Shorter antibiotic treatment durations may be as safe and effective as longer ones for a small subset of patients hospitalized with community-acquired pneumonia (CAP), researchers reported this week in the Annals of Internal Medicine.
For the study, a team led by researchers at the University of Michigan Medical School analyzed data from 67 Michigan hospitals from 2017 through 2024 to compare outcomes in hospitalized CAP patients with shorter versus longer antibiotic courses. The patients had to have received at least three days of antibiotics and to have achieved clinical stability by day 3.
Using an emulated target trial design, the researchers evaluated which CAP patients would qualify for short-course therapy, then compared 30-day all-cause mortality, hospital readmission, urgent care visits, and Clostridioides difficile infections in CAP patients who received 0 to one additional days of antibiotics (three to four days total) versus those who received two or more additional days (five or more days).
Only 10% of patients met eligibility criteria
Among the 55,517 patients hospitalized with CAP over the study period, only 5,620 (10.1%) met the eligibility criteria for short-course therapy, with most being excluded because of underlying comorbidities. The median age of eligible patients was 68.2 years, and 54.3% were men. Of those patients, only 7.9% received three-to-four days of antibiotics, and the median antibiotic duration was 7 days.
Thirty-day adjusted risk ratios for short- versus long-course antibiotic therapy were 0.89 for mortality, 1.07 for readmission, 0.94 for urgent visit, and 1.01 for C difficile infection. Adverse events were similar in both groups.
The study authors say the results are most applicable to non-intensive care unit CAP patients who are clinically stable after three days. But the study has identified critical research questions, they add.
“Given that 90% of patients were excluded, we need additional pragmatic, real-world data on the safety and efficacy of shorter antibiotic courses in higher-risk patients, such as those with more severe CAP, immunosuppression, multiple comorbidities, or persistent vital sign abnormalities,” they wrote.