title: Effect of common comparators in indirect comparison analysis of the effectiveness of different inhaled corticosteroids in the treatment of asthma.
abstract: OBJECTIVE
  Indirect comparison (IC) and direct comparison (DC) of four inhaled corticosteroid (CS) treatments for asthma were conducted, and the factors that may influence the results of IC were investigated. Among those factors, we focused on the effect of common comparator selection in the treatment of asthma, where little control group bias or placebo effect is expected.
  
  
  METHODS
  IC and DC were conducted using the change from baseline in forced expiratory volume in 1 s (FEV1(L)) as an outcome parameter. Differences between inhaled CS were evaluated to compare the results of IC and DC. As a common comparator for IC, placebo (PLB) or mometasone (MOM) was selected. Whether the results of IC are affected by the selection of a common comparator and whether the results of IC and DC are consistent were examined.
  
  
  RESULTS
  23 articles were identified by a literature search. Our results showed that ICs yielded results similar to DCs in the change from baseline of FEV1(L). No statistically significant difference was observed in inconsistency analysis between ICs and DCs. It was clinically and statistically confirmed that ICs with PLB and those with MOM did not differ in terms of the results of FEV1(L) analysis in this dataset.
  
  
  CONCLUSIONS
  This study demonstrated that ICs among inhaled CS can deliver results consistent with those of DCs when using the change from baseline in FEV1(L) as an outcome parameter in asthma patients. It was also shown that using an active comparator has similar results if there is no effect of control group bias. It should be emphasized that the investigation of control group bias is a key factor in conducting relevant ICs so that an appropriate common comparator can be selected.
authors: Faculty of Pharmacy, Keio University, Tokyo, Japan; Development and Medical Affairs Division, GlaxoSmithKline K.K., Tokyo, Japan.
authors: Taro
authors: T
authors: Kunitomi
authors: Faculty of Pharmacy, Keio University, Tokyo, Japan.
authors: Masayuki
authors: M
authors: Hashiguchi
authors: Faculty of Pharmacy, Keio University, Tokyo, Japan.
authors: Mayumi
authors: M
authors: Mochizuki
mesh_terms: D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use*; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology; D019992:Databases as Topic; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D000068656:Mometasone Furoate / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D010919:Placebos; D016896:Treatment Outcome
chemical_list: D000305:Adrenal Cortex Hormones; D018927:Anti-Asthmatic Agents; D010919:Placebos; D000068656:Mometasone Furoate