Systematic Review and Meta-analysis of the Efficacy of Short-Course Antibiotic Treatments for Community-Acquired Pneumonia in Adults

The duration of therapy for community-acquired pneumonia (CAP) remains undefined. We sought to investigate whether short-course antibiotic treatment for CAP is associated with favorable clinical outcomes in adult patients. We systematically searched PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov for studies comparing the effectiveness and safety between treatment regimens administered for <= 6 days and >= 7 days. We defined treatment for <= 6 days as short-course treatment and treatment for >= 7 days as long-course treatment. Twenty-one clinical trials (4,861 clinically evaluable patients) were included, and 19 out of 21 trials were randomized. Clinical cure was similar between the compared groups (4,069 patients, risk ratio [RR] = 0.99 [95% confidence interval {CI}, 0.97 to 1.01]), irrespective of patient setting (RR = 0.98 [95% CI, 0.96 to 1.00] for the outpatient setting and RR = 1.00 [95% CI, 0.92 to 1.09] for the inpatient setting) or severity of pneumonia (RR = 1.05 [95% CI, 0.96 to 1.14]). Also, relapses were similar between the short-and long-course treatment groups (1,923 patients, RR = 0.67 [95% CI, 0.30 to 1.46]). Short-course treatment was associated with fewer serious adverse events (1,923 patients, RR = 0.73 [95% CI, 0.55 to 0.97]) and, importantly, resulted in lower mortality than long-course treatment (2,802 patients, RR = 0.52 [95% CI, 0.33 to 0.82]). In CAP, short-course antibiotic treatment (<= 6 days) is as effective as and potentially superior to, in terms of mortality and serious adverse events, longer-course treatment.