Sleep disorders in advanced cancer patients: prevalence and factors associated

Sleep disorders have been invariably reported in cancer population. However, the prevalence of this problem in advanced cancer patients has never been assessed. The aim of this study was to evaluate the frequency of sleep disturbances in terms of quantity and quality, and possible associated factors.

A consecutive sample of patients admitted to a pain relief and palliative care unit were surveyed. Patients with severe cognitive problems or who were too ill were excluded. Epidemiological and clinical data, including the performance status, habits, relevant symptoms, and drug use were recorded. Patients were asked to answer a small questionnaire regarding their sleep, and duration and characteristics (nocturnal and diurnal hours slept, falling asleep, awaking, getting back to sleep, early awaking, restoring sleep, nightmares, feeling depressed or anxious). The level of information about the illness was also assessed.

Among the causes of admission, pain control was the main indication (about 58%). Of 123 patients surveyed, 30% slept less than 5 h. Women significantly slept more hours than men (p=0.042). Anxiety (p=0.045), falling asleep (p=0.003), awaking (p=0.035), early awaking (p=0.001), getting beck to sleep (p=0.021), and nightmares (p=0.034), were significantly associated with less hours slept. This relationship was highly significant for less restoring sleep, fatigue, and drowsiness ( p<0.0005). No differences were found for age (p=0.294), primary tumor (p=0.225), level of information ( p=0.529), Karnofsky status (p=0.539), depression (p= 0.095), confusion (p=0.074), possible causes of awaking (p= 0.881), use of opioids (p= 0.798), use of hypnotics (p= 0.197), other morbidities ( p=0.460), or use of alcohol or coffee (p= 0.141). Patients admitted for pain control and/or those receiving opioids more frequently had drowsiness (p=0.01) Patients with lower Karnofsky scores had more drowsiness and diurnal hours slept (p=0.01). Anxiety created more difficulties in falling asleep, produced a less restoring sleep, and nightmares. Depression was associated with early awaking, nonrestorative sleep, fatigue, and nightmares. Confusion was associated with fatigue and nightmares.

Sleep problems appear to be a significant issue for advanced cancer patients. Attention to sleep disturbance needs to be incorporated into the routine practice in palliative care evaluation.