Donald M Bushnell1, Kelly P McCarrier2, Elizabeth Nicole Bush3, Lucy Abraham4, Carol Jamieson5, Fiona McDougall6, Madhukar H Trivedi7, Michael E Thase8, Linda Carpenter9, Stephen Joel Coons10. 1. Evidera, Seattle, WA, USA. Electronic address: don.bushnell@evidera.com. 2. Patient-Reported Outcomes and Clinical Outcomes Assessment Center of Excellence, Pharmerit International, Seattle, WA, USA. 3. Global Patient-Focused Outcomes Center, Eli Lilly and Company, Indianapolis, IN, USA. 4. Pfizer Ltd, Tadworth, Surrey, UK. 5. Global Commercial Strategy Organization, Janssen Global Services, LLC, Fremont, CA, USA. 6. PCOR Neurosciences, Roche UK, Welwyn Garden City, UK. 7. Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA. 8. Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA. 9. Brown University, Providence, RI, USA. 10. Critical Path Institute, Patient-Reported Outcome Consortium, Tucson, AZ, USA.
Abstract
BACKGROUND: The Symptoms of Major Depressive Disorder Scale (SMDDS) was expressly developed on the basis of qualitative data to directly incorporate patients' voices into evaluation of treatment benefit in major depressive disorder (MDD) clinical trials. OBJECTIVES: To collect quantitative data necessary to refine/optimize the SMDDS and document its psychometric properties. METHODS: In this multicenter, observational study, participants with clinically diagnosed MDD completed questionnaires in 2 waves. Wave 1 was designed to refine the SMDDS using Rasch measurement evaluations and item reduction analyses. On a subset of wave 1 subjects, 7 to 12 months later, wave 2 further examined item performance and measurement properties. Exploratory factor analyses and assessments of construct validity and reliability (internal consistency and reproducibility) were completed. RESULTS: Using wave 1 data (N = 315; females = 71%, white = 81%, mean age = 44 years), the SMDDS was revised from 36 to 16 items. The Rasch item threshold map indicated that all but 1 item (suicidal ideation) were appropriately ordered. The 207 wave 2 participants were 74% females, 82% white, with a mean age of 45 years. The exploratory factor analyses resulted in a single component (all standardized factor loadings >0.46). Cronbach α was 0.93 and the 7-day test-retest intraclass correlation coefficient (n = 93) was 0.84 (95% confidence interval 0.77-0.89). SMDDS scores discriminated between MDD severity levels. CONCLUSIONS: The 16-item SMDDS generated highly reliable scores with substantial evidence of construct validity. On the basis of the evidence of appropriate content validity and sound psychometric performance, the Food and Drug Administration qualified the SMDDS as an outcome measure to support exploratory efficacy endpoints in MDD clinical trials.
BACKGROUND: The Symptoms of Major Depressive Disorder Scale (SMDDS) was expressly developed on the basis of qualitative data to directly incorporate patients' voices into evaluation of treatment benefit in major depressive disorder (MDD) clinical trials. OBJECTIVES: To collect quantitative data necessary to refine/optimize the SMDDS and document its psychometric properties. METHODS: In this multicenter, observational study, participants with clinically diagnosed MDD completed questionnaires in 2 waves. Wave 1 was designed to refine the SMDDS using Rasch measurement evaluations and item reduction analyses. On a subset of wave 1 subjects, 7 to 12 months later, wave 2 further examined item performance and measurement properties. Exploratory factor analyses and assessments of construct validity and reliability (internal consistency and reproducibility) were completed. RESULTS: Using wave 1 data (N = 315; females = 71%, white = 81%, mean age = 44 years), the SMDDS was revised from 36 to 16 items. The Rasch item threshold map indicated that all but 1 item (suicidal ideation) were appropriately ordered. The 207 wave 2participants were 74% females, 82% white, with a mean age of 45 years. The exploratory factor analyses resulted in a single component (all standardized factor loadings >0.46). Cronbach α was 0.93 and the 7-day test-retest intraclass correlation coefficient (n = 93) was 0.84 (95% confidence interval 0.77-0.89). SMDDS scores discriminated between MDD severity levels. CONCLUSIONS: The 16-item SMDDS generated highly reliable scores with substantial evidence of construct validity. On the basis of the evidence of appropriate content validity and sound psychometric performance, the Food and Drug Administration qualified the SMDDS as an outcome measure to support exploratory efficacy endpoints in MDD clinical trials.
Authors: Sonya Eremenco; Wen-Hung Chen; Steven I Blum; Elizabeth Nicole Bush; Donald M Bushnell; Kendra DeBusk; Adam Gater; Linda Nelsen; Stephen Joel Coons Journal: Qual Life Res Date: 2022-07-19 Impact factor: 3.440
Authors: Jennifer Voelker; Kun Wang; Wenze Tang; Jinghua He; Ella Daly; Christopher D Pericone; John J Sheehan Journal: BMC Psychiatry Date: 2021-05-17 Impact factor: 3.630