Establishing Cut-off Points for the Cornell Scale to Enhance Depression Diagnosis in Parkinson's Disease Patients: A Study in the Vietnamese Healthcare Context.

Abstract

Background: Major Depressive Disorder (MDD) often coexists with Parkinson's Disease (PD), significantly affecting the quality of life. Depression in Parkinson's disease patients is frequently neglected due to an emphasis on motor symptoms, resulting in underdiagnosis. The Cornell Scale for Depression in Dementia (CS) demonstrates potential as a screening instrument for identifying depression in Parkinson's disease patients, while research on its use in Vietnam is scarce.

Aims: This study aims to calculate the Area Under the Receiver Operating Characteristic (AUROC) curve and identify optimal cut-off points for the CS in diagnosing depression in patients with Parkinson's disease.

Methods: In this cross-sectional study conducted at Nguyen Tri Phuong Hospital from February to September 2022, 54 patients with Parkinson's disease were examined for major depressive disorder according to DSM-5 criteria and evaluated using the CS. Reliability was assessed by inter-rater reliability testing. The diagnostic performance was assessed by calculating sensitivity, specificity, positive and negative predictive values, and the Area Under the Receiver Operating Characteristic (AUROC) curve.

Results: The CS exhibited significant reliability (Cronbach's alpha = 0.91; ICC = 0.91) and diagnostic precision (AUROC = 0.968). An ideal cut-off score of 9 was determined, exhibiting a sensitivity of 88.5% and a specificity of 89.3%. The results indicated cut-off scores of 6 and 11 for excluding or diagnosing depression, respectively, affirming the CS as a versatile and efficient screening instrument for patients with Parkinson's disease.

Conclusion: The CS is a dependable and valid screening tool for identifying depression in Vietnamese PD patients, enabling early detection and intervention.