Drupal-Bibcite31<style face="normal" font="default" size="100%">Medications for chronic obstructive pulmonary disease: a historical non-interventional cohort study with validation against RCT results</style><style face="normal" font="default" size="100%">Medications for chronic obstructive pulmonary disease: a historical non-interventional cohort study with validation against RCT results</style>