Sleep disturbance in cancer patients

Abstract

Sleep difficulty is a prominent concern of cancer patients, yet there has been no large study of the prevalence and nature of sleep disturbance in cancer patients. This cross-sectional survey study examined: (a) the prevalence of reported sleep problems in patients attending six clinics at a regional cancer centre; (b) sleep problem prevalence in relation to cancer treatment; and (c) the nature of reported insomnia (type, duration, and associated factors). For three months, all patients attending clinics for breast, gastrointestinal, genitourinary, gynecologic, lung, and non-melanoma skin cancers were offered a brief sleep questionnaire. Response rate was 87%; the final sample size was 982. Mean age of respondents was 64.9 years (SD 12.5). The most prevalent problems were excessive fatigue (44% of patients), leg restlessness (41%), insomnia (31%), and excessive sleepiness (28%). Chi square tests showed significant variation among clinics in the prevalence of most sleep problems. The lung clinic had the highest or second-highest prevalence of problems. The breast clinic had a high prevalence of insomnia and fatigue. Recent cancer treatment was associated with excessive fatigue and hypersomnolence. Insomnia commonly involved multiple awakenings (76% of cases) and duration ⩾6 months (75% of cases). In 48% of cases, insomnia onset was reported to occur around the time of cancer diagnosis (falling within the period 6 months pre-diagnosis to 18 months post-diagnosis). The most frequently identified contributors to insomnia were thoughts, concerns, and pain/discomfort. In a multivariate logistic regression analysis, variables associated with increased odds of insomnia were fatigue, age (inverse relationship), leg restlessness, sedative/hypnotic use, low or variable mood, dreams, concerns, and recent cancer surgery. This study provides new information about sleep-related phenomena in cancer patients, information which will be useful in planning supportive care services for cancer patients.

Introduction

Although sleep difficulty is associated with various medical conditions, including cardiovascular, respiratory, and painful musculoskeletal conditions (Foley et al., 1995; Gislason, Reynisdottir, Kristbjarnarson, & Benediktsdottir, 1993; Habte-Gabr et al., 1991; Katz & McHorney, 1998; Maggi et al., 1998; Moldofsky, 1986), little is known about sleep quality in people with cancer. It seems likely that the emotional and physical distress of cancer would be associated with sleep problems. Indeed, sleep difficulty is one of the most prominent concerns of cancer patients (Ginsburg, Quirt, Ginsburg, & Mackillop, 1995; Sarna, 1993; Whelan et al., 1997). In studies that focused specifically on sleep, Kaye, Kaye, and Madow (1983) found that 45% of 30 patients with advanced cancer reported difficulty staying asleep, and Silberfarb, Hauri, Oxman, and Schnurr (1993) found polysomnographic evidence of prolonged sleep latency and night-time wakefulness among 32 cancer patients. However, until now, there appears to have been no large survey study of the quality of sleep of cancer patients.

Knowledge of the nature and prevalence of sleep problems among cancer patients can provide the basis for new approaches to supportive care, because many sleep problems can be effectively treated. For example, given the effectiveness of psychological interventions for insomnia (Morin, Culbert, & Schwartz, 1994; Murtagh & Greenwood, 1995), quality of life stands to be improved substantially (within the limits imposed by illness) for cancer patients with insomnia. Improving sleep may have benefits for cancer patients beyond reversal of negative effects of insomnia on emotional, cognitive, and physical functioning. Evidence of links between sleep and natural killer cell activity (Dinges et al., 1994; Irwin et al., 1995; Irwin, Smith, & Gillin, 1992; Moldofsky, Lue, Davidson, & Gorczynski, 1989) raises the possibility that sound sleep may be important for immune defense against tumour cells.

This survey study was designed to gather sleep-related data that could ultimately inform the design of supportive care services at cancer centres. The primary objective was to examine the nature and prevalence of sleep problems in patients attending a regional cancer centre, with special attention to insomnia. The specific goals were to examine: (a) the prevalence of reported sleep problems in patients attending six clinics at a regional cancer centre; (b) the prevalence of reported sleep problems in relation to recent cancer treatment; and (c) the nature of reported insomnia, including type, duration, identified contributors, and associated variables.