SINGAPORE - More than 40 per cent of Singaporeans do not get enough sleep on weekdays, according to the results of a study by SingHealth Polyclinics released on Tuesday (Jan 10).

Six in 10 Chinese participants had sufficient sleep. In comparison, around 40 per cent of Malays and Indians got adequate rest.

From February to June 2015, the team surveyed 350 adults at two polyclinics in Sengkang and Bukit Merah. Sleep time of less than seven hours was considered insufficient, which in the long run can affect the body's immune system, memory, concentration and daily functioning.

Factors affecting sleep were also studied. Respondents who used the computer or laptop to surf the web or play games in their bedrooms were more likely to lack sleep on weekdays.

However, more people who use mobile devices in bed were able to get enough sleep on weekends, compared with those who do not.

Dr Tan Ngiap Chuan, one of the authors of the study, said that they hoped to identify "modifiable factors" that doctors could use to advise their patients when faced with sleep inadequacy-related health problems.

Other aspects considered include consumption habits, employment, home environment and regularity of sleep patterns.

Results of the study will be disseminated to primary care physicians to improve efficiency in identifying problems and offering appropriate advice. The team will also continue analysing the data to explore the relationship between sleep inadequacy and other factors like snoring.