Jerome A Lindeboom1, Elisabeth S Bruijnesteijn van Coppenraet2, Ed J Kuijper2, Roger M Polsbroek3, Roy B Horsthuis3, Jan M Prins4, Robert Lindeboom5. 1. Department of Oral and Maxillofacial Surgery, Academic Medical Center, Amsterdam, The Netherlands; Academic Center for Dentistry (ACTA), University of Amsterdam, Amsterdam, The Netherlands. Electronic address: j.a.lindeboom@amc.uva.nl. 2. Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands. 3. Department of Oral and Maxillofacial Surgery, Academic Medical Center, Amsterdam, The Netherlands; Academic Center for Dentistry (ACTA), University of Amsterdam, Amsterdam, The Netherlands. 4. Department of Internal Medicine, Division of Infectious Diseases, Tropical Medicine and AIDS, Amsterdam, The Netherlands; Center of Infection and Immunity Amsterdam (CINIMA), Amsterdam, The Netherlands. 5. Department of Clinical Epidemiology, Biostatistics, and Bioinformatics, Academic Medical Center, Amsterdam, The Netherlands.
Abstract
OBJECTIVE: To apply Rasch measurement to develop a rule for clinical interpretation of the Observer Scar Assessment Scale (OSAS) to help surgeons judge reported sum scores clinically. STUDY DESIGN AND SETTING: We used cross-sectional data of a multicenter randomized clinical trial for the treatment of nontuberculous cervicofacial lymphadenitis in children. Rasch analysis was used on the OSAS scores obtained from scar photographs of 100 children after surgical or antibiotic treatment. RESULTS: Rasch analysis showed that all OSAS item rating scales needed revision and weighting. After doing so, raw scale scores could be converted into quantitative interval scale-based measures of scar quality. The clinical interpretation of the OSAS was clearly improved by the revised scoring. By using the Rasch-modeled item and person measures, the most likely OSAS score patterns associated with the revised OSAS sum scores could be determined. CONCLUSIONS: The Rasch analysis improved the measurement properties and clinical interpretability of the OSAS instrument.
RCT Entities:
OBJECTIVE: To apply Rasch measurement to develop a rule for clinical interpretation of the Observer Scar Assessment Scale (OSAS) to help surgeons judge reported sum scores clinically. STUDY DESIGN AND SETTING: We used cross-sectional data of a multicenter randomized clinical trial for the treatment of nontuberculous cervicofacial lymphadenitis in children. Rasch analysis was used on the OSAS scores obtained from scar photographs of 100 children after surgical or antibiotic treatment. RESULTS: Rasch analysis showed that all OSAS item rating scales needed revision and weighting. After doing so, raw scale scores could be converted into quantitative interval scale-based measures of scar quality. The clinical interpretation of the OSAS was clearly improved by the revised scoring. By using the Rasch-modeled item and person measures, the most likely OSAS score patterns associated with the revised OSAS sum scores could be determined. CONCLUSIONS: The Rasch analysis improved the measurement properties and clinical interpretability of the OSAS instrument.
Authors: Martijn B A van der Wal; Wim E Tuinebreijer; Monica C T Bloemen; Pauline D H M Verhaegen; Esther Middelkoop; Paul P M van Zuijlen Journal: Qual Life Res Date: 2011-05-20 Impact factor: 4.147
Authors: Eveline Bijlard; Reinier Timman; Gerda M Verduijn; Frank B Niessen; Johan W van Neck; Jan J V Busschbach; Marc A M Mureau Journal: Trials Date: 2013-12-19 Impact factor: 2.279