Reliability and validity of the Chinese version of the Patient Health Questionnaire 9 (C-PHQ-9) in patients with epilepsy

Objective: The aim of this study was to evaluate the clinical reliability and validity of the Chinese version of the Patient Health Questionnaire 9 (C-PHQ-9) in patients with epilepsy.

Methods: A total of 213 consecutive adult patients with epilepsy were evaluated. Receiver operating characteristic (ROC) analysis was performed using C-PHQ-9 and Chinese version of Patient Health Questionnaire 2 (C-PHQ-2) as predictors and the Mini International Neuropsychiatric Interview Plus Version 5.0.0 as the gold standard.

Results: The C-PHQ-9 was easily understood and quickly finished by the patients. According to the gold standard, the prevalence of current major depressive disorder in this population was 16.4%. Cronbach's α coefficient for the C-PHQ-9 was 0.860. The ROC analysis showed an area under the curve (AUC) of 0.888 (95% confidence interval [CI] = 0.838-0.927). At a cutoff score of >6, the C-PHQ-9 had a sensitivity of 82.86%, a specificity of 84.27%, a positive predictive value of 50.9%, and a negative predictive value of 96.2%. The C-PHQ-2 at a cutoff score of >1 resulted in the greatest balance of sensitivity and specificity (77.14% and 75.28%, respectively).

Conclusion: Our findings support a high reliability and validity for the C-PHQ-9 as a screening tool for the detection of current major depression in Chinese patients with epilepsy.