title: Response to Ringbaek et al.
authors.forename: S
authors.initials: S
authors.lastname: Lanes
mesh_terms: D001993:Bronchodilator Agents / Q000009:adverse effects*; D006801:Humans; D009241:Ipratropium / Q000009:adverse effects*; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000401:mortality; D012307:Risk Factors
chemical_list: D001993:Bronchodilator Agents; D009241:Ipratropium