Measurement
Stroke
Oral Presentation
Stephen Lau, BSOT
PhD student
Washington University School of Medicine in St. Louis
Saint Louis, Missouri
Mandy W.M. Fong, PhD
Instructor
Washington University School of Medicine in St. Louis
St. Louis , Missouri
Eric Lenze, MD
Professor of Psychiatry
Washington University School of Medicine
St.Louis, Missouri
Carolyn M. Baum, PhD, OTR/L, FAOTA
Professor of Occupational Therapy, Neurology and Social Work
Washington University School of Medicine
St.Louis, Missouri
Kenneth Ottenbacher, PhD, OTR, FACRM
Professor, Director
University of Texas Medical Branch
Galveston, Texas
Alex Wong, PhD, DPhil
Assistant Professor
Washington University School of Medicine
St. Louis, Missouri
We present evidence from a 1-year longitudinal study, using information from the Stroke Recovery in Underserved Population (SRUP) database, for the psychometrics of Center for Epidemiologic Studies Depression Scale (CES-D) in patients after stroke. This study included a sample of 828 adults, 55 years old and older with a first-time stroke, and admitted to one of eleven inpatient rehabilitation facilities in the United States. Confirmatory factor analyses indicated four-factor structure of the CES-D. Classical test theory and Rasch analyses further supported the reliability and validity of the CES-D. This measure allows investigators and clinicians to better characterize depressive symptoms in patients after stroke.
Objective:
To examine the psychometrics of the Center for Epidemiologic Studies Depression (CES-D) for patients after stroke using both classical test theory (CTT) and Rasch analyses.
Design:
A secondary data analysis of the Stroke Recovery in Underserved Population database (2005-2006), which was a prospective observational study with post-stroke patients.
Setting :
Eleven inpatient rehabilitation facilities located across diverse regions of the United States.
Participants (or Animals, Specimens, Cadavers):
Patients (N=828) who received inpatient stroke rehabilitation and had complete follow-up data were included in the analysis.
Interventions:
Not applicable.
Main Outcome Measure(s):
CES-D was administrated at discharge, 3-month, and 12-month follow-up.
Results:
Comparisons of competing models using confirmatory factor analyses indicated that the four-factor model (somatic symptoms, depressed affect, positive affect, and interpersonal difficulties) possessed the best model fit (CFI=0.98; TLI= 0.98; RMSEA=0.05). CTT analyses showed that the CES-D had satisfactory internal consistency (α=0.74-0.87). Rasch analyses supported the unidimensionality of each CES-D subscale with no misfit item. Rating scale analyses indicated the need to collapse response categories 2 and 3 of the somatic symptoms subscale. Reliability analyses indicated satisfactory item reliability but poor person separation of all subscales. A floor effect for persons and an uneven spread of items across the spectrum were observed. A total of 3 differential item functioning (DIF) items (depressed affect: 1; somatic symptoms: 2) across gender, and 1 DIF item (depressed affect: 1) across the time course of recovery were found but none of them reached practical relevance. All items of the somatic symptoms subscale indicated DIF across time.
Conclusions:
We confirmed the four-factor structure of the CES-D, supporting the use of four subscales to characterize depressive symptoms in patients after stroke. We verified the psychometrics of the CES-D and reported its DIF items. Other supplementary instruments are needed when comparing somatic symptoms across the time course of recovery.
