Article

"Mechanical Diagnosis and Therapy" (MDT) (also known as the McKenzie
method), like other interventions for low back pain (LBP), has been found to have
small effects for people with LBP. It is possible that a group of patients
respond best to MDT and have larger effects. Identification of patients who
respond best to MDT compared with other interventions would be an important
finding. The purpose of the study was to investigate whether baseline
characteristics of patients with chronic LBP, already classified as derangement
syndrome, can identify those who respond better to MDT compared with Back School.
METHODS: This study was a secondary analysis of data from a previous trial
comparing MDT with Back School in 148 patients with chronic LBP. Only patients
classified at baseline assessment as being in the directional preference group
(n=140) were included. The effect modifiers tested were: clear centralization
versus directional preference only, baseline pain location, baseline pain
intensity, and age. The primary outcome measures for this study were pain
intensity and disability at the end of treatment (1 month). Treatment effect
modification was evaluated by assessing the group versus predictor interaction
terms from linear regression models. Interactions >/=1.0 for pain and >/=3 for
disability were considered clinically important. RESULTS: Being older met our
criteria for being a potentially important effect modifier; however, the effect
occurred in the opposite direction to our hypothesis. Older people had 1.27
points more benefit in pain reduction from MDT (compared with Back School) than
younger participants after 1 month of treatment. LIMITATIONS: The sample (n=140)
was powered to detect the main effects of treatment but not to detect the
interactions of the potential treatment effect modifiers. CONCLUSIONS: The
results of the study suggest older age may be an important factor that can be
considered as a treatment effect modifier for patients with chronic LBP receiving
MDT. As the main trial was not powered for the investigation of subgroups, the
results of this secondary analysis have to be interpreted cautiously, and
replication is needed.
CI - (c) 2016 American Physical Therapy Association.

Langue : ANGLAIS