title: How cautious should we be when assessing apathy with the Unified Parkinson's Disease Rating Scale?
abstract: Current practice often assesses apathy with a single item from the Unified Parkinson's Disease Rating Scale (UPDRS, item 4). Yet, the relationship between the UPDRS item 4 and the validated Apathy Scale (AS) is unknown. The purpose of this study was to evaluate the operating characteristics of UPDRS item 4 in relation to the AS. Three hundred and one patients with PD were administered the AS and the UPDRS. We compared the UPDRS item 4 to the standard AS classification of > or =14 as apathetic. A receiver operating characteristics (ROC) curve was obtained, and sensitivity, specificity, positive, and negative predictive power were calculated. The ROC curve showed area under the curve as 0.75. A cut-off of 1 had good sensitivity (81%) but poor specificity (53%; high false positive rate). A cut-off point of 2 had acceptable specificity (87%) but poor sensitivity (52%, high false negative rate). Continuing to increasing the cut-off point (e.g., 3, 4) continues to increase specificity at the expense of dramatically reducing sensitivity. These findings suggest the use of caution when screening for apathy with item 4 due to its poor sensitivity in relation to the AS.
authors.affiliation: Department of Clinical and Health Psychology, College of Public Health and Health Professions, University of Florida, Gainesville, Florida 32610-0165, USA. lkirsch@phhp.ufl.edu
authors.forename: Lindsey
authors.initials: L
authors.lastname: Kirsch-Darrow
authors.forename: Laura B
authors.initials: LB
authors.lastname: Zahodne
authors.forename: Chris
authors.initials: C
authors.lastname: Hass
authors.forename: Ania
authors.initials: A
authors.lastname: Mikos
authors.forename: Michael S
authors.initials: MS
authors.lastname: Okun
authors.forename: Hubert H
authors.initials: HH
authors.lastname: Fernandez
authors.forename: Dawn
authors.initials: D
authors.lastname: Bowers
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000175:diagnosis* / Q000209:etiology*; D010300:Parkinson Disease / Q000150:complications* / Q000523:psychology*; D011569:Psychiatric Status Rating Scales; D012372:ROC Curve; D012680:Sensitivity and Specificity