Psychometric properties of Spanish version of QIDS-SR16 in depressive patients

Depression is a worldwide health problem. Thus, making the diagnosis with reliable and short tests is crucial. In this regard, the Quick Inventory of Depressive Symptomatology-Self Report (QIDS-SR16) has been validated in several countries. It was found that this instrument has a correct balance between time and reliability. This study has aimed to assess psychometric properties of QIDS-SR16 Spanish version, and to calculate several cutoffs to evaluate the depressive disorder severity.

The study was based on the data from the RESIST study that recruited 1595 depressive patients from 17 regional communities. Instruments used were Hamilton Depression Rating Scale (HDRS17) and Spanish version of QIDS-SR16. Statistical analyses included test-retest reliability and internal consistency calculation, and exploratory factor analysis. In addition, ROC curve was calculated in order to determine different cutoff values.

QIDS-SR16 shows adequate test-retest reliability and high internal consistency (α=0.871), as well as ROC value of 0.946. Exploratory factor analysis showed a one factor model, which accounted for 46.80% of variance. Convergent validity and sensitivity to change were adequate.

The results suggest that the QIDS-SR16 is a reliable test to assess depressive symptom severity in the Spanish population. The cutoff that shows the best sensitivity/specificity rate was a total score of 7.