Mathias Susan, Crosby Ross D, Bayliss Martha S, L'Italien Gilbert, Sapra Sandhya
Health Outcomes Solutions, Winter Park, FL, USA,
Qual Life Res. 2014 Jun;23(5):1489-96. doi: 10.1007/s11136-013-0609-0. Epub 2013 Dec 31.
Chronic Hepatitis C (CHC) Virus infection is a serious health issue in the US. Standard treatment involves peginterferon alpha and ribavirin, often associated with adverse side effects including flu-like symptoms. These adverse effects are common reasons for the discontinuation of treatment and therefore represent a major obstacle in the effective treatment of CHC.
The Hepatitis Physical Symptom Severity Diary, a newly developed patient-reported outcome measure for assessing physical symptoms in CHC patients, was recently developed. It contains four questions addressing flu-like symptoms [the Flu-Like Symptom Index (FLSI)]. Measurement properties of the FLSI in CHC patients were assessed using data from two randomized clinical trials.
Exploratory factor analysis using data from baseline and the last visit while on treatment supported a single-factor solution for the FLSI. Internal reliability and test-retest reliability are acceptable (Cronbach's alpha range 0.73-0.81; intraclass correlation coefficient range 0.85-0.97), and correspondence to several similar constructs was acceptable. The FLSI score was higher among those with investigator-reported flu-like symptoms (mean = 4.1) versus those without (1.4), although not statistically significant (p = 0.12). Responsiveness of the FLSI was moderate, as measured by standardized effect sizes and response means, and the minimum important difference (MID) was estimated at 2.5-3.0 points.
While additional research should be conducted to evaluate validity with more closely related constructs and to utilize anchor-based methods for estimating the MID, data suggest that the FLSI has acceptable measurement properties and can be an effective tool in assessing flu-like symptoms in CHC patients.
慢性丙型肝炎（CHC）病毒感染在美国是一个严重的健康问题。标准治疗包括聚乙二醇化干扰素α和利巴韦林，常伴有包括流感样症状在内的不良反应。这些不良反应是治疗中断的常见原因，因此是CHC有效治疗的主要障碍。
最近开发了丙型肝炎身体症状严重程度日记，这是一种新开发的患者报告结局指标，用于评估CHC患者的身体症状。它包含四个针对流感样症状的问题[流感样症状指数（FLSI）]。使用来自两项随机临床试验的数据评估了CHC患者中FLSI的测量特性。
使用治疗期间基线和末次访视的数据进行探索性因素分析，支持FLSI的单因素解决方案。内部信度和重测信度可以接受（Cronbach's α范围为0.73 - 0.81；组内相关系数范围为0.85 - 0.97），与几个类似结构的对应性也可以接受。有研究者报告的流感样症状的患者的FLSI评分（平均 = 4.1）高于无此症状的患者（1.4），尽管差异无统计学意义（p = 0.12）。通过标准化效应量和反应均值测量，FLSI的反应性为中等，最小重要差异（MID）估计为2.5 - 3.0分。
虽然应进行更多研究以评估与更密切相关结构的效度，并使用基于锚定的方法估计MID，但数据表明FLSI具有可接受的测量特性，并且可以成为评估CHC患者流感样症状的有效工具。
