Determination of the Minimal Important Difference for the Acute Otitis Media Severity of Symptom Scale

作者：Shaikh Nader^*; Rockeue Howard E; Hoberman Alejandro; Kurs Lasky Marcia; Paradise Jack L

来源：Pediatric Infectious Disease Journal, 2015, 34(3): E41-E43.

DOI：10.1097/INF.0000000000000557

• acute otitis media
• severity of symptoms
• patient-reported outcome
• minimally important difference

Background: We previously developed and validated the acute otitis media severity of symptom (AOM-SOS) scale for rating symptoms of AOM in young children. In this report, we sought to estimate the minimal important difference (MID) for change in AOM-SOS scores.
Methods: In a group of children 6-24 months of age with AOM enrolled in a recently reported placebo-controlled clinical trial of antibiotic efficacy, we compared changes in AOM-SOS scores with parental assessments of change over a 24-hour period. Mean absolute and mean relative change in scores in children reportedly exhibiting only a small degree of improvement were considered in arriving at an estimated MID. We then compared the proportions of children in the antibiotic and placebo groups, respectively, whose AOM-SOS scores changed more than the estimated MID at various time points after enrollment.
Results: Data were available for 277 children. Children whose parents reported only a small degree of improvement 24 hours after enrollment had a mean decrease in AOM-SOS score of 3.8, or 55%, from baseline. We found the relative decrease more telling than the absolute decrease. The proportions of children in the antibiotic and placebo groups, respectively, whose AOM-SOS scores had decreased <55% on Day 7 were 12.3 and 23.8% (P = 0.02), and during Days 4-7 were 28 and 40% (P = 0.046).
Conclusions: We estimated the MID for change in AOM-SOS scores in young children and described use of the MID as an added metric in interpreting results from a clinical trial of antibiotic efficacy.

• 出版日期2015-3