Global Journal of Medical Research, A: Neurology & Nervous System, Volume 23 Issue 3

students. Additional inclusion criteria; All participants were aged over 18 years, able to speak and read Greek fluently, and provide themself or/and their caregivers with full detailed information and consent forms. Exclusion criteria were any type of comorbidities such as cardiovascular disease and psychiatric disorder; individuals with motor deficits in handwriting; other reasons such as medication or/and alcohol use that may affect participants’ mental function and/or mental health; participants with a covid-19 diagnosis were excluded. Table 1: Sample Frequencies Disease Type Frequency Percentage Mild Cognitive Impairment 44 15.5% Dementia 57 20.1% Multiple Sclerosis 68 24.0% Systemic Lupus Erythematosus 71 25.1% Health Control 43 15.2% IV. R esults a) Internal consistency The reliability of CLOX: an Executive Clock-Drawing Task, has been investigated as a scale of measurement in the Greek population. This examination focused on individuals with specific diseases, including MCI, dementia spectrum disorders, MS, SLE, and health control. A total of 283 participants successfully completed the scale. The evaluation of the internal consistency of the CLOX task was conducted based on the reported Cronbach's alpha values. The initial task, comprising 15 items, exhibited satisfactory internal consistency, as indicated by a Cronbach's alpha coefficient of .798. The second task, which also comprised 15 items, demonstrated satisfactory internal consistency, as evidenced by a Cronbach's alpha coefficient of .785. When examining the comprehensive scale comprising all 30 items, the internal consistency was found to be highly satisfactory, as indicated by a Cronbach's alpha coefficient of .874. The results of this study indicate that the CLOX: An Executive Clock- Drawing Task demonstrates a high level of reliability as a tool for evaluating executive functioning and cognitive impairment in the Greek population. This is particularly applicable to individuals with MCI, dementia, MS, and SLE. The high level of internal consistency, ranging from good to very good, suggests that the items within the CLOX task are effectively measuring a cohesive construct in a reliable manner. Therefore, the study proposes that the CLOX: An Executive Clock-Drawing Task is a dependable tool for evaluating executive functioning and cognitive impairment in the Greek population, particularly in individuals diagnosed with MCI, dementia, MS, and SLE, based on the obtained results. The high level of internal consistency observed in the task suggests that the items comprising the CLOX task consistently assess the targeted construct of executive functioning and cognitive impairment. b) Construct Validity A Principal Component Analysis (PCA) was conducted on the CLOX task 1 items. The interpretations of Kaiser-Meyer-Olkin Measure of Sampling Adequacy: .787 indicates that the sample used in the analysis is considered adequate for conducting PCA. Generally, a value above .6 is considered acceptable. Bartlett's Test of Sphericity ( χ 2105= 1097.418 (<.001) suggests that the correlation matrix is not an identity matrix, indicating that there is a sufficient correlation among the variables for PCA to be meaningful. Therefore, the significant p-value of less than 0.001 suggests that there is enough correlation among the variables in the CLOX task 1 items, indicating that PCA is meaningful and can be applied to extract underlying factors or dimensions from the data. For example, for CLOX1.1, the initial commonality is 1.000, indicating that the item explains 100% of its own variance. The extraction communality is .428, suggesting that this item shares some common variance with the other items in the analysis (please see Appendix 1). Total Variance Explained shows the first component explains 27.360% of the variance, the second component explains 12.006%, and so on. The cumulative percentage indicates how much total variance is explained by the successive components. For example, the first two components explain a cumulative percentage of 39.366%. Therefore, the PCA results suggest that there are several components (factors) that contribute to the variation in the CLOX task 1 items. The first few components explain a significant proportion of the variance, while the subsequent components contribute less. In the same spirit, the Kaiser-Meyer-Olkin Measure of Sampling Adequacy for CLOX task 2 is .733, 62 Year 2023 Global Journal of Medical Research Volume XXIII Issue III Version I ( DD ) A © 2023 Global Journals Reliability and Validity Evaluation of the ‘’CLOX: An Executive Clock Drawing Task’’ in a Greek Population with Neurological and Autoimmune Diseases