Barbaranelli Claudio, Lee Christopher S, Vellone Ercole, Riegel Barbara
Professor, Department of Psychology, Sapienza University, Rome, Italy.
Res Nurs Health. 2014 Dec;37(6):524-37. doi: 10.1002/nur.21623. Epub 2014 Oct 16.
The Self-Care of Heart Failure Index (SCHFI) is used widely, but issues with reliability have been evident. Cronbach alpha coefficient is usually used to assess reliability, but this approach assumes a unidimensional scale. The purpose of this article is to address the dimensionality and internal consistency reliability of the SCHFI. This was a secondary analysis of data from 629 adults with heart failure enrolled in three separate studies conducted in the northeastern and northwestern United States. Following testing for scale dimensionality using confirmatory factor analysis, reliability was tested using coefficient alpha and alternative options. Confirmatory factor analysis demonstrated that: (a) the Self-Care Maintenance Scale has a multidimensional four-factor structure; (b) the Self-Care Management Scale has a two-factor structure, but the primary factors loaded on a common higher-order factor; and (c) the Self-Care Confidence Scale is unidimensional. Reliability estimates for the three scales, obtained with methods compatible with each scale's dimensionality, were adequate or high. The results of the analysis demonstrate that issues of dimensionality and reliability cannot be separated. Appropriate estimates of reliability that are consistent with the dimensionality of the scale must be used. In the case of the SCHFI, coefficient alpha should not be used to assess reliability of the self-care maintenance and the self-care management scales, due to their multidimensionality. When performing psychometric evaluations, we recommend testing dimensionality before assessing reliability, as well using multiple indices of reliability, such as model-based internal consistency, composite reliability, and omega and maximal reliability coefficients.
心力衰竭自我护理指数（SCHFI）被广泛使用，但可靠性问题一直很明显。克朗巴哈α系数通常用于评估可靠性，但这种方法假设量表是单维的。本文的目的是探讨SCHFI的维度和内部一致性可靠性。这是对参与在美国东北部和西北部进行的三项独立研究的629名成年心力衰竭患者的数据进行的二次分析。在使用验证性因素分析测试量表维度后，使用α系数和其他方法测试可靠性。验证性因素分析表明：（a）自我护理维持量表具有多维四因素结构；（b）自我护理管理量表具有双因素结构，但主要因素加载在一个共同的高阶因素上；（c）自我护理信心量表是单维的。使用与每个量表维度兼容的方法获得的三个量表的可靠性估计是足够的或较高的。分析结果表明，维度和可靠性问题不能分开。必须使用与量表维度一致的适当可靠性估计。就SCHFI而言，由于自我护理维持量表和自我护理管理量表的多维性，不应使用α系数来评估其可靠性。在进行心理测量评估时，我们建议在评估可靠性之前先测试维度，并使用多种可靠性指标，如基于模型的内部一致性、组合可靠性、ω系数和最大可靠性系数。
