Validating Scoring Criteria for Parkinson’s Disease Psychosis

According to research published in the American Journal of Geriatric Psychiatry, the National Institute of Neurological Disorders and Stroke (NINDS) criteria shows good reliability for scoring symptoms of Parkinson’s disease (PD) psychosis (2017;25[1]:73-80). 

Due to the lack of validated diagnostic tools for PD psychosis, researchers led by Pedro Caldana Gordon, MD, MSc, Hospital Santa Marcelina (São Paulo, Brazil), aimed to verify the validity of the proposed NINDS criteria and explore its possible applications in clinical practice.

Participants (n = 104) with idiopathic PD referred to a movement disorder clinic were prospectively chosen for a cross-sectional evaluation; the evaluation confirmed idiopathic PD and classified PD psychosis according to the NINDS criteria. A psychiatrist then classified the participant according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria for psychosis.

Researchers found that, of the total sample of participants, 52 (50%) met the proposed criteria for NINDS PD psychosis and 16 (15.6%) met the standard criteria. Inter-rater reliability scoring showed only fair agreement between the two sets of criteria (κ = 0.30). However, after using a scoring approach for each NINDS criteria item and a cutoff total score for the diagnosis of PD psychosis, the agreement between the criteria significantly increased (κ = 0.72), with sensitivity and specificity above 90%.

Ultimately, although the NINDS criteria had limited reliability for diagnosing PD psychosis, Dr Gordon and his team felt the scoring approach could be an effective strategy for identifying patients with PD psychosis. —Amanda Del Signore