Extensive influenza testing needed in pneumonia patients

Most patients with community-acquired pneumonia (CAP) go untested for influenza even during flu season, which is unfortunate since a positive test result facilitates antiviral therapy, and early treatment leads to lower mortality, according to a study.

Researchers evaluated influenza testing and compared antimicrobial utilization and outcomes of a positive, negative, and no test among 166,268 adult patients admitted with pneumonia in 2010–2015 to 179 hospitals in the US. They also examined potential relationships between early antiviral treatment with oseltamivir and 14-day in-hospital mortality, hospital length-of-stay (LOS), and cost.

Only 38,703 patients (23.3 percent of the population) underwent testing for influenza, of whom 11.5 percent tested positive. Testing jumped from 15.4 percent to 35.6 percent over 2010–2015 and was 28.9 percent during flu season (Oct–May) vs 8.2 percent in June–September.

Compared with those who tested negative, patients who turned out positive for influenza received antivirals more frequently and antibacterials less so, as well as shorter treatment courses (5.3 vs 6.4 days; p<0.001).

Influenza-positive patients who were initiated on oseltamivir at hospital day 1 (n=2,585) had lower 14-day in-hospital mortality (adjusted odds ratio, 0.75, 95 percent confidence interval [CI], 0.59–0.96), lower costs (adjusted ratio of means, 0.88, 95 percent CI, 0.81–0.95), and shorter LOS (adjusted ratio of means, 0.88, 95 percent CI, 0.84–0.93) than those who received oseltamivir later or not at all (n=1,742).

The results highlight the potential of more widespread influenza testing in improving outcomes for patients with CAP.