Self-Reported Versus Recorded Sleep Position: An Observational Study

A Peer Reviewed Publication of the College of Allied Health & Nursing at Nova Southeastern University Dedicated to allied health professional practice and education http://ijahsp.nova.edu Vol. 2 No. 1 ISSN 1540-580X Self-Reported versus Recorded Sleep Position: An Observational Study Susan J Gordon, BAppSc Karen A Grimmer, PhD Patricia Trott, M.AppSc Centre for Allied Health Research University of South Australia City East Campus North Terrace, Adelaide Australia CITATION: Gordon, SJ, Grimmer, KA, Trott, P. Self reported versus recorded sleep position: An observational study. The Internet Journal of Allied Health Sciences and Practice. January 2004. Volume 2 Number 1. ABSTRACT Writing is an important tool in the process of learning and communication. Many universities across the United States recognize the importance of implementing writing into respective learning disciplines through a number of approaches. A respiratory therapy program at a large urban university recently assimilated a writing intensive course into their baccalaureate curriculum over a two-year period. A faculty member and a graduate teaching assistant planned as co-instructors various writing assignments that would incorporate writing as an activity to promote critical thinking and learning. The instructors made a dedicated effort to improve professional communication skills through various writing-to-learn strategies and observed the students appreciating an opportunity to be creative. INTRODUCTION Confidence in people’s self-reported sleep position is important in several settings. Allied health professionals rely on patients to supply accurate and reliable information about their ‘usual’ and ‘recent’ sleep positions, and reasons for changes to these, in order to construct appropriate health management strategies.1 For example patients who present to allied health practitioners with nocturnal and or waking musculoskeletal symptoms are often asked about their ‘usual’ and ‘recent’ sleep positions to determine if these could be stressing anatomical structures and contributing to the presenting problem..2 Moreover, a change in sleep position is reported as being beneficial to the health of people who suffer a range of medical conditions such as heartburn, chronic indigestion, 3 asthma or other respiratory illnesses, 4 and sleep apnoea.5 Manufacturers are increasingly producing pillows that are claimed to be specifically designed for side or supine sleepers. Key assumptions are that purchasers are familiar with their ‘usual’ sleeping positions, and that ‘usual’ sleep positions are habitual. People first begin to develop a definite sleep position, at about three months of age, when infants begin to move freely and turn over by themselves, by the age of seven years a definitive sleep position is assumed (6). In adults the most common reported sleep position is the semi-foetal position, with other common positions being full-foetal, prone and supine.6,7,8 Although individuals have a pattern of constancy with regard to sleep position 9 as age increases this pattern changes with increased preference for the side sleep position, decreased preference for the prone sleep position, decreased position shifts and increased amounts of postural immobility 10 lasting between 45 and 110 minutes.11,12 © The Internet Journal of Allied Health Sciences and Practice, 2004 Self-Reported versus Recorded Sleep Position: An Observational Study 2 Adult subjects are reported to change their position of sleep between three and 36 times per night. 6,7,11,13 Reports of position shifts vary considerably between studies due to the sensitivity of the recording or observation technique and the definition of position shift.14 A videotape study undertaken to observe only body position changes in adults reported that participants averaged 13 body position shifts per night.11 Good sleepers change sleep position during the night less often than poor sleepers.7,12,15 Subject self-estimates of body movement frequency during the night are reported to be significantly related to recorded gross body movements.16 Position shifts during the night have been related to stage of sleep,17,18 medication usage, 19,20 level of comfort which may be related to temperature, hardness of the bed surface, 18 soft tissue compression21 uncomfortable pillow,22 unfamiliar surroundings, noise, anxiety and stress,17 medical and musculo-skeletal condition,9, 23, 24, 25, 26 and partner movement.27 This study does not concern itself with issues of sleep laterality but investigates the validity, consistency and reliability of self reported supine, prone and side sleep positions and specifically asks the questions: · · · Do people sleep in the position they report they sleep in? Is there agreement over time with regard to self reports of sleep position? Is there agreement over time between self reported sleep position and recorded sleep position? Ethics approval for this study was gained from the University of South Australia, the Queen Elizabeth Hospital, Woodville, South Australia and complied with the Helsinki Declaration. METHOD Location This study was conducted at the Centre for Sleep Research of the University of South Australia, which is housed at The Queen Elizabeth Hospital, Woodville, South Australia. The sleep laboratories are modern and comfortable with a bed, chair, desk and TV provided in each room. Subjects have access to a lounge room, bathroom and kitchen facilities to allow them to perform their usual bedtime rituals in privacy and comfort. Subjects Subjects were eligible for the study if at the time of the study they were not suffering from any sleep disorder or any current medical or emotional condition which altered their usual sleep behaviours. Twelve eligible male and female volunteers were recruited from individuals known to the Sleep Centre from other studies, and from colleagues of the researchers. Recruitment was in age strata of 18 to 39 years, 40 to 59 years and 60 years and over. All participants were mailed an information sheet two weeks prior to commencement of the study and written informed consent was obtained from each subject at the commencement of the study. Considering the ‘first night’ effect It is general practice in sleep research not to use data collected on the first night of sleep in the sleep laboratory. This is considered to be an adaptation night to take account of the effect of a different sleep environment which may influence usual sleeping patterns. It is known that during a subject’s first night of sleep in a laboratory they have an increased state of vigilance or arousal, which is considered to be a normal stress response to a novel or uncomfortable situation.28.29 The first night effect in normal subjects is characterised by a longer rapid eye movement (REM) sleep latency, increased wakefulness within total sleep time, and decreased sleep efficiency.30 It has been shown that the first night effect is strongl (...truncated)