27 dropped out due to poor response — no better than the bottom 10% of responders who competed the study. They were treated as non-responders in the analysis.
There were no significant differences between the waterbed and foam mattress.
There was a minor tendency for patients in the waterbed group to become better, as judged by improvement in lower back pain.
Most of the patients who slept in the waterbed or foam mattress became slightly better, whereas the opposite was the case in the hard-mattress group.
The bottom line?
The authors concluded, “Body-conforming soft mattresses seem to have advantage over hard mattresses.”
“It seems obvious that the more difficult it is to turn from side to side, which is especially the case in a waterbed,” state the authors, “the more seldom it will be done during the sleep. But actually, the more even the pressure distribution, the less are such turns needed.”
Overall, “a waterbed and a body-contour foam mattress generally influenced back symptoms, function, and sleep more positively than a hard mattress, but the differences were small.”
John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at www.Vicus.com, a complementary and alternative medicine website.