Sleep Disorders Independently Linked to Higher Medical Costs in Low Back Pain

Peer Reviewed

Sleep disorders are significantly and independently associated with greater medical costs and healthcare visits for low back pain, according to data from a prospective observational cohort study published online ahead of print in Spine. The findings emphasize the importance of screening patients with low back pain for sleep disorders and managing sleep disturbances early in the treatment course, the study authors noted.

man with insomnia awake in his bedThere are several tools with satisfactory psychometric properties that can screen patients for sleep disorders and manage both sleep disturbance and low back pain. Photo Source: 123RF.com.

“We know that there is a bidirectional relationship between sleep and pain, in that we’ve seen that patients with disordered sleep have higher levels of pain, and patients with higher levels of pain are more likely to have disordered sleep,” lead author Daniel Rhon, DSc, told SpineUniverse. “This study went even further to show that disordered sleep strengthened the relationship between pain, disability, and downstream healthcare utilization. Patients with a sleep disorder sought out greater amounts of additional medical care specifically for their low back pain if they also had a sleep disorder.”

“This was for the entire 2-year period after their participation in this study, so not just in the short-term,” said Dr. Rhon, who is the Director of the Primary Care Musculoskeletal Research Center at Brooke Army Medical Center.

Manage Sleep Disorders Early in the Treatment of Low Back Pain

“A key question to ask every patient with low back pain is whether they have sleep disturbance,” commented Christopher C. Ornelas, MD, Assistant Professor of Orthopaedic Surgery at the USC Spine Center at the Keck School of Medicine of the University of Southern California in Los Angeles. “This study demonstrates that if sleep disorders are not managed initially, patients can have long-term problems that will cost more money and time to treat.”

In addition, the presence of a sleep disturbance can alter what medications are used to treat low back pain as some medications—such as muscle relaxants and membrane stabilizers (eg, carbamazepine, gabapentin/pregabalin, topiramate)—have sleepiness as a side effect and can be used to help regulate the sleep cycle as well as manage pain, Dr. Ornelas told SpineUniverse.

Prospective Observational Cohort Study

Dr. Rhon and colleagues prospectively examined 757 patients (68% male; mean age, 35.1 years) with low back pain enrolled in a one-time pain self-management class held at a large US military hospital serving military personnel and their families between March 2010 and December 2012. The patients provided baseline data on disability, pain intensity, and sleepiness, and were prospectively followed for one year to determine healthcare utilization (visits and cost) for low back pain.

In general, patients reported modest levels of pain and disability, with mean pain scores of 2.4 (on a 0-5 scale), and mean Oswestry Disability Index (ODI) scores of 18.6 (on a scale from 0-100).

Sleep Disorders Found in One-Quarter of Low Back Pain Patients

One-quarter of these patients with low back pain (27%) had sleep disorders, most commonly insomnia (16%) and isolated sleep symptoms (6%).

In multivariate analyses, with greater disability, greater pain intensity, presence of a sleep disorder had a significant independent effect on low back pain-related healthcare visits and costs. In addition, sleep disorders moderated the relationship between disability and healthcare visits in that patients with greater disability in combination with a sleep disorder had the highest predicted number of visits for low back pain.

“Interpretation of the main effects for presence of a sleep disorder indicate that at an Oswestry score of 20, for example, we would expect those with a sleep disorder to have low back pain costs of approximately $1,254, whereas those without a sleep disorder would have costs of approximately $766, on average and with all other variables held constant,” according to the authors. A larger cost difference was seen for patients with an ODI score of 60 with costs estimated at $3,147 and $1,923 for patients with and without a sleep disorder, respectively.

Screening for Sleep Disorders in Low Back Pain Patients

“The findings of this study highlight the relevance of screening for sleep issues,” Dr. Rhon said. “Because pain control is a high priority for surgeons postoperatively, they should consider quality of sleep with their patients, definitely before surgery, but most likely after surgery as well.”

“There are several tools with satisfactory psychometric properties (validated measures) that can help screen for sleep disorders (Insomnia Severity Scale, Pittsburg Sleep Quality Index, PROMIS sleep scales, etc),” Dr. Rhon told SpineUniverse. “The guidance on next steps will vary on the clinical scenario and setting, but what we are trying to do in our setting is approach this more holistically by including sleep medicine specialists in the management plan.”

“This doesn’t apply to every patient, of course, so working with patients and other members of the medical team to determine what is a good cut-off for a referral and being ready to provide appropriate self-management strategies to those who don’t need a referral is a good place to start.

Key questions to ask patients with low back pain during initial evaluations include the following, according to Dr. Ornelas:

  • Does the pain interrupt your sleep?
  • Do you wake up due to the discomfort?
  • Do you have trouble falling asleep because you can’t position correctly due to the discomfort?

In addition, “it is important to determine whether the patient has a pure sleep disorder and if they are taking sleep medications,” Dr. Ornelas said, adding that this information will alter what medications are tried next. “For patients who present with low back pain and an untreated sleep impairment, I would put them on muscle relaxants or membrane stabilizers for a period of 30 to 60 days to help regulate the sleep cycle at the beginning of treatment, while we are trying to manage the pain.”

“It is also important to ask patients about sleep hygiene and educate them that you may be able improve low back pain at a faster rate or to a significantly greater degree if you treat the sleep disorder from the get-go,” Dr. Ornelas said. “It is important for patients to understand that there are downstream effects of sleep impairment over time.”

Health consists of many overlapping constructs and determinants, and the need to screen for and address other components of health, which might indirectly influence the outcomes a surgeon is hoping for, may be a good way to improve outcomes, especially in challenging patients who are more susceptible to comorbid conditions and chronic pain,” Dr. Rhon said.

The Effect of Pain Medications on Sleep

Dr. Rhon and colleagues did not take into account specific medications used to reduce pain/muscle spasms in low back pain (eg, cyclobenzaprine, gabapentin, opioids) when evaluating patients for sleep disorders. Thus, it is unclear what association, if any, these medications may have on the study findings.

“Studies suggest that disordered sleep does affect the pain experience,” Dr. Rhon said. “Poor sleep is associated with loss of pain inhibition, induces generalized hyperalgesia, amplifies pain reactivity, and expands the temperature range for classifying a stimulus as painful, etc. However, these same patients, who may also have disordered sleep, are seeing us for pain, which we are conditioned to treat by default with medications.”

Dr. Ornelas noted that use of oral or injectable corticosteroids can sometimes disturb patients’ sleep. “If oral steroids are given as a short steroid burst for approximately 6 days, patients may feel more awake or agitated, especially during the first few days of treatment,” Dr. Ornelas said. “Make sure that patients take oral steroids earlier in the day as opposed to right before sleep.”

In some cases, “we pair corticosteroid injections with either a muscle relaxer or membrane stabilizer so that we can counteract the effect on sleep, but the side effect is generally short lived with injectable steroids and these additional treatments are not always needed.”

Opioid use is another important consideration. “We know from other studies that even a single dose of opioids can alter sleep architecture and prolonged use can limit the amount of quality sleep an individual gets,” Dr. Rhon explained. “Opioids are a major contributor to nocturnal hypoxemia and apnea. Acute use of opioids can increase REM latency, decrease REM sleep time, decrease overall sleep time and decrease sleep efficiency (REM is where restorative sleep occurs). Ironically, we use opioids to manage pain, but then they can disrupt sleep, which can also lead to lower pain tolerance.”

“Clinicians should consider all of this when formulating their pharmacological pain management plans,” Dr. Rhon told SpineUniverse. “We often think only of the direct adverse effects of medications, but not always of the indirect health effects of some of these same medications. Thus, it would certainly be helpful to consider both prior and future medication use in the evaluation of these patients. We have found in some of our other work that patients with an insomnia diagnosis before surgery were much more likely to be chronic opioid users after surgery than patients without insomnia.”

“More and more attention is being shifted to this relationship between sleep and pain,” Dr. Rhon concluded. As one expert noted, sleep is “a novel therapeutic target for pain management within and outside the clinic, including circumstances where sleep is frequently short, yet pain is abundant (eg, the hospital setting).”1
 

Disclosures
Dr. Rhon has no relevant disclosures.

Updated on: 08/01/19
Continue Reading
Patterns in Back Pain Over Time: Who Recovers and Who Persists?
Daniel Rhon, DSc
Director
Primary Care Musculoskeletal Research Center
Brooke Army Medical Center
Christopher Ornelas, MD
Assistant Professor, Clinical Orthopaedic Surgery
Keck School of Medicine, University of Southern California
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