title: The problem of placebo-controlled trials allowing rescue medication: how to assess efficacy in rhinosinusitis and allergic rhinoconjunctivitis when both groups receive active rescue treatment.
abstract: OBJECTIVE
  The assessment of pharmacological efficacy of rhinosinusitis and rhinoconjunctivitis has been performed in various studies involving standardized measures such as symptom scores, various health-related quality of life scales, the sino-nasal outcome test, or the rhinoconjunctivitis quality of life questionnaire. However, the methods and study designs are heterogeneous, and a methodological standard is still lacking. The aim of this review was--from a clinical and a methodological point of view--to evaluate placebo-controlled trials permitting the use of rescue medication and to provide insight into the specific challenges of such clinical trials. Using studies published within the past 24 months as examples, we here demonstrate the problems in evaluating and interpreting these studies and describe possibilities for refining the methodology in order to improve future study designs.
  
  
  RESULTS
  The World Allergy Organization has recently published recommendations for the standardization of clinical trials on respiratory allergy in which methodological aspects regarding the use of rescue medication are discussed.
  
  
  CONCLUSIONS
  This study summarizes the recommendations for study design, outcome measures, and statistical analysis to be used in planning, performing, and analyzing clinical studies on rhinoconjunctivitis and rhinosinusitis that allow the use of rescue medication.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital of Cologne, Germany. Julia.Vent@uk-koeln.de
authors.forename: Julia
authors.initials: J
authors.lastname: Vent
authors.forename: Walter
authors.initials: W
authors.lastname: Lehmacher
mesh_terms: D018926:Anti-Allergic Agents / Q000008:administration & dosage*; D003233:Conjunctivitis, Allergic / Q000188:drug therapy*; D018849:Controlled Clinical Trials as Topic / Q000592:standards*; D006801:Humans; D018579:Patient Selection; D010919:Placebos; D017410:Practice Guidelines as Topic; D012221:Rhinitis, Allergic, Perennial / Q000188:drug therapy*; D006255:Rhinitis, Allergic, Seasonal / Q000188:drug therapy*; D012852:Sinusitis / Q000188:drug therapy*; D016896:Treatment Outcome
chemical_list: D018926:Anti-Allergic Agents; D010919:Placebos