The presence of a sleep disorder has a “significant and unique effect” on back pain-related healthcare use—beyond the impact of pain intensity, disability, and other factors, according to a study recently published in Spine. Authors Daniel Rhon (Brooke Army Medical Center, San Antonio, USA) and colleagues believe that assessing sleep disorders in patients with back pain “could provide an important indication of risk for high pain-related healthcare use.”
The study included 757 patients with low back pain attending self-management classes at a US military hospital. More than two-thirds of patients were men; over 80% were military service members.
The researchers assessed standard scores for pain intensity and disability, along with the presence of diagnosed sleep disorders and daytime sleepiness. These factors were evaluated for association with the amount of healthcare for low back pain (total number of medical visits and costs of related care) in the year after the self-management classes.
As a group, the patients had relatively mild back pain: the average pain score was 2.4 out of 5 and average disability score 18.7 out of 100. However, 26% had a diagnosed sleep disorder—most commonly insomnia.
“The number of visits for low back pain was significantly associated with pain intensity, disability, and history of sleep disorder,” Rhon and colleagues write. Pain, disability, and diagnosed sleep disorders were also linked to increased costs for treating back pain. Daytime sleepiness, although a key symptom of sleep disorders, was unrelated to healthcare visits or costs.
Sleep disorders were associated with higher low back pain-related healthcare visits and costs at all levels of pain and disability. For example, at a disability score of 20, the average number of low back pain-related healthcare visits was 5.4 for patients with sleep disorders versus 3.5 for those without sleep disorders. At the same disability score, average healthcare costs were about US$1,254 for patients with sleep disorders versus US$766 for those without.
The impact of sleep disorders was even greater at higher levels of pain and disability. However, the study found no “moderating effect”—sleep disorders did not explain the increases in healthcare visits or costs for patients with higher pain or disability scores.
Low back pain is a very common condition and a major contributor to high levels of healthcare use and increased costs. Previous studies have suggested that sleep quality may contribute to outcomes for patients with musculoskeletal pain conditions, including back pain.
The new findings show that patients with diagnosed sleep disorders have higher healthcare use and costs for low back pain, independent of the effects of pain intensity and disability scores. Rhon and coauthors write, “The presence of sleep disorders is not often evaluated during the clinical management of low back pain, but could provide an important indication of risk for high pain-related healthcare use.” That may be especially important with new healthcare reimbursement models emphasising higher-quality, lower-cost care.
Rhon and colleagues call for further research to clarify how sleep disorders affect the outcomes of low back pain—including studies of patients with higher pain intensity and disability scores. They also discuss possible treatment implications, such as appropriate screening for disordered sleep earlier in the care management pathway. This also includes the need for clinical decision aids that improve management of disordered sleep for patients with back pain, as well as thresholds for referral to a sleep specialist.