Depressive symptoms, sleep disturbance and chronic illness are seldom studied together. Depression is higher in women and insomnia is a common sleep problem for women. Both are nurse-managed symptoms. This dissertation first proposes a theoretical nursing perspective of insomnia guided by four theoretical perspectives. The concepts from these perspectives were incorporated into a proposed model focused on mechanisms of insomnia and insomnia symptom experience.
The research involved a community-based sample of 347 healthy, ethnically diverse, premenopausal women between 40-50 years of age. The purpose was to describe patterns of depressive symptoms across time as a function of fixed demographic factors and time-varying biological and social factors, and describe the relationship between depressive symptoms and physical illness. The women with hypertension provided a group with a chronic physical illness.
Longitudinal data included the Center for Epidemiologic Studies - Depression (CES-D) scale, investigator-designed questionnaires about sociodemographics, medical history, and health problems, Pittsburgh Sleep Quality Index, social support subscale of the Interpersonal Relationships Inventory, and the health perception item from the Medical Outcomes Study Short Form. Biometric measures included: follicle stimulating hormone assays, blood pressure, and height and weight for calculating body mass index (BMI). Group comparisons used t-tests, ANOVA, chi square, and Mann-Whitney U.
Negative binomial regression was used for analysis of CES-D due to its skewed distribution in this sample. A significant model of predictors of CES-D scores was identified. Prevalence of depressive symptoms was 30% at study initiation and 26% at 30 months. Predictors of high CES-D scores were poor sleep quality, presence of chronic illness at 30 months, high BMI, and the interaction of time and poor sleep quality. Time, having a partner, positive social support and the interaction of time with low BMI predicted low CES-D scores.
A higher proportion of African American women scored > 16 on the CES-D. Number of health conditions, presence of chronic illness, and hypertension were significantly higher for women scoring >16 on CES-D compared to women scoring <16. Chronic illness was reported by 30.8% African Americans compared to 26.4% European Americans and 15.8% Latinas. Research and clinical implications were identified.