The Hopkins Symptom Checklist (SCL-90-R): A Patient-Reported Outcome Measure in Parkinson's Disease

Objective: This is the first study applying Clinimetric Patient-Reported Outcome Measures (CLIPROM) criteria to evaluate the construct validity, sensitivity, and clinical utility of the SCL-90-R in patients with Parkinson's disease (PD). Methods: A Rasch analysis was conducted using a sample of 488 PD outpatients. Results: Testing for dimensionality revealed that less than 5% of t-tests were significant, indicating that the SCL-90-R subscales entailed the property of construct validity. As to the total score, a Person Separation Reliability Index of .96 was found. Conclusions: The SCL-90-R total score is a sensitive screening measure that can be used not only to differentiate healthy stress reactions from symptoms of psychological distress but also to detect PD patients with an increased risk for psychiatric complications. As to the subscales, the brief versions that did not include misfitting items should be used to assess the severity of specific symptoms of psychological distress affecting PD patients.