Where's the Evidence?
An AASM Task Force recently reviewed available literature and published updated Clinical Practice Guidelines for circadian rhythm sleep disorders. 1 The previous guidelines were published in 2007. 2 The update employs the GRADE method currently in use to develop AASM practice parameters. The authors cite 200 articles and used 3 printed pages of search terms. But, alas, the evidence used in developing these guidelines can be charitably described as weak. This stands in stark contrast to the robust and exciting human and animal research in basic circadian rhythms, ably reviewed by Sack and colleagues 3 as background for the 2007 guidelines paper and updated by the task force.
The prevalence of circadian rhythm disorders is difficult to estimate. Many delayed sleep phase patients are treated as if they have sleep onset insomnia, and it is likely that most advanced sleep phase patients do not seek treatment. Jet lag and shift work are prevalent but, again, most patients do not seek treatment. The minimal representation of these disorders in sleep clinics probably underestimates their impact on productivity and as a comorbidity in a variety of disorders.
The Task Force highlighted a few new studies of melatonin and bright light therapy in children and adolescents; these studies impact recommendations for treatment for young delayed sleep phase patients having difficulty adjusting to early school start times. An accompanying editorial bemoans the lack of funding for clinical research. 4
One of the few disorders to have a treatment tested using rigorous randomized, placebo-controlled research is "non-24 hour sleep wake disorder." The FDA-approved medication that was tested for this disorder, tasimelteon, was found to be effective but slightly less so than over-the-counter melatonin. This illustrates what may be the key issue in treatment of circadian rhythm sleep disorders: effective treatments are available without prescription and are unlikely to generate the level of revenue necessary to fund rigorous experimental studies.
Since experimental research is limited and not likely to expand, correlational studies may be helpful in shaping future clinical guidelines. Standardized outcomes measures and a centralized data base could yield a consensus on the most frequently prescribed treatments and provide measures of their efficacy. The AASM convened task forces to identify standardized quality measures for restless legs syndrome, insomnia, narcolepsy and adult and pediatric patients with obstructive sleep apnea. 5 Unfortunately, circadian rhythm sleep disorders did not make the cut this year - but who knows, maybe next year? The Cubs are playing baseball in October. I think this means that anything can happen.
1. Auger RR, Burgess HJ, Emens JS, Deriy LV, Thomas SM, Sharkey KM. Clinical practice guideline for the treatment of intrinsic circadian rhythm sleep-wake disorders: advanced sleep-wake phase disorder (ASWPD), delayed sleep-wake phase disorder (DSWPD), non-24-hour sleepwake rhythm disorder (N24SWD), and irregular sleep-wake rhythm disorder (ISWRD). An update for 2015. J Clin Sleep Med 2015;11(10):1199 -1236 .
2. Morgenthaler TI, Lee-Chiong T, Alessi C, et al. Practice parameters for the clinical evaluation and treatment of circadian rhythm sleep disorders. An American Academy of Sleep Medicine report. Sleep 2007;30:1445-59.
3. Sack RL, Auckley D, Auger RR, et al. Circadian rhythm sleep disorders: part I, basic principles, shift work and jet lag disorders. An American Academy of Sleep Medicine review. Sleep 2007;30:1460-83.
4. Auger RR, Burgess HJ, Emens JS, Deriy LV, Sharkey KM. Do evidence-based treatments for circadian rhythm sleep-wake disorders make the GRADE? Updated guidelines point to need for more clinical research. J Clin Sleep Med 2015;11(10):1079-1080.
5. Morgenthaler TI, Aronsky AJ, Carden KA,Chervin RD, Thomas SM, Watson NF. Measurement ofquality to improve care in sleep medicine. J Clin Sleep Med2015;11(3):279-291.