Catching underyling systemic diseases early, that may mimic mechanical pain, is always a concern during our evaluations. This is especially important now that Direct Access is more readily accessible and unfortunately the medico-legal prevalence in our society. Night pain has typically been attribued to a pathological origins such as tumors, metastatic disease and other serious viscera disorders.
How informative is night pain in the subjective questioning? We have historically been taught this is a red flag and a high concern of a non-mechanical origin. So, we go off and think diagnostic tests need to be ordered to cover our bottoms. Well, not so fast. Remember, the purpose of these tests is if it will make a difference in the treatment and considering ~80% of the population will have LBP sometime in their life, this would get highly expensive. How can we make this decision more reasonable?
Let’s look at the research.
A few studies shown below demonstrate the prevalance of night pain with mechanical low back pain.
-Biering-Sorensen found that night pain was present in 17% of males and 30% of females.
-Boissonnault & Di Fabio found that 53% of patients reported pain severe enough to wake them from sleep.
This is pretty high prevalence (1 in 2 persons) considering the diagnostic groups studied were very commonly seen in our practices; disc disease and mechanical low back syndrome.
The authors quoted, “Therefore, despite the association of night pain with pathological origins of back pain, it is questionable that the presence of night pain alone has any diagnostic value.”
-Farrell and Twomey reported 22 of 48 subjects (45%) with low back pain reported night pain.
-Jayson et al found that 73 of 188 patients (38%) with low back pain experienced night pain.
From the combination of these studies, the prevalence of night symptoms with LBP is pretty common.
On the flip side:
Roach et al found that “The combination of symptoms that includes the three sleep disturbance symptoms (pain wakes from sleep, need sleep medications, or unable to sleep) and pain worsened by walking has a sensitivity of .87”, but also a specificity of .50.
-Meaning, 87% of serious low back pain patients (non-mechanical) will report at least one of these symptoms.
-Also meaning, 1/2 of non-serious LBP patients (mechanical) will not report these symptoms and 1/2 of serious LBP patients will not report these symptoms.
Now, I’m sure you can find multiple other studies negating or confirming this information. As much as we would like to rely on EBM showing sensitivity and specificity values for screening, they are just not available. You just have to use clinical reasoning and judgment.
Stay tuned (or sign up for email alerts at top-right of page) for part 2 of this post.
If you have had a case in which a patient has been referred or even walked off the street with a non-mechanical origin, what are your thoughts on night pain? Did you find this to be a screen for further medical follow-up? I would like to hear about your clinical experiences.
Ross MD, Boissonnault WG. JOSPT. Guest Editorial. Red Flags: To Screen or Not to Screen? 2010; 40(11); 682-684.
Biering-Sorensen F: A prospective study of low back pain in a general population. Scand J Rehabil Med 15:81-88, 1983.
Farrel JP, Twomeny LT: Acute low back pain: Comparision of two conservative treatment approaches. Med J Aust 1(4): 160-164, 1982.
Jayson MI< Sims-Willaims H, Young S, Baddely H, Collins E: Mobilization and manipulation for low back pain. Spine 6(4): 409-416, 1981.
Roach KE, Brown M, Ricker E, et al. The Use of Patient Symptoms to Screen for Serious Back Problems. JOSPT. 1995; 21(1), 2-6.