Structural and construct validity of the Quality of Life Scale among Canadian women with histories of intimate partner violence.

Abstract

Objectives:To evaluate the structural and construct validity, and internal consistency of the Quality of Life Scale among Canadian women with histories of intimate partner violence.Methods:Consistent with COSMIN Guidelines, a secondary analysis was conducted using data from a community sample of 250 adult (over 18 years) Canadian women with histories of partner violence and who participated in Wave 5 of the longitudinal Women’s Health Effects Study. Data were collected 4 years after baseline using structured interviews that included the Quality of Life Scale and two mental symptom scales (Center for Epidemiological Depression Scale and Davidson Trauma Scale) used to assess construct validity of the Quality of Life Scale.Results:Confirmatory factor analysis in MPLUS 8 with maximum likelihood estimation supported the hypothesized unidimensional structure of the 9-item Quality of Life Scale based on acceptable fit indices. Internal consistency, estimated using Cronbach’s alpha and composite reliability, were .91 and .92, respectively, with item-total correlations ranging from .46 to .84. Inter-item correlation coefficients (range = .30–.79), suggesting that all items contribute to the total score. As hypothesized, the quality of life total score was negatively related to the total scores on both the Center for Epidemiologic Studies-Depression (r = –.739) and Davidson Trauma Scale (r = –.537), providing evidence of construct validity of the Quality of Life Scale.Conclusion:The Quality of Life Scale is a brief, reliable, valid, unidimensional self-report measure appropriate for use with women who have experienced partner violence. By addressing an important measurement gap, results of this study have potential to advance research on women’s quality of life in the context of partner violence, including improving the evaluation of a growing body of advocacy and health interventions designed to support women’s healing and well-being.