University of Plymouth, Plymouth, UK.
Plymouth Marjon University, Plymouth, UK.
Health Qual Life Outcomes. 2020 Oct 9;18(1):336. doi: 10.1186/s12955-020-01593-9.
The Severe Asthma Questionnaire (SAQ) is a health related quality of life (HRQoL) questionnaire validated for use in severe asthma. It is scored using the mean value of 16 items (SAQ score) in addition to a single item global rating of HRQoL (SAQ-global). The aim was to validate clinically relevant subscales using exploratory factor analysis (EFA).
The SAQ was completed, along with measures of asthma control and EQ5D-5L by patients attending six UK severe asthma centres. Clinical data were included in the analysis. EFA using principal axis factoring and oblimin rotation was used to achieve simple structure of data.
460 patients with severe asthma participated, 65% women, mean age 51 (16-83) years. A three factor solution achieved best fit and showed that the SAQ items formed three distinct but inter-correlated groups of items where items were grouped in a way that was consistent with item content. The three subscales were differentially associated with clinically relevant variables (lung function and mood). Males and females interpreted the question of night disturbance in different ways.
This paper provides a template for best practice in the use of EFA when validating HRQoL subscales. The SAQ can be scored as three subscales with content reflecting three different constructs people with severe asthma use when making judgements about their lives. The subscale 'My Life' assesses the impact of severe asthma on different life activities, 'My Mind' assesses the perceived emotional impact and 'My Body' the impact of extra-pulmonary symptoms and side effects.
严重哮喘问卷（SAQ）是一种经过验证可用于严重哮喘的健康相关生活质量（HRQoL）问卷。它使用 16 个项目的平均值进行评分（SAQ 评分），外加一个 HRQoL 的单项总体评分（SAQ-global）。目的是使用探索性因素分析（EFA）验证临床相关子量表。
在英国六家严重哮喘中心就诊的患者完成了 SAQ 以及哮喘控制和 EQ5D-5L 测量。临床数据包含在分析中。使用主成分因子分析和 Oblimin 旋转进行 EFA，以实现数据的简单结构。
460 名严重哮喘患者参与了研究，其中 65%为女性，平均年龄 51（16-83）岁。三因素解决方案达到了最佳拟合，表明 SAQ 项目形成了三个不同但相互关联的项目组，项目以与项目内容一致的方式分组。这三个子量表与临床相关变量（肺功能和情绪）有不同的关联。男性和女性对夜间干扰问题的解释方式不同。
本文提供了在验证 HRQoL 子量表时使用 EFA 的最佳实践模板。SAQ 可以评分三个子量表，其内容反映了严重哮喘患者在判断生活时使用的三个不同结构。子量表“我的生活”评估严重哮喘对不同生活活动的影响，“我的思维”评估感知的情绪影响，“我的身体”评估肺外症状和副作用的影响。
