Early initiation of the antiviral oseltamivir (Tamiflu) reduces the risk for death in patients hospitalized with community-acquired pneumonia (CAP) but patients have to be tested for influenza first and that is not happening often enough, a large observational cohort of adult patients indicates.
“Early testing allows for early treatment, and we found that early treatment was associated with reduced mortality so testing patients during the flu season is crucial,” senior author Michael Rothberg, MD, MPH, of the Cleveland Clinic said in an interview.
“Even during the flu season, most patients with CAP in our study went untested for influenza [even though] those who received early oseltamivir exhibited lower 14-day in-hospital case fatality ... suggesting more widespread testing might improve patient outcomes,” the authors added.
The study was published online Feb. 5, 2022, in the journal CHEST.
Premier database
Data from the Premier Database – a hospital discharge database with information from over 600 hospitals in the United States – were analyzed between July 2010 and June 2015. Microbiological laboratory data was provided by 179 hospitals. “For each year, we evaluated the total percentage of patients tested for influenza A/B within 3 days of hospitalization,” lead author Abhishek Deshpande, MD, PhD, Cleveland Clinic, and colleagues explained.
A total of 166,268 patients with CAP were included in the study, among which only about one-quarter were tested for influenza. Some 11.5% tested positive for the flu, the authors noted. Testing did increase from 15.4% in 2010 to 35.6% in 2015 and it was higher at close to 29% during the influenza season, compared with only about 8% during the summer months.
Patients who were tested for influenza were younger at age 66.6 years, compared with untested patients, who were 70 years of age (P < .001). Tested patients were also less likely to have been admitted from a nursing facility (P < .001), were less likely to have been hospitalized in the preceding 6 months (P < .001) and have fewer comorbidities than those who were not tested (P < .001).
“Both groups had similar illness severities on admission,” the authors observed, “but patients who were tested were less likely to die in the hospital within 14 days,” the authors reported – at 6.7% versus 10.9% for untested patients (P < .001).
More than 80% of patients who tested positive for influenza received an antibacterial on day 1 of their admission, compared with virtually all those who were either not tested or who tested negative, the investigators added (P < .001). The mean duration of antibacterial therapy among patients with a bacterial coinfection was not influenced by influenza test results.
However, among those who tested positive for influenza, almost 60% received oseltamivir on day 1 whereas roughly 30% received treatment on day 2 or later. In fact, almost all patients who received early oseltamivir were tested for influenza on day 1, the investigators pointed out. Patients who received early oseltamivir had a 25% lower risk of death within the first 14 days in hospital at an adjusted odds ratio of 0.75 (95% confidence interval, 0.59-0.96).
Early initiation of the antiviral also reduced the risk of requiring subsequent ICU care by 36% at an aOR of 0.64; invasive mechanical ventilation by 46% at an aOR of 0.54, and the need for vasopressor therapy by 47% at an aOR of 0.53. All results were within the 95% confidence levels.
Early use of antiviral therapy also reduced both the length of hospital stay and the cost of that stay by 12%.