Comparative safety in terms of the incidence of ≥ grade 3 diarrhea between ICIs+EP (combined population of the treated groups of Atz+EP, Dur+EP, and Pem+EP) and EP, between ICIs+EP and IP, and between ICIs+EP and AP, for previously untreated ES-SCLC. Comparisons are shown as ICIs+EP vs. CT (EP, IP, or AP). Data are expressed as RR and 95% CrI. ICIs+EP, immune checkpoint inhibitors plus platinum–etoposide; Atz+EP, atezolizumab plus platinum–etoposide; Dur+EP, durvalumab plus platinum–etoposide; Pem+EP, pembrolizumab plus platinum–etoposide; EP, platinum–etoposide; IP, platinum–irinotecan; ES-SCLC, extensive-stage small cell lung cancer; CT, chemotherapy; RR, risk ratio; CrI, credible interval.