A Cochrane Review of nine randomized, con- trolled trials of antibiotic agents (including three trials not included in the previous review31) also
showed a significant but minor reduction in the duration of cough (0.6 day).33 There was a nonsig- nificant reduction in the number of days of feel- ing ill and a nonsignificant increase in adverse events attributed to antibiotics (relative risk of adverse events, 1.22; 95% confidence interval, 0.94 to 1.58).