Age and Lateral Sleep Position: A Pilot Study

Abstract

Purpose: Previous research, undertaken using a Super 8 camera and non-continuous data, has reported that with increasing age, people are more likely to sleep in the right lateral position. It has been postulated that this is due to age related alterations in cardiovascular function. This pilot study was undertaken to determine if collection and analysis of continuous sleep data was a feasible method for further investigation of this topic and to determine the sample size required for an adequately powered study. Increased understanding of age related changes in sleep position may provide valuable information to improve sleep quality and nursing care of the elderly person. Method: Research at the Centre for Sleep Research, University of South Australia, investigated the association between age and sleep position. Infra-red illumination and video cameras recorded the sleep patterns of 12 subjects for two nights. Videos were examined and the amount of time spent in each sleep position was calculated in seconds. Results: In a one-way analysis of variance, sample sizes of 19, 19, and, 19 are necessary from the three age groups whose means are to be compared. The expected means are 20, 25 and 45 for the three age groups respectively. The total sample of 57 subjects achieves 82% power to detect differences among the means versus the alternative of equal means using an F test with a 0.05 significance level.Conclusions: The results of this pilot study support further investigation of the relationship between age and lateral sleep position preference, and particularly the physiological parameters which may underpin the adoption of different sleep positions with increasing age. The described method is appropriate and modifications are suggested to further improve future studies.