Abstract
Human spend one quarter of life in sleep. However, not everyone gets adequate sleep as there are factors that can disturb sleep that can lead to insomnia. One of the behavioural factors that can influence sleep is the consumption of caffeinated drinks. The purpose of the present study was to identify the behavioural influential factors for insomnia such as consumption of caffeinated drink (tea and coffee). The participants were 500 working adults aged 20-60 years in Georgetown, Penang who were relatively healthy. The participants were recruited through convenience sampling at various working places. Athen’s Insomnia Scale (AIS) was administered to screen on insomnia symptoms. 135 respondents who had insomnia symptoms were assessed on consumption of caffeinated drink in daytime and close to bedtime. The results revealed that consumption of caffeine close to bedtime was significantly correlated with insomnia. The daytime consumption had no significant correlation to insomnia. The findings of the present study provide information that caffeinated drink can affect sleep. This may help to increase the awareness of practicing healthy behaviour to reduce caffeine in one’s diet as a preventive measure against insomnia.

Key words: insomnia, caffeinated drink, adults, daytime, night, bedtime.