Turkish Validation of the Parkinson Disease Cognitive Functional Rating Scale

The Parkinson's Disease-Cognitive Functional Rating Scale (PD-CFRS) is one of the Parkinson's disease-specific instruments developed to assess a broad range of functional impairments resulting from cognitive deficits in individuals with Parkinson's disease (PD). The PD-CFRS is specifically designed to evaluate cognitive dysfunction while minimizing the confounding effects of motor symptoms.

The scale consists of 12 items that assess whether the patient experiences difficulties in performing activities such as managing money and household finances, arranging vacations or meetings, handling personal correspondence, checking medication schedules, organizing daily routines, using electrical appliances, understanding public transportation, dealing with unforeseen situations, expressing intentions, comprehending written information, and using a mobile phone.

Each item is rated on a 3-point scale ranging from 0 to 2. If the participant has never performed the activity in question, a score of 8 is assigned. At the end of the assessment, the average score for items rated between 0 and 2 is calculated and rounded to the nearest whole number. This value replaces all items initially scored as 8. Once all substituted scores are assigned, the total score is obtained by summing all item scores. The administration time for the scale is approximately 5 minutes.

Primary outcomes

• Validity of the Turkish Version of the Parkinson's Disease Cognitive Functional Rating Scale [Baseline]: 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.

Secondary outcomes

• Reliability of the Turkish Version of the Parkinson's Disease Cognitive Functional Rating Scale [Repeated measurements will be conducted at a 2 week interval.]: 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).
• Mini Mental State Examination Score [Baseline]: 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 Score [Baseline]: 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.
• MDS-Unified Parkinson's Disease Rating Scale Part 3: Motor Examination Score [Baseline]: 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.
• Hoehn and Yahr Scale [Baseline]: 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.
• Hospital Anxiety and Depression Scale Scores [Baseline]: 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.

Sex: All, ages: 40 Years to any

Inclusion Criteria:

* Clinically diagnosed with idiopathic Parkinson's disease by a neurologist.
* Evaluated between Stage 1-3 according to the Hoehn and Yahr Staging Scale.
* Aged 40 years or older.
* Agreed to participate in the study after being given sufficient information.

Exclusion Criteria:

* Patients with a Montreal Cognitive Assessment score of 20 and below.
* Patients with cardiovascular, vestibular, musculoskeletal or additional neurological disease.

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• Emre Adıgüzel, Prof., MD., Study director, Ankara City Hospital Bilkent
• Arzu Güçlü Gündüz, Prof., PT., Principal investigator, Gazi University