Pneumonia mortality in a UK general practice population cohort

Background: Pneumonia is a common diagnosis in general practice in the United Kingdom and yet there is little known about the short- and long-term prognosis of people with a diagnosis of pneumonia in general practice. We investigated the short- and long-term survival of people with pneumonia diagnosed in general practice as compared to the general population for all ages. Methods: This was a general population-based cohort study. Data was obtained from a comprehensive general practice database called The Health Improvement Network (THIN) database which has computerized medical records from 300 general practice surgeries in the United Kingdom. We used Cox regression for our analyses. Results: For pneumonia cases the 30-day mortality was 18.5 and the 3-year mortality was 30.8. The equivalent figures for the general population controls were 0.4 and 10.3 respectively. The adjusted hazard ratio (HR) for all-cause mortality (for total follow-up time) in pneumonia cases vs. general population was 4.64 (95 CI 4.35-4.95). For the first 30 days the risk of mortality in cases was 46 times more (adj. HR 45.90, 95 CI 36.80-55.20). Even in the period of follow-up 91 days after diagnosis cases were almost 20 more likely to die compared to general population (adj. HR 1.19, 95 CI 1.08-1.31). Conclusion: People in general practice who have a diagnosis of pneumonia have a markedly increased mortality in the short-term but some increase in mortality persists during longer-term follow-up.