Initial response to manual therapy a poor predictor of final outcome
MedWire News: Early responses to manual therapy in patients with mechanical low back pain do not accurately predict longer-term outcomes, US researchers believe.
Rather, they propose that within-session and between-session changes "should be considered as a complimentary [sic] artifact along with other examination findings during clinical decision-making."
Chad Cook (Walsh University, North Canton, Ohio, USA) and team studied 100 individuals who were participating in a randomized controlled trial of thrust and nonthrust manipulation physiotherapy for low back pain.
All of the participants had shown an initial positive response to therapy and, for the present study, were assessed for changes in pain scores between the first and second physiotherapy visit.
Any change was then correlated with long-term outcomes such as pain score at discharge, rate of recovery, and change in disability (as assessed using the Oswestry Disability Index [ODI]).
The cohort included 55 women, the mean age was 48.0 years, 90% were White, and the mean duration of symptoms was 23.9 weeks.
Mean ODI was 27.0 at baseline and 9.7 at discharge, representing a significant improvement; indeed, 74% of participants reported a 50% or greater reduction in ODI between the first and final visits.
Similarly, mean pain score (rated on a visual analog scale of 0 to 10) fell from 5.3 at baseline to 1.5 at discharge, indicating a significant improvement, and 79.5% of all participants said they had recovered.
Further analysis showed that the change in pain score between the first and second visit - ie, the within/between-session change - was signficantly correlated with pain and ODI at discharge but not with perceived recovery.
Importantly, however, the correlations between within/between-session change and clinical outcomes were weak and showed poor specificity. For instance, a short-term change in pain score of 2 points or greater accurately predicted a significant long-term improvement in ODI in just 67% of participants.
Cook et al say their results "lend validity" to the belief that a positive initial patient response supports the usefulness of the treatment in that particular patient. However, an initial positive response does not necessarily predict a good long-term outcome.
They conclude: "The commonly used philosophical construct, of evaluating the patient's comparable sign, and applying treatment to directly affect this movement sign, when applied during manual therapy interventions, may be useful as a complimentary [sic] process during clinical decision making."
By Joanna Lyford