Scientific studies on 'Sleeping Differently'
- Research University Medical Center Groningen (UMCG)
- Research in collaboration with gezondNU under supervision of Drs. Toine de Graaf
Both studies are described below, followed by a discussion of the results.
1. Research University Medical Center Groningen (UMCG)
Researcher: Liesbeth de Vlugt
Regarding: Master's thesis Clinical Psychology, University of Groningen
Supervisors: Dr. G. Dijkstra, Prof Dr. R. Sanderman
Introduction
In 2014, a study was completed on the effects of 'Sleeping Differently'. It was a pilot preparation for a subsequent, larger-scale study. The primary goal was to determine whether the study design is workable, the right information is obtained, and which procedures should be followed. Additionally, the effect of 'sleeping differently' on tension headaches, neck and back complaints, lying comfort, sleep quality, quality of life (QoL), and social participation was investigated.
Sleeping differently
In the study, 'sleeping differently' means sleeping with the help of a body pillow (Mikoala Body Pillow) and a well-adjusted ergonomic pillow (Hi4Pillow). With these pillows, one actually lies differently in bed.
Sleeping on the side with Body Pillow and Hi4 Pillow
Method
Participants suffering from tension headaches were selected via the Dutch Headache Association (NVvHP). A total of 23 participants took part. The study duration was 14 weeks. Questionnaires were administered before the study started and then every 4 weeks.
Results
A) Effect on complaints
Cohen’s d was used in the data analysis: a measure of Effect Size. The main outcomes:
- Both the number of days with headaches and the severity of headaches decreased (small effect).
- Both the number of days with neck stiffness and neck pain, and the severity of these complaints, decreased (small, almost medium, effect).
- Both the number of days with back stiffness and back pain, and the severity of these complaints, decreased (large effect).
- No differences could be demonstrated in terms of lying comfort and sleep quality.
- The extent to which people were hindered by headaches decreased. This effect is medium-sized.
- Quality of life increased, but only to a limited extent.
B) Procedures
- The written questionnaires performed well;
- The administration of telephone questionnaires proved problematic because subjects were often not easily reachable;
- The procedure by mail worked well and no added value was demonstrated from personally visiting the subjects;
- Personally visiting the participants regularly led to organizational and practical problems;
- In case of problems, participants did not or only late contacted the researcher, causing these problems to be resolved later than necessary. This likely did not benefit the results.
From the above, several improvements were formulated, leading to recommendations for the later large-scale research. It is recommended to reconsider and adjust the inclusion and exclusion criteria.
Discussion
The number of participants was limited. Therefore, it was not possible to perform extensive statistical analyses. Hence, Cohen’s Effect Size analysis was chosen. The results are considered reliable but less so than after extensive statistical testing. For follow-up research, it is highly desirable to significantly increase the number of participants, which will increase statistical possibilities and thus the reliability of the results. Also, effects that could not be detected now could then be demonstrated.
Conclusions
Despite the described limitations and the limited number of participants, effects of 'sleeping differently' could be demonstrated. For headache complaints and to a greater extent for neck and back complaints. No added value was demonstrated for personally visiting the participants, and due to organizational problems, it is recommended to conduct the questionnaires via email or internet. With enough participants and the presence of a control group, extensive statistical analysis is then possible, after which reliable conclusions can be drawn about the effects of 'sleeping differently'.
Also read: Article Back - UMCG Research
Research 2. Research in collaboration with gezondNU under the supervision of Drs. Toine de Graaf
Test with pillow and body pillow shows: fewer complaints, more sleep comfort
A test was conducted by the health magazine gezondNU with the help of their readers. It was investigated whether 'sleeping differently' affects complaints and sleep comfort. 89 test subjects participated and they slept for 30 days according to the advice and with the Hi4 pillow and Mikoala Body body pillow from Ligwijzer.
The test showed among other things:
- Using a Mikoala body pillow significantly improved sleep posture
- A good adjustment of the height of the Hi4 pillow has a big impact on preventing complaints
- Both headache, neck pain, and back pain decreased dramatically
- Sleep quality increased significantly and so did the level of waking up rested
If you want to test the Ligwijzer pillows yourself, look at the bottom of this page for a special offer.
The main findings from the test at a glance (click here for the detailed research report):
1. The lying comfort and the sleep quality increased for 60% of the participants.
2. People felt more rested in the morning and woke up less often at night.
The number of days with headache and also the intensity of the headache decreased by over 45%.
4. The number of days and the level of neck pain decreased by 71% and the intensity of the neck pain by 55%.
5. The number of days with back pain decreased by 39% and the level of back pain by 41%.
6. The stiffness in the neck and back also decreased:
7. People sleep less often on their stomach and in the ¾ position and more on their side.
8. The overall experience with the Hi4 pillow and the Mikoala pillow was better than with their own pillow.
For more information about the GezondNu test:
- Article gezondNU March 2012:
"Less neck and headache with pillows" by Toine de Graaf (pdf)
- Article gezondNU August 2011:
"Headache? Wrong sleeping posture" by Toine de Graaf (pdf)
Click here for the detailed research report of the pillow and body pillow test.