The validity of single-item measures of health-related quality of life across groups differing in acute respiratory symptom severity.

ABSTRACT

PURPOSE: Practical considerations precluding health-related quality of life (HRQOL) monitoring in population and clinical research have spawned development of improved items for more brief surveys of frequently measured HRQOL outcomes. The aim of this study was to validate the use of the Quality of Life General (QGEN-8), a shorter 8-item alternative to the longer 36-item short form (SF)-36 Health Survey for measuring the same eight HRQOL domains across groups of adults with varying severity of acute respiratory symptoms, such as cough and sore throat. METHODS: National Opinion Research Center (NORC) representative probability (N = 1,648) and supplemental opt-in (N = 5,915) U.S. adult samples were surveyed cross-sectionally online in 2020. Parallel analyses compared QGEN-8 and SF-36 estimates of group means for each of eight matching profile domains and summary physical and mental scores across groups differing in severity of acute symptoms and chronic respiratory conditions using analysis of covariance (ANCOVAs) controlling for socio-demographics and presence of chronic respiratory conditions. RESULTS: In support of discriminant validity, ANCOVA estimates of QGEN-8 means with SF-36 estimates revealed the same patterns of declining HRQOL with the presence and increasing severity of symptoms and chronic condition severity. CONCLUSION: QGEN-8® shows satisfactory validity and warrants further testing in cross-sectional and longitudinal population and clinical survey research as a more practical method for estimating group differences in SF-36 profile and summary component HRQOL scores.

Upper respiratory tract infections (URTI) with symptoms such as cough and sore throat are highly prevalent and negatively impact on health-related quality of life (HRQOL). Existing instruments that comprehensively measure HRQOL are lengthy, potentially increasing respondent burden and restricting their use in clinical studies and research. The aim of this study was to evaluate whether eight newly constructed survey items, the QGEN-8®, measure the same HRQOL outcomes as the 36-item SF-36 Health Survey well enough to serve as a more practical alternative for purposes of detecting the physical and mental HRQOL effects on differing severity of acute URTI symptoms, specifically cough and sore throat. The results showed that the QGEN-8® was psychometrically sound and able to differentiate between different levels of URTI symptoms, even in cases where respondents had chronic respiratory conditions. This indicates that the briefer QGEN-8® with 75% shorter response time is able to provide HRQOL measurements comparable to those derived from lengthier instruments thereby lending itself more readily to use in clinical studies and research of URTI symptoms, such as cough and sore throat.