Relationship between pain intensity, sleep quality, and functional disability among patients with non-specific chronic low back pain: A multicentre cross-sectional study at two tertiary care hospitals in Colombo, Sri Lanka

Background & Aim: Low back pain represents a significant global public health concern, with approximately 90% of cases classified as non-specific. Understanding the interrelationships between pain intensity, sleep quality, and functional disability is crucial for developing comprehensive management strategies for patients with non-specific chronic low back pain (NSCLBP). This study aimed to examine the relationship among pain intensity, sleep quality, and functional disability in patients with NSCLBP attending selected government hospitals in the Colombo district.Methods: A descriptive cross-sectional study was conducted among 148 patients with NSCLBP (mean age 51.97 ± 13.40 years) attending rheumatology and rehabilitation clinics at the National Hospital Sri Lanka and Colombo South Teaching Hospital. Demographic data were collected using a semi-structured questionnaire. Pain intensity was assessed using the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2), sleep quality using the Pittsburgh Sleep Quality Index (PSQI), and functional disability with the Roland-Morris Low Back Pain and Disability Questionnaire (RMQ). Descriptive statistics and Pearson's correlation coefficient were used for statistical analysis.Results: The majority of participants (88.5%) reported poor sleep quality, with sleep latency identified as a major concern. A significant weak positive correlation was found between pain intensity and poor sleep quality (r=0.303, p