OBJECTIVETo study the value of Epworth sleepiness scale in assessment of obstructive sleep apnea hypopnea syndrome (OSAHS) severity.

METHODSThe polysomnography (PSG) data of 620 suspected OSAHS patients from Jan. 2000 to Dec. 2003 were retrospectively analyzed. There were 556 males and 64 females, and their age ranged from 21 to 79 years (median 45.0 years). Of the all 620 patients, the median of the weight was 82.0 kg ( range 50 to 130 kg), median of height was 172.0 cm (range 147 to 178 cm), median of body mass index was 28.0 (range 18.5 to 42.9), median of apnea-hypopnea index (AHI) was 37.2 (range 0 to 126.1), median of lowest arterial oxygen saturation (LSAT) was 0.75 (range 0.21 to 0.93), median of ESS was 13.0 (range 0 to 24). OSAHS was diagnosed in 513 patients and simple snorer was diagnosed in 107 patients by PSG. All the patients filled in ESS questionnaire in sleep disorder centre before PSG.

RESULTSThe correlation coefficients of the ESS and AHI, LSAT was -0.314 and -0.312 respectively (P <0. 05). The median of ESS in severe OSAHS group was higher than that in simple snorer, mild and moderate OSAHS groups (P < 0.001), but no difference was found among the simple snorer, mild and moderate OSAHS groups (P < 0.05). The median of ESS in severe hypoxemia group was higher than that in no, mild and moderate hypoxemia groups (P < 0.001), but no difference was found among no, mild and moderate hypoxemia groups (P > 0.05).

CONCLUSIONSThe Epworth sleepiness scale has little value in assessment of OSAHS severity. A new sleepiness scale method which is suitable for Chinese should be made.