A comparison of manual therapy and active rehabilitation in the treatment of non specific low back pain with particular reference to a patient's Linton & Hallden psychological screening score: a pilot study

BACKGROUND: Clinical guidelines for the management of back pain frequently recommend 'manual therapy' as a first line intervention, with psychosocial screening and 'active rehabilitation' for those not improving at 6 weeks post onset. The potential for psychosocial factors to predict treatment response and therefore outcome has not been adequately explored. The purpose of this pilot study was to determine the feasibility of a study to compare manual therapy and active rehabilitation outcomes for subjects with sub-acute/chronic back pain, investigate whether any difference in outcome was related to psychosocial factors, and to inform the design of a main study. METHODS: A convenience sample of 39 patients with non-specific low back pain referred to the physiotherapy department of an acute NHS Trust hospital was recruited over a nine month period. Patients completed the Linton and Hallden psychological screening questionnaire (LH) and were allocated to a low LH (105 or below) or high LH (106 or above) scoring group. The low or high LH score was used to sequentially allocate patients to one of two treatment groups – Manual Therapy comprising physiotherapy based on manual means as chosen by the treating therapist or Active Rehabilitation comprising a progressive exercise and education programme – with the first low LH scoring patient being allocated to active rehabilitation and the next to manual therapy and so on. Treatment was administered for eight sessions over a four-week period and outcome measures were taken at baseline and at four weeks. Measures used were the Roland Morris Questionnaire (RMQ), two components of the Short Form McGill (total pain rating index [PRI] and pain intensity via visual analogue scale [VAS]), and the LH. RESULTS: The manual therapy group demonstrated a greater treatment effect compared with active rehabilitation for RMQ (mean difference 3.6, 95% CI 1.1 – 6.2, p = 0.006) and PRI (7.1, 95% CI 2.0 – 12.2, p = 0.007) and marginally significant results for VAS (15, 95% CI -1.1 to 31.2, p = 0.067). A linear model allowing for confounding effects and the interaction between high or low LH scores supported these results. The interaction effect was not significant for any outcome measure but this could be due to an insufficient number of subjects to detect this effect. CONCLUSION: Comparative evaluation of manual therapy and active rehabilitation with reference to LH psychosocial scores is likely to be detectable by the methods used here. However several alterations to the study design are recommended for the main study. A pragmatic trial using a randomisation process with stratification on the LH score and priori power analysis to determine sample size are suggested for the main study.