months and 9 months prior to the admission date with estimations of risk of developing pneumonia. Odds ratios (OR) were calculated using multivariable conditional logistic regression. This data was used to validate our previous medical claims study of ACEi effect in a similar population from 2000-2002 from the Medstat MarketScan®/Medicare Supplemental and Coordination of Benefits.

RESULTS: The study population comprised 1,635 cases and 1,635 matched controls. After matching for confounders, chronic ACEi use was associated with a decreased risk of pneumonia (adjusted odds ratio (OR) 0.87 [95% confidence interval (CI) (0.84 – 0.89)]. The 2019 data compares favorably to 2000 claims data with chronic ACEi reduced pneumonia risk with an OR 0.71 [0.68-0.75].

CONCLUSIONS: Chronic ACE inhibitor use is associated with 13-29% lower risk of pneumonia in elderly hospitalized patients without neurological disorders affecting swallowing. These findings substantially add to the body of evidence about the effect of ACE inhibitors on pneumonia.