A validation of a self-administered screening test for Parkinson's disease

Background: The detection and diagnosis of Parkinson's disease (PD) is of paramount importance for optimal treatment and for participation in disease-modifying trials. The present study assesses the diagnostic accuracy of the Baylor Functional Assessment Scale (BFAS), a self-administered screening instrument, designed to distinguish between patients with PD, other disorders (OD), and healthy controls (HC). Methods: Using the BFAS, we screened a total of 265 individuals including patients diagnosed at the Baylor College of Medicine Parkinson's Disease Center and Movement Disorders Clinic (PDCMDC) with PD (N = 63) and with OD (N = 47), and HC (N = 155) participants recruited from the PDCMDC and community health fairs. Results: Significant group differences in BFAS total scores were found (F = 172.6; p < 0.001) between patients with PD and those with OD and both groups endorsed more items than the HC group. A cut-point of 3 on the BFAS total score maximized the sensitivity (85.7%, 95%CI: 74.61% to 93.25%) and the specificity (87.7%, 05% Ci: 81.52% to 92.46%) for distinguishing PD from HC with a negative predictive value (NPV) of 93.8% and a negative likelihood ratio (NLR) of 0.16. At a cut-point of 5, the BFAS maximized sensitivity (76%, 95% CI: 63.79% to 86.02%) and specificity (72%, 95% CI: 57.36% to 84.38%) for distinguishing PD from OD with a NPV of 69.4% and a NLR of 0.33. Conclusions: In this pilot study, the BFAS provides a sensitive and specific screening tool for PD that helps differentiate individuals with PD from HC and from those with other disorders. Through future validation studies, the BFAS may be a useful instrument for identifying individuals with PD and for recruitment into PD clinical trials.