輕度認知障礙者的工具性日常生活活動表現及其困難：以質性及量性研究方法探討

Abstract

背景與目的：輕度認知障礙(mild cognitive impairment, MCI)的進階日常活動功能，包含工具性日常生活(instrumental activities of daily living, IADL)及休閒娛樂(本文將以IADL統稱之)出現各種困難。過去研究顯示MCI個案的IADL功能評估呈現不一致的結果，由於現有評估工具多未針對MCI設計，測驗方式與結果解讀仍有部分限制，且因個人的IADL參與項目差異性高，單純使用量性評量工具，無法全面了解MCI的IADL困難。而質性研究可深入探究個體的經驗、文化，詳實的觀察記錄個案的生活困難。故本研究目的為從不同面向瞭解MCI個案於IADL上的問題與主觀感受，並進一步釐清不同評量IADL方式所獲得資訊的意涵。 方法：本研究採立意取樣，招募9位失憶型MCI個案與9位主要照顧者，以三角驗證(triangulation)中的方法論，利用質性與量性之多元資料來源，探索個案在IADL的表現與困難。量性方法以問卷(中文版失智症功能障礙評估量表，DAD)及IADL實作測驗(操作型日常生活技巧評估-簡短版，UPSA-B)等蒐集個案IADL表現之資料；質性方法針對個案及照顧者進行深入訪談，錄音、並完成逐字稿，分析時依據直接內容分析的原則，以DAD的題項為基本編碼，以IADL執行狀況、情境與活動表現等作系統性的了解，並互相比對質量性資料來源的結果。 結果：分析比較DAD，UPSA-B評估結果與質性資料所得資訊，DAD的結果顯示，部分個案已無法獨立完成財務、準備飯餐、通電話、外出、搭車、服藥、家務、休閒等IADL項目。但照顧者對於個案的熟悉度會影響評分結果的可信度；部分個案因能力不足而不需從事特定活動時，評分為「沒有困難」，將無法呈現個案實際在IADL的狀況。而在表現型測驗中，即便個案在DAD未有明顯困難，但明顯可發現其在UPSA-B執行的困難，如不了解指令或題意，記憶力不佳而影響執行任務的正確性，花費較長時間摸索，採無效率的方法嘗試錯誤等，個案雖可能最終達成任務，但其中的困難與調適方式，較不是問卷型測驗所能得知。而在質性資料中，深入了解了每位個案的生活、背景、喜好、活動的選擇，補充上述二種評量所未發現的活動困難，且更有脈絡地得知個案認知功能狀態的改變（如注意力及記憶不佳）如何影響IADL的表現（如找不到路回家），及其情緒反應（如害怕一人出門）與因應的方式（如不出門或要家人陪同才出門）。但也從中發現了各個評估方式所獲得個案IADL表現情況的面向不同，故結果也不完全一致。 結論：本研究藉由質性與量性等三種不同的評估方式，探討MCI個案在IADL表現的不同面向，可以互相補充資料的完整性，使對於其生活功能上的困難、情緒反應與調適的方式等有較全面的瞭解。但實務評估上，難以全面執行訪談及各種評量，未來可依據本研究中提出MCI的IADL表現特性，發展具信效度，能較精準篩選個案，及靈敏反應其日常功能變化的評量工具。

Background and aim: Recent research suggests that people with mild cognitive impairment (MCI) encounter various difficulties in advanced daily function, including instrumental activities of daily living (IADL) and leisure (included in IADL in this study). IADL assessments were seldom developed specifically for MCI. Its application and clinical interpretations of the results can be problematic. Results from various IADL assessments for MCI often showed inconsistent results. In addition, IADL participation shows great individual variations, the fixed items in quantitative assessments often fail to yield a realistic representation of these variations. Qualitative research method can explore the individuals’ experiences from their perspectives and is not limited by the fixed items of the quantitative assessments, and therefore, help to achieve a more thorough understanding of their IADL difficulties. This study used a mixed method approach. The goals are to investigate various perspectives of IADL performance of persons with MCI and clarify the underlying properties measured by different IADL evaluation. Methods: Nine pairs of persons with amnestic MCI and their caregivers were recruited by purposive sampling. Methodological triangulation by using both qualitative and quantitative methods was conducted to increase the quality of data. The quantitative method evaluated participants’ function with a self-reported questionnaire (The Disability Assessment for Dementia, DAD) and a performance-based measure (UCSD Performance-Based Skills Assessment -Brief, UPSA-B). Each participant completed individual in-depth interviews, which were recorded and transcribed verbatim. Qualitative content analysis of the interview transcripts and evaluation results were used to systematically investigate the IADL performance. DAD items were used as the initial coding system for the analysis. Qualitative and quantitative results of the assessments were juxtaposed and triangulated with each other. Result: The results of DAD evaluation showed that some persons with MCI could not perform IADL independently, such as finance, meal preparation, telephoning, outing, transportation, medication, and leisure. However, these tasks were often scored as NA (not applicable) by the scoring system indicated in the manuals as the client did not need to execute this task , and NAs would be excluded from the caculation of total score.. Some stated that the persons with MCI did not participate in certain IADL because their inability to independently complete the tasks. However, caregiver’s influences on how certain IADL was done affected the reliability. For certain tasks, the persons with MCI demonstrated significant difficulties during UPSA-B, even with a perfect score on DAD. The participants with MCI were observed to not understand the instructions immediately, need to take longer time to finish a task, to solve the problem by trial and error, et al. Qualitative interviews allowed the caregivers and the persons with MCI to systematically reflect upon their IADL experiences with declining cognitive ability, its influence on their IADL performance, emotional responses, and coping strategies. The juxtapositions of results from questionnaires, performance-based measures, and interviews showed an inconsistent picture of a person’s IADL state due to the different perspectives of IADL performance obtained from various data resources. Conclusion: The results from different methods could supplement each other and provide a more comprehensive understanding of the cognitive impairment, its consequences in everyday life, and emotional and adaptive strategies of people with MCI. But in clinical practice, it is impractical to conduct all above methods for ADL assessment. We need an evaluation tool that is tailored to the unique features of IADL decline in MCI population, with good psychometric properties, and being sensitive to detect the functional change.