Sleep problems and psychological distress in family members of patients with hematological malignancies in the Japanese population.

Patients with cancer frequently suffer from insomnia symptoms, and additionally, their family members also often experience these symptoms. The aim of this study was to investigate the prevalence of insomnia symptoms in both family members and patients with hematological malignancies. We conducted an observational cross-sectional study using a clinical self-reported questionnaire for sleep conditions, depressive symptoms (two-question method), and worries (five items that originated from the Brief Cancer Worry Inventory).