Supplemental Figure 1A: Funnel plots to assess publication bias

Supplemental Figure 1B: Funnel plot to assess publication bias excluding old studies (Eriksson et al. and Styrud et al.)

Supplemental Figure 2A: Antibiotics versus surgery for uncomplicated acute appendicitis: forest plot for the duration of pain (WMD >0 corresponds to larger values in the antibiotics group)

Supplemental Figure 2B: Antibiotics versus surgery for uncomplicated acute appendicitis: forest plot for the duration of sick leave (WMD >0 corresponds to larger values in the antibiotics group)

Supplemental Figure 2C: Antibiotics versus surgery for uncomplicated acute appendicitis: forest plot for the duration of time off work (WMD >0 corresponds to larger values in the antibiotics group)

Supplemental Figure 3A: Antibiotics failure subgroup versus surgery for uncomplicated acute appendicitis: forest plot for wound infection (RR >1 denotes outcome more frequently present in the antibiotics group)

Supplemental Figure 3B: Antibiotics failure subgroup versus surgery for uncomplicated acute appendicitis: forest plot for wound infection stratified by the reported antibiotic combination (RR >1 denotes outcome more frequently present in the antibiotics group)

Supplemental Figure 3C: Antibiotics failure subgroup versus surgery for uncomplicated acute appendicitis: forest plot for wound infection excluding the study by Hansson et al. (RR >1 denotes outcome more frequently present in the antibiotics group)

Supplemental Figure 3D: Antibiotics failure subgroup versus surgery for uncomplicated acute appendicitis: forest plot for wound infection excluding old studies (Eriksson et al. and Styrud et al.) (RR >1 denotes outcome more frequently present in the antibiotics group)

Supplemental Figure 4A: Antibiotics versus surgery for uncomplicated acute appendicitis: forest plot for treatment efficacy excluding the study by Hansson et al. (RR >1 denotes outcome more frequently present in the antibiotics group)

Supplemental Figure 4B: Antibiotics versus surgery for uncomplicated acute appendicitis: forest plot for treatment efficacy excluding old studies (Eriksson et al. and Styrud et al.) (RR >1 denotes outcome more frequently present in the antibiotics group)

Supplemental Figure 5A: Antibiotics failure subgroup versus surgery for uncomplicated acute appendicitis: forest plot for perforated appendicitis rates excluding the study by Hansson et al. (RR >1 denotes outcome more frequently present in the antibiotics group)

Supplemental Figure 5B: Antibiotics failure subgroup versus surgery for uncomplicated acute appendicitis: forest plot for perforated appendicitis rates excluding old studies (Eriksson et al. and Styrud et al.) (RR >1 denotes outcome more frequently present in the antibiotics group)

Supplemental Figure 6A: Antibiotics versus surgery for uncomplicated acute appendicitis: forest plot for hospital length of stay excluding the study by Hansson et al. (WMD >0 corresponds to larger values in the antibiotics group)

Supplemental Figure 6B: Antibiotics versus surgery for uncomplicated acute appendicitis: forest plot for hospital length of stay excluding old studies (Eriksson et al. and Styrud et al.) (WMD >0 corresponds to larger values in the antibiotics group)

Supplemental Figure 7A: Antibiotics versus surgery for uncomplicated acute appendicitis: forest plot for overall complications excluding the study by Hansson et al. (RR >1 denotes outcome more frequently present in the antibiotics group)

Supplemental Figure 7B: Antibiotics versus surgery for uncomplicated acute appendicitis: forest plot for overall complications excluding old studies (Eriksson et al. and Styrud et al.) (RR >1 denotes outcome more frequently present in the antibiotics group)

Supplemental Figure 8A: Antibiotics versus surgery for uncomplicated acute appendicitis: forest plot for perforated appendicitis rates excluding the study by Hansson et al. (RR >1 denotes outcome more frequently present in the antibiotics group)

Supplemental Figure 8B: Antibiotics versus surgery for uncomplicated acute appendicitis: forest plot for perforated appendicitis rates excluding old studies (Eriksson et al. and Styrud et al.) (RR >1 denotes outcome more frequently present in the antibiotics group)