The internal and external validity of the Major Depression Inventory in measuring severity of depressive states

• DOI: 10.1017/s0033291702006724
• Publication Date: 2003-02-14T11:14:28Z
• Authors: L. R. OLSEN; D. V. JENSEN; V. NOERHOLM; K. MARTINY; P. BECH
• Keywords: External validity; Depression; Internal validity; Statistic

Background. We have developed the Major Depression Inventory (MDI), consisting of 10 items, covering DSM-IV as well ICD-10 symptoms depressive illness. aimed to evaluate this a scale measuring severity states with reference both internal and external validity. Method. Patients representing score range from no depression marked on Hamilton Scale (HAM-D) completed MDI. Both classical modern psychometric methods were applied for evaluation validity, including Rasch analysis. Results. In total, 91 patients included. The results showed that MDI had an adequate validity in being unidimensional (the total appropriate or sufficient statistic). was also confirmed correlated significantly HAM-D (Pearson's coefficient 0·86, P [les ]0·01, Spearman 0·80, ]0·01). Conclusion. When used sample different has