Sleep is a natural biological and physiological phenomenon, and adequate sleep is critical for maintaining good health and well-being. Hospitalized patients require longer periods of high-quality sleep to promote faster recovery. However, the quality of sleep is often overlooked in the inpatient environment, where treatment and care are prioritized over quality sleep [1]. A majority of cancer patients experience sleep disorders to varying degrees throughout the treatment process. Cancer patients who receive anti-cancer treatment experience particularly severe sleep disorders during treatment; these disorders are also exacerbated as their treatment is prolonged [2].
Patients who receive hematopoietic stem cell transplantation (HSCT) are hospitalized for 3 to 4 weeks on average and often experience emotional problems, such as frustration, anxiety, and isolation, as a result of being separated from their families for isolation treatment during hospitalization [3]. The intense anti-cancer treatment, total radiation therapy, and side effects of HSCT are factors that contribute to disrupted sleep [4, 5]. Upon being admitted to the hospital, HSCT patients receive high-dosage of chemotherapy and a large amount of intravenous (IV) fluids during a roughly 1-week pre-transplantation conditioning period, and often experience side effects such as infection, gastrointestinal disorders, and pain during the immunosuppressed period, leading to sleep disorders [4]. Previous studies on HSCT patients reported that 70–80% of patients experienced sleep disruption and disorders during hospitalization and that 26% of patients were clinically diagnosed with insomnia [6, 7].
Sleep disorders may lead to undermined physical and mental functioning, chronic pain, respiratory failure, obesity, stress, and anxiety [8]. Sleep disorders in HSCT patients can also reduce their quality of life, cause tumor-related fatigue and a weakened immune system, diminish their cognitive function, exacerbate depression and anxiety, and in the worst cases may negatively affect the transplantation outcomes due to an increased inflammatory response [5, 9, 10].
Various objective and subjective measurement tools have been developed to evaluate sleep disorders. On the one hand, subjective self-reporting tools have traditionally been used to measure sleep disorders. On the other hand, objective physiological methods such as actigraphy have been recommended to identify sleep disorders and understand the various characteristics of sleep [11]. It would be ideal to use both subjective and objective measures to complement each other because patients’ self-reporting may not be sufficient to identify clinical sleep disorders, although self-reported data can be useful for understanding sleep patterns [7].
In a previous study that investigated the extent of sleep problems among HSCT patients 2 weeks after being hospitalized in the transplantation ward, 26% of patients experienced clinical insomnia and 74% of the patients had at least mild insomnia [6]. Another study that analyzed patients’ sleep quality during the immunosuppressed period reported that a majority of the patients showed sleep deprivation and irregular sleep patterns, which were highly correlated with the number of days hospitalized [7]. The same study reported that sleep deprivation and irregular sleep patterns were more prominent in objectively measured data than in subjectively perceived data reported by patients [7].
Upon reviewing previous studies, we found that most sleep quality research on patients undergoing HSCT used self-reporting measures, while no study used both objective and subjective methods to measure sleep patterns and compare the results. The present study used actigraphy as an objective measure together with the self-reported Insomnia Severity Index (ISI) as a subjective measure to evaluate the quantity and quality of sleep and investigated the differences between the two sets of results.