University of Idaho, 875 Perimeter Drive MS2401, Moscow, ID, 83844, USA.
California State University Dominguez Hills, 1000 E. Victoria Street, Carson, California, 90747, USA.
Health Qual Life Outcomes. 2020 Feb 18;18(1):32. doi: 10.1186/s12955-020-01292-5.
Quality of life (QoL) is important to assess in patient care. Researchers have previously claimed validity of the Quality of Life Scale (QOLS) across multiple samples of individuals, but close inspection of results suggest further psychometric investigation of the instrument is warranted. Therefore, the purposes of this study were to: 1) evaluate the proposed five-factor, 15-item and three-factor, 16-item QOLS; 2) if the factor structure could not be confirmed, re-assess the QOLS using exploratory factor analysis (EFA) and covariance modeling to identify a parsimonious refinement of the QOLS structure for future investigation.
Participants varying in age, physical activity level, and identified medical condition(s) were recruited from clinical sites and ResearchMatch. Confirmatory factor analyses (CFA) were performed on the full sample (n = 1036) based on proposed 15- and 16-item QOLS versions. Subsequent EFA and covariance modeling was performed on a random subset of the data (n = 518) to identify a more parsimonious version of the QOLS. The psychometric properties of the newly proposed model were confirmed in the remaining half of participants (n = 518). Further examination of the scale psychometric properties was completed using invariance testing procedures across sex and health status sub-categories.
Neither the 15- nor 16-item QOLS CFA met model fit recommendations. Subsequent EFA and covariance modeling analyses revealed a one-factor, five-item scale that satisfied contemporary statistical and model fit standards. Follow-up CFA confirmed the revised model structure; however, invariance testing requirements across sex and injury status subgroups were not met.
Neither the 15- nor 16-item QOLS exhibited psychometric attributes that support construct validity. Our analyses indicate a new, short-form model, might offer a more appropriate and parsimonious scale from some of the original QOLS items; however, invariance testing across sex and injury status suggested the psychometric properties still vary between sub-groups. Given the scale design concerns and the results of this study, developing a new instrument, or identifying a different, better validated instrument to assess QoL in research and practice is recommended.
生活质量（QoL）对于评估患者护理非常重要。研究人员此前曾声称，生活质量量表（QOLS）在多个个体样本中具有有效性，但对结果的仔细检查表明，该工具需要进一步进行心理测量学研究。因此，本研究的目的是：1）评估提出的五因素、15 项和三因素、16 项 QOLS；2）如果无法确认因素结构，则使用探索性因素分析（EFA）和协方差建模重新评估 QOLS，以确定未来研究中 QOLS 结构的简化。
从临床地点和 ResearchMatch 招募了年龄、身体活动水平和确定的医疗状况不同的参与者。根据提出的 15 项和 16 项 QOLS 版本，对全部样本（n=1036）进行验证性因素分析（CFA）。随后在数据的随机子集（n=518）上进行 EFA 和协方差建模，以确定 QOLS 的更简化版本。在剩余的一半参与者（n=518）中确认了新提出模型的心理测量特性。通过在性别和健康状况亚类中进行不变性测试程序，进一步检查了量表的心理测量特性。
15 项和 16 项 QOLS 的 CFA 均不符合模型拟合建议。随后的 EFA 和协方差建模分析显示，一个具有五个项目的单因素量表满足了当代统计和模型拟合标准。后续的 CFA 证实了修订后的模型结构；然而，在性别和损伤状态亚组之间没有满足不变性测试要求。
15 项和 16 项 QOLS 均未表现出支持构念有效性的心理测量属性。我们的分析表明，一个新的简短形式模型可能会从原始 QOLS 项目中提供一个更合适和简化的量表；然而，在性别和损伤状态之间的不变性测试表明，心理测量特性在子组之间仍然存在差异。鉴于量表设计问题和本研究的结果，建议开发新的工具或确定另一种经过验证的更好的工具来评估研究和实践中的生活质量。
