Validation of Item 4 of the Neurological disorders depression Inventory for epilepsy as a rapid screening tool for suicidality in Russian persons with epilepsy

Abstract

Background

Suicide rates among persons with epilepsy (PWE) are high and a reliable and valid tool to screen for suicidality in this population is needed. The aim of this study is to validate the Russian version of the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E) Item 4 as a screening tool for suicidality in PWE.

Methods

A consecutive sample of the Russian PWE has completed the NDDI-E. The Columbia Suicide Severity Rating Scale (C-SSRS) was used as the gold standard for assessing suicide risk. Statistical methods used were Fisher’s exact test, Mann-Whitney test and Benjamini-Hochberg procedure. Item 4 characteristics for suicide screening were evaluated using receiver operating characteristics (ROC) analysis, and the maximum value of Youden’s index (J) was used to select the optimal cut-off point.

Results

A total of 372 PWE were enrolled (mean age 42.9 years, 64.8 % female), of whom 42 (11.3 %) were at risk for suicide. The area under the curve (AUC) for Item 4 in identifying suicide risk was 0.86 and the optimal cut-off for Item 4 was > 1 (J = 0.661). At this cut-off, Item 4 had a sensitivity of 80.9 %, a specificity of 85.1 %, a positive predictive value (PPV) of 41.0 % and a negative predictive value (NPV) of 97.2 %.

Conclusion

Item 4 of the Russian version of the NDDI-E (with a cut-off of > 1) is a reliable and valid tool for screening suicidality in PWE. It has good psychometric properties, is not time-consuming, and could therefore be recommended for routine use in settings providing medical care to Russian-speaking PWE.