Validating the C-PHQ-9 suicide item against the C-NDDI-E for detecting suicidal ideation in Chinese adults with epilepsy.

BACKGROUND AND

OBJECTIVE

People with epilepsy (PWE) face a mortality risk from suicide that is roughly threefold higher than that of the general public; however, effective clinical screening for such risks remains a significant gap. Although depression acts as a primary indicator of suicidal ideation in this group, and while the Chinese versions of the Neurological Disorders Depression Inventory for Epilepsy (C-NDDI-E) and the Patient Health Questionnaire-9 (C-PHQ-9) are common self-report instruments, the specific diagnostic value of the C-PHQ-9's suicide-related item remains unverified in PWE. Furthermore, no direct comparative data exists. This study aimed to validate the diagnostic validity of the suicide component of the C-PHQ-9 in adult patients with epilepsy in Southeast China. The scale was validated against the MINI-SM and benchmarked against the C-NDDI-E to compare their diagnostic accuracy.

METHODS

Adult PWE were recruited from a tertiary epilepsy outpatient clinic. Assessments were conducted in a single session, where subjects first finalized the self- report scales (C-NDDI-E and C-PHQ-9) rafter undergoing the reference evaluation via the Mini-International Neuropsychiatric Interview suicide module (MINI-SM). Receiver operating characteristic (ROC) analyses were performed to assess diagnostic performance.

RESULTS

Among 321 participants, 45 (14.0 %) were identified as having suicidal ideation by the MINI-SM. The C-PHQ-9 suicide item showed moderate diagnostic performance (sensitivity 71.1 %, specificity 92.0 %, AUC 0.813), with an optimal cutoff of ≥1. In contrast, the C-NDDI-E suicide item demonstrated superior accuracy (sensitivity 86.7 %, specificity 90.6 %, AUC 0.891), with an optimal cutoff of ≥2. TheAUC of the C-NDDI- E item was significantly higher than that of the C-PHQ-9 item (P < 0.05).

CONCLUSION

Suicidal ideation is notably prevalent among adult PWE in Southeast China. Based on comparative outcomes, the C-NDDI-E suicide item demonstrates enhanced reliability over the C-PHQ-9, making it the preferable instrument for screening this specific demographic.