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Rating scales for heartburn (HB) studies
Author(s) -
Korn S.,
Villani M.,
Tipping R.,
Levine J. G.
Publication year - 2004
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1016/j.clpt.2003.11.213
Subject(s) - rating scale , placebo , likert scale , categorical variable , meal , heartburn , ordinal scale , medicine , statistics , psychology , mathematics , alternative medicine , disease , pathology , reflux
Categorical or VAS scales at fixed intervals after a provocative meal (PM) have been used to show H2‐receptor antagonists (H2RAs) prevent meal‐induced HB. We investigated measurement characteristics of a 10‐point ordinal rating (1= mildest ever through 10= worst ever) versus validated 4‐category Likert rating (none, mild, moderate, severe). Methods: Double‐blind parallel study with 282 HB‐sufferers randomized to take famotidine (fam) 20 or placebo before 4 self‐selected PMs eaten at home. HB intensity rated on 4‐point scale q30 minutes post‐meal for 3 hours, then maximum HB during the 3 hours rated on 10‐point scale (value of 0 assigned if no HB). Construct validity assessed using Spearman correlation (SC) between the scales. Discriminant validity assessed by comparing mean of 10‐point scale scores among groups of meal sessions with none, mild, moderate, or severe peak HB. Responsiveness between scales compared using effect size. Results: Peak HB with fam 20 significantly less than placebo according to periodic 4‐point and single 10‐point ratings. SC coefficient between scales was 0.943. Mean scores on 10‐point scale show clear distinction among categories for peak HB on 4‐point scale. Effect size with 10‐point scale (−0.249) was virtually identical to that with 4‐point scale (−0.252). Conclusion: Ability of single ordinal rating of peak HB to differentiate between treatments is similar to that seen with 4‐category Likert rating. Clinical Pharmacology & Therapeutics (2004) 75 , P56–P56; doi: 10.1016/j.clpt.2003.11.213