Study Participants
The study was conducted in the department of respiratory medicine, Chettinad Hospital. Thirty patients with obstructive pulmonary diseases who attend outpatient services at the department of respiratory medicine between August 2019 to March 2020 were enrolled in the study. Inclusion criteria for the study: diagnosis of COPD by the physician, prescribed to take salbutamol through metered-dose inhaler salbutamol at least for the previous 12 months. Patients who were using other inhaler devices other than MDI and those who do not have to follow up details at least for the previous 12 months were excluded. All eligible patients were enrolled in the study after obtaining informed consent.