Background and purpose

To investigate the prevalence and determinants of daytime sleepiness in an Asian multi-ethnic population. Cross-sectional survey based on a questionnaire in multi-ethnic Asian adult population of Singapore (2.4 million).

Patients and methods

Measured frequency of excessive daytime sleepiness (EDS), socio-demographic status, sleep duration, perceived sleep insufficiency, frequent awakenings, difficulty falling asleep, snoring, breathing pauses, GHQ-12, shift work, solvent exposure at work, substance use, medications, and chronic diseases in random sample of 2,298 adults, aged 20-74 years, representing Chinese, Malays and Indians.

Results

Among the respondents, 10.8% reported usually feeling sleepy in the daytime, and 9.0% were classified as having EDS. Marked ethnic difference was observed, with higher rates of EDS in Malays and Chinese, compared to Indians. Increased risk of EDS was associated with perceived sleep insufficiency; snoring and breathing pauses; shift work and solvent exposure at work; psychiatric morbidity and chronic diseases, particularly chronic rhinitis; and medications with sedating effects.

Conclusions

Daytime sleepiness is associated with a multiplicity of highly prevalent risk factors in the community, including sleep behavior, breathing-, work- and medically related factors. Significant ethnic differences, which were not explained by these factors, were observed between Chinese, Malays and Indians.