Background Hospital acquired pneumonia (HAP) is a common nosocomial condition, especially in the elderly population. We aimed to describe clinical and demographic features of patients diagnosed with HAP (excluding ventilator associated pneumonia) in a large teaching hospital and investigate the association of these features with 30 day mortality.

Methods We used electronic medical records to identify all individuals with a physician diagnosis of HAP between 1/11/2014 and 31/4/2015. We extracted information on demographics, radiographic and laboratory findings, antibiotic prescriptions and mortality. HAP was defined as either diagnosis of pneumonia after 48 h of admission or hospital admission within the preceding 10 days. 30 day mortality was defined as death within 30 days of first being prescribed antibiotics for HAP. Logistic regression was used to generate odds ratios for death at 30 days, stratified by clinical and demographic features. White cell count and C Reactive Protein (CRP) levels were divided into quartiles.

Results There were 790 people with a diagnosis of HAP during the study period. 396 (50.1%) were male and mean age at admission was 78.0 years (standard deviation [SD] 13.1). 56 (7.1%) people were admitted from a nursing home. 706 (89.4%) patients were admitted under medical specialities. 186 (23.5%) had a Charlson Index Score of 0, and 62 (7.9%) had dementia coded as a co-morbid illness. 48.9% of patients were reported to have consolidation on chest radiograph, whilst 19.9% were reported to have clear lungs. 598 (75.7%) patients had been admitted to hospital for at least 48 h prior to starting antibiotics for HAP, with a median stay of 5 days in hospital prior to starting antibiotics for HAP (Interquartile range [IQR]: 2 to 11). 240 (30.4%) patients died within 30 days of first being prescribed antibiotics for HAP. Features strongly associated with increased mortality at 30 days were older age, higher Charlson Index Score and high CRP (see Table 1).

Conclusion Our findings suggest that HAP poses a substantial burden to secondary care services and carries a high mortality rate.