Correction to: Effect of timing of bronchodilator therapy initiation on exacerbations in patients with chronic obstructive pulmonary disease: a retrospective cohort study - Hideyasu Yamada; Isao Matsumoto; Naoyuki Makita; Yoshifumi Arita; Nobuya Hayashi; Kurena Mitsuoka; Naoki Tashiro; Nobuyuki Hizawa (Respiratory Research, 2022)