TY - JOUR
T1 - Symptoms of Major Depressive Disorder Scale
T2 - Performance of a Novel Patient-Reported Symptom Measure
AU - PRO Consortium's Depression Working Group
AU - Bushnell, Donald M.
AU - McCarrier, Kelly P.
AU - Bush, Elizabeth Nicole
AU - Abraham, Lucy
AU - Jamieson, Carol
AU - McDougall, Fiona
AU - Trivedi, Madhukar H.
AU - Thase, Michael E.
AU - Carpenter, Linda
AU - Coons, Stephen Joel
N1 - Publisher Copyright:
© 2019 ISPOR–The Professional Society for Health Economics and Outcomes Research
PY - 2019/8
Y1 - 2019/8
N2 - 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.
AB - 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.
KW - content validity
KW - depression
KW - major depressive disorder
KW - patient-reported symptom measure
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U2 - 10.1016/j.jval.2019.02.010
DO - 10.1016/j.jval.2019.02.010
M3 - Article
C2 - 31426932
AN - SCOPUS:85070723030
SN - 1098-3015
VL - 22
SP - 906
EP - 915
JO - Value in Health
JF - Value in Health
IS - 8
ER -