Extent of sleep problems and relationship with severity of chronic pain using three validated sleep assessment tools

OBJECTIVE: Chronic pain can impact on sleep, but the extent and nature of sleep problems in patients with chronic pain are incompletely clear. Several validated tools are available for sleep assessment but they each capture different aspects. We aimed to describe the extent of sleep issues in patients with chronic non-malignant pain using three different validated sleep assessment tools and to determine the relationship of sleep issues with pain severity recorded using the Brief Pain Inventory (BPI), a commonly used self-assessment tool in pain clinics. The BPI has a single question on the interference of pain on sleep and we also compared this with the validated sleep tools. DESIGN: Prospective, cross-sectional study. SETTING: Pain management clinic at a large teaching hospital in the United Kingdom. SUBJECTS: Adult patients (with chronic non-malignant pain of at least 3 months’ duration) attending clinic during a 2-month period. METHODS: Participants completed the Pittsburgh Sleep Quality Index (PSQI), the Pain and Sleep Questionnaire-3 (PSQ-3) and the Verran Snyder-Halpern (VSH) sleep scale, plus the BPI. Duration and type of pain, current medications and demographic data were recorded. RESULTS: We recruited 51 patients and 82% had poor sleep quality as shown by PSQIscores above five. PSQI (p = 0.0002), PSQ-3 (p = 0.0032), VSH sleep efficiency (p = 0.012), sleep disturbance (p = 0.0014) and waking after sleep onset (p = 0.0005) scores were associated with worse BPI pain scores. BPI sleep interference scores concurred broadly with the validated sleep tools. Median [range] sleep duration was 5.5 [3.0–10.0] hours and was also related to pain score (p = 0.0032). CONCLUSION: Chronic pain has a marked impact on sleep regardless of the assessment tool used. The sleep interference question in the BPI could be used routinely for initial identification of sleep problems in patients with chronic pain.