Turkish Validation of the Parkinson Disease Cognitive Functional Rating Scale

Parkinson's Disease Cognitive Functional Rating Scale assesses the functional impact of cognitive impairment in individuals with Parkinson's disease. The 12-item scale assesses cognitive impairment while minimizing motor effects. Items are scored 0-2. Unperformed tasks (score 8) are replaced by the average of scored items and summed. The total score ranges from 0 to 24. Higher scores indicate worse outcomes.

The validity of the Turkish version of the scale will be evaluated through convergent and discriminant construct analyses. Convergent validity will be assessed by examining partial Pearson correlations between Parkinson's Disease Cognitive Functional Rating Scale scores and Mini-Mental State Examination and Montreal Cognitive Assessment scores.

Discriminant validity will be analyzed using binary logistic regression with Mini-Mental State Examination and Montreal Cognitive Assessment scores and disease duration as independent variables.

The 12-item Parkinson's Disease Cognitive Functional Rating Scale assesses cognitive impairment while minimizing motor effects. Items are scored 0-2. Unperformed tasks (score 8) are replaced by the average of scored items and summed. The total score ranges from 0 to 24. Higher scores indicate worse outcomes.

Test-retest reliability will be assessed by repeating the PD-CFRS administration after a two-week interval by the same examiner. The scale evaluates participants' cognitive skills over the previous two weeks. Reliability will be calculated using the Intraclass Correlation Coefficient (ICC).

Assessment of general cognitive function, including attention, orientation, memory, verbal responses, following verbal and written commands, sentence writing, and copying complex figures. The Mini-Mental State Examination is scored from 0 to 30, with a cutoff score of 24. Higher scores reflect better cognitive function, while scores below 24 suggest cognitive impairment. The score obtained from the test will be recorded.

Montreal Cognitive Assessment, which provides a general cognitive screening in different cognitive functions such as attention, concentration, executive functions, memory, language, visual structuring skills, abstract thought, calculation and orientation, will be used in the general evaluation of cognition. MoCA is an effective scale especially in the evaluation of mild cognitive impairments in Parkinson's disease. The cut-off score range of Montreal Cognitive Assessment has been shown to be 18-26 points in individuals with Parkinson's disease who has mild cognitive impairment. The administration of Montreal Cognitive Assessment takes approximately 10 minutes. The highest total score that can be obtained from the test is 30. Accordingly, a score of 21 points and above is considered normal. The score obtained from the test will be recorded.

Movement Disorders Society Unified Parkinson's Disease Rating Scale consists of 4 parts, like the classic Unified Parkinson's Disease Rating Scale. The severity of the patients' motor symptoms will be assessed using the Motor Examination part, which is the 3rd part of the MDS-Unified Parkinson's Disease Rating Scale. MDS-Unified Parkinson's Disease Rating Scale Part 3 consists of 18 items. All items in the scale are scored between 0 (Normal) and 4 (Severe) points. The score obtained from the test will be recorded.

The Hoehn and Yahr scale is a widely used clinical rating system that classifies the progression of Parkinson's disease into stages 1 through 5, primarily based on motor function, balance, and independence. It ranges from unilateral, mild symptoms (Stage 1) to being wheelchair-bound or bedridden (Stage 5). Higher scores reflect worse outcome.

The Hospital Anxiety and Depression Scale is a 14-item, self-administered questionnaire used to identify anxiety and depression in clinical settings. It consists of two subscales, 7 items each for anxiety and depression, focusing on cognitive and emotional symptoms while excluding physical symptoms, scoring 0-21 per scale. Each item is scored 0-3, with maximum subscale scores of 21. Higher scores indicate greater severity.