Alterations and Interdependence in Self-Reported Sleep-Wake Parameters of Patient-Caregiver Dyads During Adjuvant Chemotherapy for Breast Cancer .

PURPOSE/OBJECTIVES: To longitudinally explore changes, similarities, differences, and interrelations in the sleep-wake parameters of patient-caregiver dyads throughout adjuvant chemotherapy for breast cancer.
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DESIGN: Observational, repeated-measures, dyadic study.
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SETTING: Four ambulatory oncology clinics in Scotland.
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SAMPLE: 48 dyads consisting of patients and their primary informal caregivers.
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METHODS: Four dyadic, self-reported sleep-wake assessments took place before chemo-therapy (T0), during chemotherapy cycles 1 (T1) and 4 (T2), and after chemotherapy (T3). Dyads completed the Pittsburgh Sleep Quality Index. Multilevel hierarchical linear modeling was used to explore dyadic data.
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MAIN RESEARCH VARIABLES: Perceived sleep quality, sleep onset latency (SOL), total sleep time, habitual sleep efficiency, wake after sleep onset, daily disturbance, daytime napping duration, overall sleep-wake impairment.
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FINDINGS: The majority of dyads had at least one poor sleeper throughout the study; 25%-35% were dyads of concurrent poor sleepers. Curvilinear patterns of change were evident for patients' (but not caregivers') sleep-wake parameters, steadily deteriorating from pre- to midtreatment, then leveling off close to baseline. Average trajectories were significantly different between the dyad members but indicative of a trend for concurrent deterioration at T2. Dyad members' perceived sleep quality, SOL, and overall sleep-wake impairment were closely interrelated; wake variables remained uncoupled.
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CONCLUSIONS: Despite overall differences in magnitude, sleep problems may be concurrently present in both dyad members, covary, and peak midway through chemotherapy. 
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IMPLICATIONS FOR NURSING

Dyadic sleep assessments can shed light on potential areas of sleep interaction to enable interventions to support care dyads at risk of sleep distress during chemotherapy for breast cancer.