Factors Associated With the Development of Bacterial Pneumonia Related to Seasonal Influenza Virus Infection: A Study Using a Large-scale Health Insurance Claim Database. - Shirata, Masahiro; Ito, Isao; Jo, Taisuke; Iwao, Tomohide; Oi, Issei; Hamao, Nobuyoshi; Nishioka, Kensuke; Yamana, Hayato; Nagase, Takahide; Yasunaga, Hideo; Hirai, Toyohiro (Open Forum Infectious Diseases, 2023)