以項目反應理論協助發展，簡版慢性疾病生活品質量表

Developing an abbreviated WHOQOL-BREF for patients with major chronic diseases with the assistance of Item Response Theory (IRT)

目標：為減輕慢性病患者在門診、急診時，以及後續定期追蹤時的評估時間及負擔，本文針對六種重大慢性病患者，除考量傳統計量方法，並藉由項目反應理論（IRT）的輔助來開發簡版慢性病患WHOQOL-BREF問卷，以協助評估該些族群健康相關生活品質。方法：本文的發展目標為將有四個範疇26個題目的WHOQOL-BREF問卷，縮減為每個範疇有三個題目的結構。研究數據來自國民健康署與國家衛生研究院的國民健康訪問調查（National Health Interview Survey, NHIS）。在NHIS中，13,008名年齡在20歲至65歲之間的參與者完整填答了WHOQOL-BREF問卷。我們使用了其中1,263名患有經過醫生診斷的主要慢性疾病的個案（594名女性）和7,657名健康人（3,644名女性）來發展此簡版慢性病問卷。在問卷發展階段，我們使用了四個標準：校正後題目與總分相關係數（corrected item-total correlation）、預測各整體範疇的反向迴歸模型（backward regression model）、內外適配度均方誤差指標(outfit and infit mean squares）、以及項目訊息量(item information)。在驗證階段，量表信度以受測者信度評估，並估計同時效度和區別效度。結果：研究結果顯示本研究所開發的量表具有良好的受測者信度並與相關聯的量表存在可接受的同時效度。此外，本量表在驗證上能區分健康個體和慢性病患者在每個領域的得分。結論：本文所開發的WHOQOL-BREF慢性疾病版本是可靠且有效的。

Objectives: To lower the burden and shorten the evaluation time of patients with chronic diseases before outpatient clinic appointments, in the emergency room, and during regular follow-ups, a short version of the WHOQOL-BREF assessment was developed for patients with major chronic diseases to assess health-related quality of life with classical test theory methods and item response theory (IRT) analysis. Methods: The proposed assessment has four domains, with three items in each domain. This version was developed based on data from the National Health Interview Survey (NHIS) in Taiwan. In the NHIS, 13,008 Taiwanese participants between the ages of 20 and 65 completed the WHOQOL-BREF assessment. Among the participants, 1,263 individuals (594 females) with major chronic diseases and 7,657 healthy individuals (3,644 females) were included in the development and validation processes. In the development stage, four criteria were used: the corrected item-total correlation, backward regression models of the general domains, the outfit and infit mean squares, and the item information. In the validation stage, the reliability was measured according to the person reliability, and the validity was estimated based on the concurrent and known-groups validities. Results: The findings indicated good person reliability and acceptable concurrent validity with related scales. Additionally, the new assessment distinguished scores between healthy individuals and those with chronic diseases in each domain. Conclusions: The proposed short version of the WHOQOL-BREF was reliable and valid. Therefore, this new form is recommended for use in clinical settings.