To the Editors:
Pepin et al. 1 recently published a very interesting study of residual excessive sleepiness (RES) in 502 patients with obstructive sleep apnoea treated successfully with continuous positive airway pressure (CPAP). They concluded that a significant percentage (about 6–12%, depending on inclusion criteria) had RES. They concluded that, since about 230,000 French patients are on CPAP, a minimum of 13,800 might suffer from RES, as defined by an Epworth Sleepiness Score (ESS) ≥11. In 2007, we looked at the same issue in 572 patients with OSA from the Oxford Sleep Clinic 2, but compared them with a community-based sample of 525 control subjects 3. What was striking, was that there was no difference between the patients and the control subjects, implying that patients on CPAP had no greater a proportion with RES than the general population. This was not to say that the subjects in the control population were normal, there would have been subjects with a variety of sleep disorders on statistical grounds alone. The point we felt important was that the patients on CPAP appeared no different, thus arguing against there being any specific residual problem in patients with OSA receiving successful CPAP treatment. I have redrawn the graph (% of subjects versus ESS quintile) from our 2007 paper and included as a third column the raw data from Pepin et al. 1 (fig. 1⇓). Again, what is striking is that the ESS distribution from the French patients on CPAP is virtually identical to the Oxford groups of both CPAP patients and control subjects. The purpose of this correspondence is again to question whether sleepiness in successfully treated patients with OSA is any different to “normal”.
Statement of interest
None declared
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