Improved, But Still Suboptimal Validity in Criteria for Prodromal Parkinson Disease

A study to validate the recent research criteria for identifying prodromal Parkinson disease (pPD) with updated criteria found slight increased, but still suboptimal sensitivityfor pPD.

In the study, there was no event where a person with PD or dementia with Lewy bodies (DLB) had probable pPD at baseline (ie, ≥80% pPD probability). Using 10%, 30%, and 50% probability cut-offs for  possible pPD, sensitivity and specificity ranged from 4.5% to 27.3%, and 85.7% to 98.3%, reflecting a slight increase in sensitivity. The area under the curve was 0.691 (95% CI, 0.605–0.777). In logistic regression models, criteria‐derived posttest odds of pPD were a significant predictor of conversion at follow‐up. 

In individuals age 65 or more participating in the Hellenic Longitudinal Investigation of Aging and Diet, a total of 16 of 21 markers of pPD were established . The probability of pPD was estimated for 961 individuals without PD or dementia with Lewy bodies who were followed‐up for an average of 3 years. These analyses were repeated using the original criteria.

This reflects suboptimal sensitivity for identification of pPD in community‐residing people. There were no specialized assessments with high likelihood ratios, which could explain why higher sensitivity was not seen. The authors of the study suggest such assessments be included in future validation attempts.