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