Background: Clinical prediction rules (CPRs) are tools that classify the specific characteristics of patients who improve outcome from specific treatments. The specific-direction exercises are useful for non-specific low back pain (NSLBP) patients, but the predictors of CPRs are still limit.

Objective: To develop and validate CPRs for predicting improvement of outcome of specific-direction exercise in NSLBP.

Materials and Methods: Participant with NSLBP, aged 18 to 65 years, who showed the characteristic of centralization (CEN) or directional preference (DP) in mechanical diagnosis were recruited. The efficacy of specific-direction exercise compared with standard physical therapy within four weeks was first verified. Improvement of the Numeric Pain Scale (NPS) score by at least two points and improvement of the Thai version of the Modified Oswestry Low Back Pain Disability Questionnaire (Thai ODQ) score by at least 20% to 30% were examined. Then, four clinical predictors including current onset of NSLBP, pain area, pain characteristics, and Fear Avoidance Beliefs Questionnaire (FABQ) score were tested for the ability to predict improved outcomes of specific-direction exercise in development and validation phase of CPRs.

Results: NSLBP onset at less than six weeks and physical ability score of 14 points or less FABQ were significant predictors of the cumulative effect of specific-direction exercise, which increased the probability to improve the Thai ODQ score by 20% from baseline from 44.6% to 89.6%. NSLBP onset at less than six weeks was the only predictor that increased the probability of improving the Thai ODQ score by 30% from baseline from 45.2% to 71.9%.

Conclusion: NSLBP onset at less than six weeks and physical ability score of 14 points or less FABQ were predictors of improved disability outcome within four weeks of specific-direction exercise that were supported by the validation phase of CPRs.

Keywords: Clinical prediction rule, Treatment outcome, Mechanical diagnosis and treatment, Specific-direction exercise, Low back pain, Physical Therapy

Received 16 Aug 2018 | Revised 11 Dec 2018 | Accepted 17 Dec 2018