The clinical significance of immediate symptom responses to manual therapy treatment for neck pain: observational secondary data analysis of a randomized trial.

The objective was to explore aspects of symptom responses to manual therapy treatment for neck pain. An observational secondary data analysis of a randomized trial was conducted. 181 participants seeking care from a physiotherapist or chiropractor for a new episode of neck pain were included. Outcome variables included recovery-time and participant-perceived effect of treatment (GPE) at 3-months. There was a significant reduction of ≥1.4 points (95%CI 1.2-1.5) in pre- and post-treatment pain scores at each occasion of treatment. There was also small but significant increases in pain of ≤0.7 points (95%CI 0.4-1.0) between each treatment session, without regression to the preceding pre-treatment level. The relationships between immediate post-treatment effects and longer-term outcomes were explored using multivariate regression analyses. There was significant univariate association between recovery time and cumulative post-treatment changes in pain from the second, third and fourth (Exp(B) = 1.2) treatment sessions, as well as the presence of post-treatment headache (Exp(B) = 0.7) and other minor adverse symptoms (Exp(B) = 0.6). There was significant univariate association between GPE at 3-months and cumulative pain responses from first (B = 0.2), second (B = 0.3), third (B = 0.3) and fourth (B = 0.4) treatment sessions. The change in pain after session 1 was independently associated with GPE (B = 0.2). There was a consistently significant difference of ≥0.7 points (95%CI 0.43-0.89) in the different methods of reporting pain. Our results showed that manual therapy for neck pain involves a "two-steps forward, one-step back" recovery pattern. Whilst minor adverse events are undesirable, they do not seem to be significantly associated with long-term recovery.