Broström Anders, Pakpour A H, Nilsen P, Fridlund B, Ulander M
Department of Nursing, School of Health and Welfare, Jönköping University, Jönköping, Sweden.
Department of Clinical Neurophysiology, Linköping University Hospital, S-581 85, Linköping, Sweden.
Sleep Breath. 2019 Sep;23(3):761-768. doi: 10.1007/s11325-018-1762-z. Epub 2018 Dec 6.
Continuous positive airway treatment (CPAP) is the recommended treatment for patients with obstructive sleep apnea (OSA). Outcome measures often focus on clinical and/or self-rated variables related to the medical condition. However, a brief validated instrument focusing on the whole life situation (i.e., ethos) suitable for clinical practice is missing. The aim of this study was to investigate factorial structure, categorical functioning of the response scale, and differential item functioning across sub-populations of the Ethos Brief Index (EBI) among patients with obstructive sleep apnea (OSA) before and after initiation of continuous positive airway pressure (CPAP).
A prospective design, including 193 patients with OSA (68% men, 59.66 years, SD 11.51) from two CPAP clinics, was used. Clinical assessment and overnight respiratory polygraphy were used to diagnose patients. Questionnaires administered before and after 6 months of CPAP treatment included EBI, Epworth Sleepiness Scale (ESS), Hospital Anxiety and Depression Scale, and global perceived health (initial item in SF-36). The validity and reliability of the EBI were investigated using Rasch and confirmatory factor analysis models. Measurement invariance, unidimensionality, and differential item functioning across gender groups, Apnea-Hypopnea Index, and ESS groups were assessed.
The reliability of the EBI was confirmed using composite reliability and Cronbach's alpha. The results supported unidimensionality of the EBI in confirmatory factor analysis and the Rasch model. No differential item functioning was found. A latent profile analysis yielded two profiles of patients with low (n = 42) and high (n = 151) ethos. Patients in the low ethos group were younger and had higher depression scores, lower perceived health, and higher body mass index.
The EBI is a valid tool with robust psychometric properties suitable for use among patients with OSA before and after treatment with CPAP is initiated. Future studies should focus on its predictive validity.
持续气道正压通气治疗（CPAP）是阻塞性睡眠呼吸暂停（OSA）患者的推荐治疗方法。结果测量通常侧重于与该疾病相关的临床和/或自评变量。然而，目前缺少一种适用于临床实践的、聚焦于整体生活状况（即精神风貌）的简短且经过验证的工具。本研究的目的是调查阻塞性睡眠呼吸暂停（OSA）患者在开始持续气道正压通气（CPAP）治疗前后，精神风貌简要指数（EBI）的因子结构、反应量表的分类功能以及不同亚组间的项目差异功能。
采用前瞻性设计，纳入了来自两家CPAP诊所的193例OSA患者（68%为男性，平均年龄59.66岁，标准差11.51）。通过临床评估和夜间呼吸多导睡眠图对患者进行诊断。在CPAP治疗6个月前后发放的问卷包括EBI、爱泼华嗜睡量表（ESS）、医院焦虑抑郁量表以及总体健康感知（SF - 36中的初始项目）。使用拉施模型和验证性因子分析模型对EBI的有效性和可靠性进行研究。评估了不同性别组、呼吸暂停低通气指数组和ESS组之间的测量不变性、单维度性和项目差异功能。
通过组合信度和克朗巴哈系数证实了EBI的信度。结果支持EBI在验证性因子分析和拉施模型中的单维度性。未发现项目差异功能。潜在类别分析得出了低精神风貌（n = 42）和高精神风貌（n = 151）两类患者。低精神风貌组的患者更年轻，抑郁得分更高，健康感知更低，体重指数更高。
EBI是一种有效的工具，具有稳健的心理测量特性，适用于OSA患者在开始CPAP治疗前后。未来的研究应关注其预测效度。
