New Study in the Journal of Clinical Sleep Medicine Finds that People Tend to Overestimate their Self-Reported Sleep Times Compared to Measures by a Sleep Test

WESTCHESTER, Ill. – Self-reports of total sleep times, both habitually and on the morning after a polysomnogram (PSG), or a sleep test, tend to be higher than objectively measured sleep times, according to a study published in the October 15 issue of the Journal of Clinical Sleep Medicine (JCSM).

Graciela E. Silva, PhD, of Arizona State University, analyzed a total of 2,113 subjects who were 40 years of age or older. The participants were 53 percent female, 75 percent Caucasian and 38 percent obese. Dr. Silva compared the subjects’ total sleep time and sleep onset latency obtained from unattended home PSGs to sleep times obtained from the Sleep Heart Health Study (SHHS) Sleep Habits Questionnaire, completed before the PSG and the morning after the PSG. The SHHS Sleep Habits Questionnaire contained questions regarding sleep habits, smoking status as well as cardiovascular and respiratory problems.

The results showed that the mean habitual sleep time was 422 minutes, while the mean morning estimated sleep time was 379 minutes and mean PSG total sleep time was 363 minutes. The mean habitual sleep onset latency was 17 minutes, while the mean morning estimated sleep onset latency was 21.8 minutes and mean PSG sleep onset latency was 16.9 minutes.

Models adjusting for related demographic factors showed that the mean habitual sleep time differed significantly from the PSG total sleep time by 61 minutes. The mean morning estimated sleep time differed fom the PSG total sleep time by 18 minutes.

Further, obese and higher educated people reported less sleep time than their counterparts. Similarly, small but significant differences were seen for sleep latency.

“The findings from this study suggest that results from studies subjectively assessing sleep times may not be comparable to those using objective determinations,” said Dr. Silva.

The SHHS is a prospective multicenter cohort study designed to investigate the relationship between sleep disordered breathing and cardiovascular diseases in the United States.

Those who suspect that they might have a sleep disorder are encouraged to see their primary care physician or a sleep medicine specialist.

JCSM is the official publication of the AASM. It contains published papers related to the clinical practice of sleep medicine, including original manuscripts such as clinical trials, clinical reviews, clinical commentary and debate, medical economic/practice perspectives, case series and novel/interesting case reports.

SleepEducation.com, a Web site maintained by the AASM, provides information about various sleep disorders, the forms of treatment available, recent news on the topic of sleep, sleep studies that have been conducted and a listing of sleep facilities.

For a copy of this article, entitled, “Relationship Between Reported and Measured Sleep Times: The Sleep Heart Health Study (SHHS),” or to arrange an interview with an AASM spokesperson regarding this study, please contact Jim Arcuri, public relations coordinator, at (708) 492-0930, ext. 9317, or jarcuri@aasm.org.

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