While community-acquired pneumonia (CAP) causes “considerable morbidity and mortality” in the short-term, few studies have examined its long-term consequences.

Now a new study reports that CAP increases long-term mortality by 65 per cent. Researchers enrolled 6,078 adults with CAP from six hospitals and seven emergency departments in Canada. They matched each patient with up to five controls.

The average age was 59 years, with 44 per cent at least 65 years of age. Fifty-three per cent were male. During a median follow-up of 9.8 years, 2,858 CAP patients died – an absolute increase of 30 deaths per 1,000 patient years compared to controls.

After allowing for confounders, people who had a CAP episode were 65 per cent more likely to die during follow-up. Absolute mortality was consistently higher among CAP patients compared to controls after one year (124 and 63 per 1,000 patient years respectively), one to five years (71 and 36 respectively), five to nine years (53 and 34 respectively) and at least 10 years (42 and 34 respectively). 

CAP patients less than 25 years of age had the lowest absolute difference in mortality (four per 1,000 patient years, hazard ratio 2.40). Patients over 80 years had the highest (92 per 1,000 patient years, hazard ratio 1.42).

CAP patients were more likely to be hospitalised and visit emergency departments and showed a nearly four-fold absolute increase in subsequent CAP-related events. (Am J Resp Crit Care Med DOI:10.1164/ rccm.201501- 0140OC)