Measuring sleep disturbance in advanced cancer using the brief Pittsburgh sleep quality index (bPSQI)

Sleep disturbance is common among patients with cancer and is linked to significant morbidity, poorer quality of life and reduced survival in this population. The Pittsburgh Sleep Quality Index (PSQI) can identify poor sleep quality in this population, although a higher threshold value may be required compared to the general population. The brief PSQI (bPSQI), consisting of six of the original 19 items, offers a quicker and simpler tool. The bPSQI has demonstrated comparable accuracy in identifying poor sleep in the general population but remains unexplored in patients with advanced cancer. This observational study of 65 patients with advanced cancer reiterates the prevalence of sleep disturbance, demonstrates good internal consistency of the bPSQI and notes higher bPSQI scores with increasing subjective sleep-related distress. Although significant associations were noted between the bPSQI global score, individual bPSQI item scores and single-item sleep disturbance questions, the study cautions against the use of single-item questions in detecting sleep problems. Discrepancies were noted between subjective and objective sleep assessments. The findings support a higher threshold value for identifying poor sleep quality using the bPSQI. Although limited by a small sample size, the findings emphasize the need for further validation of the bPSQI in this population and to ensure that assessment methods align with research aims.