Modeling hot flushes and quality of life in breast cancer survivors

Abstract

Objectives To evaluate the relationships among measures of hot flushes, perceived hot flush interference, sleep disturbance, and measures of quality of life while controlling for potential covariates (patient and treatment variables).

Methods Breast cancer survivors (n == 395) due to receive aromatase inhibitor therapy provided demographic information, physiological hot flush data via sternal skin conductance monitoring, hot flush frequency via written diary and electronic event marker, hot flush severity and bother via written diary, and questionnaire data via the Hot Flash Related Daily Interference Scale, Pittsburgh Sleep Quality Index, the EuroQOL, Hospital Anxiety and Depression Scale and the Center for Epidemiologic Studies Depression Scale.

Results Confirmatory factor analysis supported a two-factor model for hot flush symptoms (frequency and severity). Although there was strong convergence among self-reported hot flush measures, there was a high degree of unexplained variance associated with physiological measures. This suggests that self-report and physiological measures do not overlap substantially. The structural model showed that greater hot flush frequency and severity were directly related to greater perceived interference with daily life activities. Greater perceived interference, in turn, directly predicted greater sleep disruption, which predicted lower perceived health state and more symptoms of anxiety and depression.

Conclusions Findings suggest hot flush interference may be the most appropriate single measure to include in clinical trials of vasomotor symptom therapies. Measuring and ameliorating patients' perceptions of hot flush interference with life activities and subjective sleep quality may be the most direct routes to improving quality of life.

Key words:

• HOT FLUSHES
• MENOPAUSE
• BREAST CANCER
• QUALITY OF LIFE
• STRUCTURAL MODEL

Conflict of interest  Nil.

Source of funding  Supported in part by a Pharmacogenetics Research Network Grant ## U-01 GM61373 that supports the Consortium on Breast Cancer Pharmacogenomics (COBRA), a Clinical Pharmacology training grant 5T32-GM08425 from the National Institute of General Medical sciences, National Institutes of Health, Bethesda, MD, Indiana University GCRC grant M01RR00750 from the National Institutes of Health, Bethesda, MD, University of Michigan GCRC grant M01-RR00042 from the National Institutes of Health, Bethesda, MD, Johns Hopkins University School of Medicine GCRC grant M01-RR00052 from the National Institutes of Health, Bethesda, MD, and by the Fashion Footwear Charitable Foundation of New York/QVC Presents Shoes on Sale™.