Toronto, June 12 (IANS): Having had community-acquired pneumonia (CAP) greatly increases the risk of long-term morbidity and mortality compared to those who have never had CAP, shows a Canadian study.

This was the longest and largest outcome from the study of patients with CAP reported till date.

"In our large population-based study of more than 6,000 adults with CAP and almost 30,000 matched controls, we found that CAP patients have high rates of long-term morbidity and mortality compared to those who have never had CAP, irrespective of their age," said Dean T. Eurich of the University of Alberta in Edmonton, at Alberta in Canada.

The study was published online in the American Journal of Respiratory and Critical Care Medicine.

During the follow-up, 2,858 CAP patients died, an absolute risk difference of 30 excess deaths per 1,000 patient years of follow-up and a greater rate of mortality among CAP patients.

Young CAP patients under 25 had the lowest absolute risk difference for mortality.

Those over 80 years had the highest absolute risk difference.

Apart from the increased mortality risk, the rates of all-cause hospitalization, emergency department visits, and CAP-related hospital visits, were all significantly higher in CAP patients compared to controls.

"Indeed CAP is still considered 'the old man's friend' because of the almost assured high mortality; however our results lend strong support to the alternate proposition that CAP ought to also be considered the young adult's adversary," Eurich explained.

"Future research may help explain the factors underling these increased long-term risks in CAP patients and inform a treatment approach in these patients," Eurich concluded.