Minimal Clinically Important Difference on Parkinson's Disease Sleep Scale 2nd Version.

Area of Science:

• Neurology
• Sleep Medicine
• Clinical Outcome Measures

Background:

• Parkinson's disease (PD) significantly impacts sleep quality.
• The Parkinson's Disease Sleep Scale 2nd version (PDSS-2) is a key tool for assessing sleep disturbances in PD patients.
• Establishing minimal clinically important difference (MCID) for the PDSS-2 is crucial for interpreting patient outcomes.

Purpose of the Study:

• To determine the minimal clinically important difference (MCID) for the total score and individual dimensions of the PDSS-2.
• To provide evidence-based thresholds for meaningful changes in sleep quality for PD patients.

Main Methods:

• A cohort of 413 Parkinson's disease patients was studied.
• Validated scales including MDS-UPDRS, Hoehn-Yahr Scale, Mattis Dementia Rating Scale, and PDSS-2 were administered at baseline.
• PDSS-2 reevaluation occurred after nine months, alongside the Patient-Reported Global Impression Improvement Scale.
• Anchor-based (within-patient change, ROC analysis) and distribution-based (effect size) methods were employed to calculate MCID.

Main Results:

• Clinically important improvement on the PDSS-2 was defined as a change greater than -3.44 points.
• Clinically important worsening was defined as a change greater than 2.07 points.
• These thresholds corresponded to an effect size of 0.21 for improvement and -0.21 for worsening.

Conclusions:

• Minimal clinically important differences represent the smallest score changes perceived as meaningful by patients.
• The established thresholds of -3.44 for improvement and 2.07 for worsening should guide the interpretation of PDSS-2 scores in clinical studies.
• These findings enhance the clinical utility of the PDSS-2 for tracking treatment efficacy and disease progression in Parkinson's disease.