title: Evaluating symptom outcomes in gastroparesis clinical trials: validity and responsiveness of the Gastroparesis Cardinal Symptom Index-Daily Diary (GCSI-DD).
abstract: BACKGROUND
  Patient-reported symptom scales are needed to evaluate treatments for gastroparesis. The Gastroparesis Cardinal Symptom Index-Daily Diary (GCSI-DD) was developed to assess daily symptoms of gastroparesis. This study evaluated the validity and responsiveness of the GCSI-DD in patients with gastroparesis.
  
  
  METHODS
  Symptomatic patients were started with a new treatment for gastroparesis. Patients completed the GCSI-DD each evening during a baseline week and for 8 weeks of treatment. Responders were defined based on patient and clinician global rating of change. Minimal important differences (MID) were estimated based on baseline to 4 week changes in symptoms scores for small improvements.
  
  
  RESULTS
  Of 69 patients participating, 46 had idiopathic, 19 diabetic, and four postfundoplication gastroparesis. Excellent test-retest reliability was seen for GCSI-DD scores, and there were significant correlations between GCSI-DD scores and clinician ratings of symptom severity. Responders to treatment reported improvements in nausea [effect size (ES) = 0.42, P < 0.001], postprandial fullness, ES = 0.83, P < 0.001), bloating (ES = 0.34, P < 0.001), early satiety (ES = 0.53, P < 0.001), but lower responses for upper abdominal pain (ES = 0.29), and vomiting (ES = 0.22; P = 0.119). MIDs were 0.55 for nausea, 0.97 for excessive fullness, 0.63 for bloating, 0.77 for postprandial fullness, and 0.30 for abdominal pain. A composite score of four symptoms (Composite-1; nausea, bloating, excessive fullness, postprandial fullness) had ES of 0.61 and MID of 0.73. Composite-2 score (nausea, early satiety, bloating, abdominal pain) had a lower ES of 0.47.
  
  
  CONCLUSIONS
  Symptoms of early satiety, nausea, postprandial fullness, and bloating were responsive to treatment for gastroparesis. A composite of these symptoms also demonstrates validity and responsiveness to treatment for gastroparesis, and may represent an acceptable endpoint for evaluating the effectiveness of medical treatments in clinical trials for gastroparesis.
authors.affiliation: United BioSource Corporation, Bethesda, MD 20814, USA. dennis.revicki@unitedbiosource.com
authors.forename: D A
authors.initials: DA
authors.lastname: Revicki
authors.forename: M
authors.initials: M
authors.lastname: Camilleri
authors.forename: B
authors.initials: B
authors.lastname: Kuo
authors.forename: L A
authors.initials: LA
authors.lastname: Szarka
authors.forename: J
authors.initials: J
authors.lastname: McCormack
authors.forename: H P
authors.initials: HP
authors.lastname: Parkman
mesh_terms: D015746:Abdominal Pain / Q000453:epidemiology; D000293:Adolescent; D000328:Adult; D000368:Aged; D002986:Clinical Trials as Topic; D004185:Disability Evaluation; D004599:Electric Stimulation Therapy; D005260:Female; D018662:Fundoplication; D018589:Gastroparesis / Q000188:drug therapy / Q000628:therapy*; D006801:Humans; D008297:Male; D008499:Medical Records / Q000706:statistics & numerical data*; D008875:Middle Aged; D009325:Nausea / Q000209:etiology / Q000628:therapy; D018579:Patient Selection; D019518:Postprandial Period; D011788:Quality of Life; D015203:Reproducibility of Results; D012528:Satiety Response / Q000502:physiology; D016896:Treatment Outcome; D014839:Vomiting / Q000453:epidemiology; D055815:Young Adult