Cluster analysis of midlife women's sleep-related symptoms: racial/ethnic differences

Abstract

Objective: The purpose of this study was to identify clusters of midlife women by sleep-related symptoms in multiethnic groups and to examine racial/ethnic differences in the clusters. Methods: This secondary analysis was conducted on data from 1,054 midlife women who participated in two cross-sectional descriptive national Internet surveys. The instruments included questions on background characteristics, health, and menopause status, and the Sleep Index for Midlife Women. The data were analyzed using hierarchical clustering methods, chi(2) test, analysis of variance, and multinomial logistic regression analyses. Results: A four-cluster solution was adopted: cluster 1 (low total symptoms group), cluster 2 (moderate physical and psychosomatic symptoms group), cluster 3 (moderate psychological symptoms group), and cluster 4 (high total symptoms group). There were significant differences in education, employment status, family income, social support, country of birth, race/ethnicity, body mass index, perceived general health, diagnosed disease, access to health care, and menopause status among clusters (P<0.05). In cluster 1 only, there were significant racial/ethnic differences in the total number of total severity scores for physical symptoms (P<0.01). When racial/ethnic differences in individual symptoms in each cluster were determined, there were no consistent racial/ethnic differences. Conclusions: Researchers need to consider that racial/ethnic differences could be prominent in midlife women with low sleep-related symptoms.