Sleep behaviour of old people in Hong Kong

Abstract

Complaints of poor sleep and changes in sleep-wake patterns are common among old people. An understanding of the common 24-hour sleep-wake patterns and sleep satisfaction among old people is essential for effective sleep management. To this end, an exploratory study was conducted to examine the phenomenon. A set of valid and reliable questionnaire in Chinese was developed for recording the habitual sleep-wake patterns of local old people. A pilot study with 30 participants was conducted prior to the actual study. There were 206 community residing old people participated in the first part of the study. In the second part of the study, forty of them (21 men and 19 women) also had their objective and subjective sleep-wake patterns recorded by wrist actigraph and sleep log respectively for 48 hours. In addition, the 6-sulphatoxymelatonin (aMT6s) levels of the 40 subjects were studied. It was found that majority of the old people (92.2%, n=190) had regular bedtime schedules. Most of them (68.9%, n=142) went to bed between 21:00 hours and 23:00 hours. Eighty-six percents of the subjects (n=177) had their final awakening before 07:00 hours. Nearly half of the subjects (49.5%, n=102) arose from bed immediately upon final awakening. All of the data in the actigraphic recording, sleep log and sleep questionnaire showed that majority of the old people could not maintain sleep throughout the night. The prevalence of self-reported sleep disturbance was 39.3% (n=81). Nearly half of the subject (44.2%, n=91) would like to have improvement in sleep quality using non-pharmacological methods. Difficulty in maintaining sleep was their main concern. Nocturia was reported as the major factor contributing to sleep interruption in both male and female subjects. The actigraphic recording revealed that the average sleep efficiency of the 40 subjects was 84.5%. In the first part of the study, majority of the subjects (84.5%; n=174) reported that they had either intentional or unintentional naps. The actigraphic recording however showed that as many as 47.5% (n=19) and 62.5% (n=25) of the subjects were not aware of their unintentional nap in the afternoon and in the evening respectively. The total nap time based on actigraph accounted for 12.1% of the total sleep time over 24-hour period. There was association between sleep disturbance and intentional nap. The consumption rates of caffeine, alcohol, tobacco and milk were very similar across the two subject groups who had or had not been suffering from sleep disturbance. The actigraphic recording also revealed that the average sleep efficiency of those who had alcohol and caffeine consumption was not lower than that of the remaining subjects. The urinary aMT6s levels (throughout the nocturnal bed time) of the subjects (n=35) ranged from 6.3 pmol/ml to 48.1 pmol/ml. The mean urinary aMT6s level of the subjects was 23.1 pmol/ml. There was no gender and gender difference in the aMT6s level. The mean aMT6s level was not correlated with sleep efficiency based on actigraph. The findings of the study and their implications to local nursing practice were discussed. Recommendations on future directions of evidence-based management of sleep disturbance were outlined.