Eight RCTs were included in the review with 660 participants.
The use of antibiotics decreased the duration of cough and sputum production by approximately one-half day (summary ES 0.21, 95% CI: 0.05, 0.36).
For specific symptoms reported by at least four studies, there were nonsignificant trends favouring the use of antibiotics of a decrease of 0.4 days of purulent sputum (95% CI: -0.1, 0.8), a decrease of 0.5 days of cough (95% CI: -0.1, 1.1) and a decrease of 0.3 days lost from work (95% CI: -0.6, 1.1).
A test for heterogeneity was not significant for the overall summary ES (P = 0.37) or for days of sputum production (P = 0.50). A test for heterogeneity was significant for the summary mean difference for days lost from work (P = 0.03) and days of cough (P = 0.05), suggesting that these outcomes may have been derived from studies that used different methods. There was no correlation between study size and overall effect size r = -0.13, P = 0.75).