title: Tiotropium in combination with placebo, salmeterol, or fluticasone salmeterol for chronic obstructive pulmonary disease: possible confounding effect of treatment withdrawal?
authors: Samuel M
authors: SM
authors: Brown
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000318:Adrenergic beta-Agonists / Q000627:therapeutic use; D000420:Albuterol / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000730:Androstadienes / Q000627:therapeutic use*; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D015986:Confounding Factors, Epidemiologic; D004359:Drug Therapy, Combination; D000068298:Fluticasone; D006801:Humans; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy*; D000068299:Salmeterol Xinafoate; D028761:Withholding Treatment
chemical_list: D000305:Adrenal Cortex Hormones; D000318:Adrenergic beta-Agonists; D000730:Androstadienes; D001993:Bronchodilator Agents; D000068299:Salmeterol Xinafoate; D000068298:Fluticasone; D000420:Albuterol