Balparda Kepa, Herrera-Chalarca Tatiana, Cano-Bustamante Melissa
Department of Cornea and Refractive Surgery, Black Mammoth Surgical, Carrera 43 # 29 - 35, Office 712, Medellín, Colombia.
Department of Clinical Research, Black Mammoth Surgical, Medellín, Colombia.
Eye Vis (Lond). 2022 May 8;9(1):17. doi: 10.1186/s40662-022-00288-0.
Measuring quality of life is of importance in keratoconus. So far, the Keratoconus End-Points Assessment Questionnaire (KEPAQ) is the only keratoconus-specific scale to measure emotional well-being along with functional compromise in this population. Nevertheless, there is still a lack of clarity and standardization as to how KEPAQ scores should be computed and reported. There are also no guidelines for interpretation of classification of quality of life when using this instrument. The purpose of this study is to provide a specific framework on how to grade and classify keratoconus by using the KEPAQ and propose an extension of current classification to encompass subjective compromise.
A group of patients with a confirmed diagnosis of keratoconus underwent application of the KEPAQ. First, a Rasch modeling was performed to evaluate the psychometric characteristics of both sub-scales of the instrument. Then, a linear transformation was performed to turn data into a more relatable scale ranging from 0 to 100. Finally, by using Tukey's Hinges, scores of the KEPAQ were divided in a 1-to-4 scale, allowing for an easy E&F classification system.
A total of 386 applications of the KEPAQ were included. Analysis provided evidence of the KEPAQ being unidimensional, well-fitted to the Rasch Model, and provided adequate interval-level scores. Linear transformation resulted in a user-friendly final score ranging from 0 to 100, where a higher score translates to having a better quality of life. Two methods of easily computing final score, one by hand and the other one by an Excel file, were constructed. An E&F 1-to-4 classification was proposed, which may work well with the current ABCD classification of keratoconus.
The KEPAQ is a psychometrically robust scale, which confidently measures both emotional-related and functional-related quality of life in patients with keratoconus. It can be easily computed, and the results are interpretable and classified in a manner similar to that used in the ABCD keratoconus classification, by adding letters 'E' for emotional and 'F' for functional compromise.
测量圆锥角膜患者的生活质量具有重要意义。到目前为止，圆锥角膜终点评估问卷（KEPAQ）是唯一一种用于测量该人群情绪健康以及功能损害的圆锥角膜特异性量表。然而，关于KEPAQ分数应如何计算和报告仍缺乏明确性和标准化。在使用该工具时，也没有生活质量分类的解释指南。本研究的目的是提供一个关于如何使用KEPAQ对圆锥角膜进行分级和分类的具体框架，并提出对当前分类的扩展，以涵盖主观损害。
一组确诊为圆锥角膜的患者接受了KEPAQ评估。首先，进行拉施模型分析以评估该量表两个子量表的心理测量特征。然后，进行线性变换，将数据转换为范围从0到100的更具可比性的量表。最后，使用Tukey's Hinges方法，将KEPAQ分数分为1至4级，从而形成一个简单的E&F分类系统。
共纳入386份KEPAQ评估。分析表明KEPAQ具有单维度性，很好地拟合了拉施模型，并提供了足够的区间水平分数。线性变换产生了一个用户友好的最终分数，范围从0到100，分数越高表明生活质量越好。构建了两种轻松计算最终分数的方法，一种是手动计算，另一种是通过Excel文件计算。提出了E&F 1至4级分类，这可能与当前的圆锥角膜ABCD分类配合良好。
KEPAQ是一种心理测量稳健的量表，能够可靠地测量圆锥角膜患者与情绪相关和与功能相关的生活质量。它易于计算，结果可解释，并能以类似于圆锥角膜ABCD分类的方式进行分类，通过添加代表情绪的字母“E”和代表功能损害的字母“F”。
