Research Conducted at Stanford University
This study, entitled “The Effects of Sleeping Surfaces on Sleep Quality,” was conducted for Select Comfort at the Stanford University Medical Center Sleep Research Center by Dr. Riccardo Stoohs during 1996 and 1997. A comparison of two different types of sleeping surfaces was conducted. The sleeping surfaces involved were Sleep Number® air mattresses and premium innerspring mattresses. The eight study subjects were four male and four female “normal, healthy subjects with no complaints regarding their usual sleeping quality.” One goal of the study was to determine if objectively measurable phenomena during sleep were consistent with self-reported sleep quality ratings, and another goal of the study was to determine the time spent by the subjects in the different stages of sleep, particularly how much time was spent in the deeper and more restorative stages of sleep.
All of the study subjects had been sleeping on innerspring mattresses. The study protocol called for each subject to sleep for one week on an innerspring mattress and one week on a Sleep Number® mattress. All subjects were then monitored in a sleep lab for one night to help determine the sleep quality that they were experiencing. The subjects also rated their own sleep quality using visual analog scales. Statistical comparisons of objective and subjective sleep quality were then made.
The significant results of Dr. Stooh’s research were that, compared to subjects sleeping on a premium innerspring mattress, subjects sleeping on a Sleep Number mattress:
- Fell asleep faster.
- Experienced fewer arousals from sleep.
- Spent less time in the lighter stages of sleep, and more time in the deeper and more restorative stages of sleep.
In addition, the subjective sleep quality reports of the study subjects reflected a significantly higher quality of sleep on the Sleep Number mattress.
Dr. Stoohs concluded that the results of his research “suggest that the [Sleep Number mattress] provides a sounder sleep than traditional innerspring mattresses.” In more detail, Dr. Stoohs found that “the individual sleep quality on the [Sleep Number mattress] is better than on a conventional high-end innerspring mattress and that this subjective report of sleep quality is paralleled by objective sleep parameters indicating a lesser amount of light sleep stages, increased amount of REM sleep, and slow wave sleep.”