Originally published on SleepSpace.
Abstract
A sleep study was conducted to examine whether bed sheets can improve sleep quality. We partnered with ettitude, a fabric innovation company, to compare ettitude’s proprietary CleanBamboo® sheets to conventional cotton sheets. 32 participants were recruited in a three-week study where sleep was measured for one week in a baseline condition where participants used their original sheets. This was followed by randomly assigning the participant to either a week of ettitude’s CleanBamboo sheets followed by a week of standard cotton sheets, or a week of standard cotton sheets followed by a week of ettitude sheets, randomly counterbalanced. We measured sleep using validated surveys of sleepiness and perceived sleep quality, along with objective measures of sleep from the SleepSpace sleep tracking app. We found that 93.75% of people preferred ettitude sheets to leading competitor sheets and that ettitude sheets improved sleep efficiency by 1.5%, which equates to 7.2 more minutes of sleep per night, or 43 extra hours of sleep a year. This supports the hypothesis that the cooling and comforting feel of ettitude’s CleanBamboo fabric can play a role in improving the public epidemic of poor sleep health.
Introduction
In sleep science, we often take a multi-modal approach to sleep improvement. For example, cognitive behavioral therapy for insomnia generally consists of 5 modules: sleep hygiene, stimulus control, relaxation, cognitive training, and sleep restriction. Your sleep environment may be an additional module that contributes to your sleep health. There is likely an optimal sound, temperature, lighting, and bedding that contributes to a healthier night of sleep. When you sleep, you are constantly making contact with your bedding, which may mean that it plays a significant role in sleep quality. To explore the question of whether the type of bedding impacts your sleep quality, we teamed up with ettitude to test their proprietary CleanBamboo sheets and developed an experiment to determine if CleanBamboo is better than cotton when it comes to your sleep quality.
Study Design
We recruited participants for the study via an email campaign targeted at SleepSpace users. Participants qualified based on if they owned an iPhone, were not shift workers, will not travel in the next month, and did not have young children. 98 participants completed the onboarding survey and consented if they qualified. To be included in the analysis, participants had to complete a sleep diary every day for at least six days in a seven-day period at baseline. Participants were sent two sets of bedding, a set of light blue ettitude CleanBamboo bedding that included sheets and pillowcases, and a set of white competitor bedding made of cotton. The SleepSpace Smart Bed integrates with software available on Android and iPhone and it was also sent to the participant in order to measure sleep without having to touch the sleeper, known as "nearable" sleep sensing technology. The SleepSpace software also connects to various other wearable devices, like Oura Ring, Apple Watch, and Whoop, and delivered custom feedback to the user regarding what sheets to use and when. SleepSpace was used to integrate with various wearables and sleep sensors in the phone to further validate the sleep improvement intervention.
32 participants (mean age = 45) completed the three-week study, based on participation criteria of completing survey assessments of sleep and alertness at four separate time points across the four-week study (see Figure 2). At each of the time-points participants completed a five to 10-minute questionnaire on their perceptions of their original sheets, ettitude’s CleanBamboo sheets, and competitor cotton sheets. The survey included validated assessments of perceived sleep quality (PROMIS) and next-day energy levels (Epworth).
Figure 1. The four time points that assessments were given regarding the last week of sleep. This occurred from left to right: a) Consent / intake, b) Baseline week, after they track for 6-7 days on the sleep diary, c) After the first week of trying the new sheets, d) After the second week, the other set of sheets are randomly tried.[/caption]
Results
The four time points that assessments were given regarding the last week of sleep. This occurred from left to right: a) Consent/intake, b) Baseline week, after they track for six-seven days on the sleep diary, c) After the first week of trying the new sheets, d) After the second week, the other set of sheets are randomly tried.
Figure 2: NPS score for the blue ettitude bamboo sheets
But did ettitude sheets improve people’s sleep quality? To answer this question, we measured people’s perceived sleep quality that they evaluated for the past week of their sleep using the PROMIS survey. We found that people said that their sleep quality improved by more than 10% after trying the ettitude sheets compared to their original sheets (p < .05). This is a clinically significant improvement in perceived sleep quality! Moreover, people said that their alertness during the day improved by more than 25% after sleeping on ettitude sheets compared to their original sheets (p < .05). This suggests that ettitude sheets could significantly improve perceived sleep and alertness the next day—an important finding supporting the importance of sleeping on comfortable bedding.
An even better measure of whether ettitude’s CleanBamboo sheets can improve sleep is the consensus sleep diary that participants were instructed to complete every day that they were participating in the study. In further corroboration of the benefits of ettitude sheets, participants rated their sleep quality as improved on the daily sleep diary with their ettitude sheets compared to their original sheets (p = .07). While many of the other findings were in the right direction, but not significant, perhaps the strongest evidence for the benefits of ettitude sheets was the finding that ettitude sheets improved sleep efficiency by 1.5% compared to their original sheets, which equates to 7.2 more minutes of sleep per night and 43 extra hours of sleep a year (p < .05).
Figure 4. Perceived sleep quality on the consensus sleep diary where the blue ettitude sheets have a significantly better sleep quality associated with them than baseline and the trend is also better for the blue ettitude sheets compared to the competitor sheets.
Conclusion
In a third-party validation study of ettitude sheets, we found that CleanBamboo® sheets were much preferred by sleepers and that CleanBamboo could play an important role in improving sleep quality. Sleep improved across various measures when participants changed from their original sheets to ettitude sheets, with evidence showing that ettitude sheets could save about 43 extra hours of sleep every year you use them. That adds up to a big difference over your lifetime.
Written by Dan Gartenberg PhD
