失智症前期患者專用之電腦化日常認知功能測驗(CECFA)的心理計量特性驗證

Abstract

背景及目的：全球正積極發展預防失智症的介入策略，尤其針對失智症高危險群-失智症前期 (pre-dementia)患者，包含輕度認知障礙(mild cognitive impairment, MCI)及主觀認知衰退(subjective cognitive decline, SCD)患者。此類患者的認知功能改變可能已些微影響其日常生活功能，但目前少有可敏感測試認知相關日常生活功能的評估工具，因此研究團隊發展本土化工具-電腦化日常認知功能測驗(Computerized Everyday Cognitive Function Assessment, CECFA)，以出門購物日常活動為主，測試注意力、聽覺理解、執行功能、工作記憶、回溯及前瞻記憶、面對記憶干擾等認知面向之表現等，透過電腦施測，可紀錄其正確率及完成時間。本研究目的為探討CECFA應用於老人與失智症前期患者之可行性，並驗證其再測信度、內部一致性、聚合效度及區辨效度，並探討影響CECFA測驗結果之相關變項，以作為失智症前期之篩檢工具及臨床介入療效之功能指標。 方法：本研究以橫斷研究法，採方便性取樣。預計招募健康成人、SCD患者及MCI患者進行測試。本研究將使用操作回饋問卷進行此工具之可行性分析，以效應值 (effect size) Cohen’s d 檢驗學習效應，以各組於正確性獲得滿分與零分之人數比例檢驗是否有天花板或地板效應。再測信度為間隔1個月左右再次施測，而內部一致性以Cronbach's α係數檢驗。另使用變異數分析(Analysis of variance, ANOVA) 及費雪LSD事後比較（Fisher’s LSD text, post-hoc comparisons） 驗證其區辨效度，檢驗不同診斷族群（健康老人、SCD、MCI）及不同年齡層受試者之測驗結果是否具顯著差異。聚合效度使用皮爾森積差相關分析(Pearson r correlations) 檢驗CECFA之測驗結果與蒙特利爾認知評估MoCA (The Montreal Cognitive Assessment, MoCA)及主觀認知衰退問卷SCD-Q (Subjective Cognitive Decline Questionnaire, SCD-Q)分數間的關聯性。並使用多變項線性迴歸(multiple linear regression)，瞭解可能影響受試者CECFA測驗表現的相關變項。 結果：共納入119人（健康成人79人，SCD患者24人，MCI 患者16人），結果顯示：1)大多受試者認為評估輕鬆愉快，指令清楚易理解、平板操作容易且兩次測驗的難度相近。CECFA對於健康組年輕人（40.54%）及中高齡長者（16.67%）具天花板效應，其餘組別則無(0%)，且各組皆無地板效應(0%)。以兩次測驗正確率及完成時間計算出之 d 值分別為 0.49、0.48，顯示CECFA具低度學習效應。2) 信度方面，其內部一致性佳（Cronbach's alpha＝0.768）。另間隔一個月之兩次測驗正確率總分及總完成時間之ICC值分別為 0.681及0.843，顯示再測信度良好。3) 不同年齡組別間在正確率(p < 0.001，η2p =0.36 )及總完成時間(p < 0.001，η2p =0.38 )達顯著差異；而不同診斷間僅在正確率達顯著差異(p < 0.001，η2p =0.23 )。4) CECFA的正確率與SCD-Q與MoCA分數之相關性達顯著（r= -0.46，p<0.001；r=0.67，p<0.001）；其總完成時間與SCD-Q與MoCA分數之相關性達顯著（r=0.18，p=0.048；r= -0.54，p<0.001），聚合效度佳。5) 回歸分析顯示性別、年齡、教育程度、認知功能、焦慮情緒及診斷類別皆會影響CECFA之測驗結果。 結論： CECFA的可行性及信效度尚可。CECFA的正確率可區辨不同年齡族群，以及健康中高齡長者與MCI患者，但完成時間受年齡影響較大。性別、年齡、教育程度會影響CECFA之測驗結果，可作為計分及建立常模時之參考。

Background and purposes: Dementia prevention is one global public health priority, especially for the high-risk populations – people who are pre-dementia, including patients with mild cognitive impairment (MCI) and subjective cognitive decline (SCD). The cognitive function changes of such patients may have slightly affected their daily living functions; there are currently few assessment tools that can sensitively test cognitive-related daily living functions. Therefore, the research team designed a local tool for evaluating cognition-related daily living functions---the Computerized Everyday Cognitive Function Assessment (CECFA). CECFA assesses attention, auditory comprehension, executive function, working memory, retrospective and prospective memory, and memory with disturbance. The accuracy and completion time can be recorded through the computer test. The purpose of this study is to investigate the feasibility of applying CECFA to healthy populations and pre-dementia patients and to verify its test-retest reliability, internal consistency, convergent validity, and discriminant validity. In addition, we explored the variables that affect the results of CECFA. Methods: This study was conducted with a cross-sectional study method and convenience sampling. Healthy adults, SCD patients, and MCI patients were recruited for testing. This research would use the feedback questionnaire to conduct a feasibility analysis of CECFA, using Cohen's d to test the learning effect and explore whether there is a ceiling or floor effect by the proportion of the number of people who get full and zero points in each group. Test-retest reliability would be tested with an interval of more than one month, and Cronbach's Alpha coefficient measured the internal consistency. In addition, analysis of variance (ANOVA) and Fisher's LSD post-hoc comparison would be used to verify the discriminant validity of CECFA and test whether the results of different diagnosis groups and age groups are significantly different. Pearson r correlations were used to test the convergent validity of CECFA with the MoCA (The Montreal Cognitive Assessment, MoCA) and the SCD-Q (Subjective Cognitive Decline Questionnaire, SCD-Q). Multiple linear regression was used to analyze the variables that might affect the results of CECFA. Results: There are total of 119 subjects (79 healthy adults, 24 SCD patients, and 16 MCI patients); the results of the study showed: 1) Most subjects thought the assessment was easy and pleasant, the instructions were clear and easy to understand, the tablet computer operation was easy, and two times of the test were similar in difficulty. There was a ceiling effect on young people (40.54%) and the elderly (16.67%) in the healthy group, while other groups were not (0%), and there was no floor effect (0%) in each group. The d value calculated by the accuracy and the total completion time were 0.49 and 0.48, which was a low learning effect. 2) Regarding reliability, the internal consistency of CECFA was good (Cronbach's alpha=0.768). The ICC values of the accuracy and the total completion time of the two tests at a one-month interval were 0.681 and 0.843, indicating good test-retest reliability. 3) The accuracy (p < 0.001, η2p = 0.36 ) and total completion time (p < 0.001, η2p = 0.38 ) were significantly different among age groups, and only the accuracy was significantly different among three diagnoses (p < 0.001, η2p = 0.23). 4) The convergent validity of CECFA is good, the correlation between accuracy and SCD-Q score (r= -0.46, p<0.001) and MoCA score(r=0.67, p<0.001) were significant, and the correlation between total completion time and SCD-Q score (r= 0.18, p=0.048) and MoCA score (r= -0.54, p<0.001) were also significant. 5) Regression analysis showed that gender, age, education level, cognitive function, anxiety, and diagnostic category are the influencing variables of the results of CECFA. Conclusion: This study shows that the feasibility, reliability, and validity of CECFA are acceptable. The discriminant validity of CECFA accuracy is significant, which can effectively distinguish different age groups and between healthy elderly and MCI patients, and the total completion time is greatly affected by age. Gender, age, and education level will affect the test results of CECFA, which can be used as a reference for scoring and establishing norms.