Letter: Impact of Suboptimal Peak Inspiratory Flow on Exacerbations in Chronic Obstructive Pulmonary Disease Patients Using Dry Powder Inhalers. - Moon JY; Kim SH; Kim Y; Lee H; Rhee CK; Ra SW; Lee CY; Park JH; Park YB; Yoo KH (Journal of aerosol medicine and pulmonary drug delivery, 2026)