Denne har sammenlignet mange forskjellige behandingsformer, både aktive og passive og medikamenter, mot korsryggplager og sett at neste alle følger samme behandlingsrespons kurve.

http://rheumatology.oxfordjournals.org/content/49/12/2346.long

Overall response to treatment in clinical trials, cohorts or clinical practice, is not only influenced by the active or specific components of the treatment, but can also be influenced by various other factors. Some of these factors relate to characteristics of the pain problem (as described above), or to the patients themselves [36] such as their beliefs, expectations and experiences with other illnesses, previous episodes of the illness or with previous use of the current treatment or other treatments [37].

An important finding from our review is the large response to treatment common in all trial arms, active as well as placebo, usual care or waiting list arms. It seems ironic that we clearly have evidence for a large overall improvement in back pain symptoms in all arms of clinical trials, while more and more trials are unable to show clear evidence for the effectiveness of the active treatments.