The assessment of sleep disturbances in cancer patients when measured with single items

Objective Sleep disturbances are frequently observed in cancer patients. In addition to validated multi-item scales for assessing sleep disturbances, there are also single-item measures. The aim of this study was to investigate the extent to which such ultra-short single-item assessments of sleep disturbances provide useful information in cancer patients. Methods This is a secondary analysis of a prospective multicenter study involving a sample of 970 patients with newly diagnosed cancer (mean age: 60.3 years; 46.8% women; mixed cancer diagnoses). We analyzed sleep disturbances using three single-item measures: the sleep items of the European-Organization-For-Research-And-Treatment-Of-Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and the Patient Health Questionnaire-9 (PHQ-9), and the dichotomous sleep item included in the Problem List of the Distress Thermometer. Samples of the general population were used as comparison groups. Results The sleep quality of the cancer patients was markedly poorer than that of the general population, with effect sizes between 0.67 and 0.74. The correlations between the sleep measures in the patients’ sample were between 0.61 and 0.74. The three sleep measures provided similar results regarding group differences based on sociodemographic and clinical variables, and their correlations with other scales of quality of life and mental health were also similar. Conclusion Despite the lower reliability of the single-item measures of sleep quality in comparison with multi-item scales, these single items can help identify groups of patients who are at increased risk of sleep disturbances and the factors that contribute to poor sleep.