Assessment of screening tests for sleep apnea syndrome in the workplace

The Epworth sleepiness scale (ESS) is often used for screening of sleep apnea syndrome (SAS) in the workplace. We conducted pulse oximetry for workers of a large transportation company, who were selected based on their response to a questionnaire that included ESS and breathing pattern during sleep.

Pulse oximetry was performed for 803 of 3,761 male workers. A 3% oxygen desaturation index (ODI) >or=15 was defined to represent sleep disordered breathing (SDB). We evaluated the frequencies of severe snoring and sleep apnea in the past three months reported by the bed partner or a family member. The relationships between 3% ODI >or=15 and various parameters were analyzed.

Of the 715 workers with valid recordings, 3% ODI was >or=15 in 108. The prevalence of 3% ODI >or=15 was high among workers with a body mass index (BMI) >or=25 kg/m(2), or for whom severe snoring (>or=4 days/wk) or sleep apnea (>or=2 days/mo) was reported, but did not correlate with ESS scores. Multivariate analysis showed that 3% ODI >or=15 correlated significantly with BMI, and reported severe snoring and sleep apnea, but not ESS scores. The prevalence of 3% ODI >or=15 was high among obese workers. ESS scores did not correlate with 3% ODI >or=15, irrespective of obesity.

Our findings suggest that severe snoring, sleep apnea and BMI, but not ESS, are useful screening tools for SAS.