title: A comparison of the psychometric strengths of the public-domain Zung Self-rating Depression Scale with the proprietary Beck Depression Inventory-II in Barbados.
abstract: OBJECTIVE
  To compare the psychometric strengths of two venerable measures of depression, the Zung Self-rating Depression Scale (Zung SDS) and the Beck Depression Inventory-II (BDI-II) in a Caribbean university student population and to provide researchers and clinicians interested in measures of depression with psychometric evidence that differentiates the two instruments for a Caribbean sample.
  
  
  METHODS
  Undergraduate student volunteers (n = 415; 75% females, 25% males; mean age = 25.2 years) completed the instruments as part of a larger study. Correlational analyses evaluated internal con-sistency reliabilities. Missing value analyses and corrected item-total correlations are also reported for each scale.
  
  
  RESULTS
  The BDI-II demonstrated marginally superior internal consistency reliability (alpha = 0.88) than the Zung SDS (alpha = 0.85). Correlation between the Zung SDS and the BDI-II was strong (r = 0.67, p < 0.01). The Zung SDS was less psychometrically adequate, only 53% of respondents (compared to 81% for the BDI-II) completed the entire form, suggesting that the structure or wording of the questions may be problematic. Comparison of corrected item-total correlations and missing value analyses indicates that many Zung SDS items are problematic. A preliminary effort to evaluate the factor structure of the Zung SDS was complicated by the large number of missing values.
  
  
  CONCLUSIONS
  Head-to-head comparison of the Zung SDS and the BDI-II indicates that the BDI-II demonstrates superior psychometric properties. This paper does not evaluate sensitivity and specificity; nonetheless, researchers interested in measures of depressive symptoms and clinicians looking for a tool to assess depression in Barbados can be confident in the strong psychometric properties of the BDI-II demonstrated thus far Modified versions of the Zung SDS merit further research.
authors: Faculty of Medical Sciences, The University of the West Indies, Queen Elizabeth Hospital, Bridgetown, Barbados. dr.mike.campbell@gmail.com
authors: M H
authors: MH
authors: Campbell
authors: D
authors: D
authors: Maynard
authors: J W
authors: JW
authors: Roberti
authors: M K
authors: MK
authors: Emmanuel
mesh_terms: D000328:Adult; D001460:Barbados; D003863:Depression / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D012720:Severity of Illness Index; D013334:Students / Q000523:psychology