Abstract
Background Recovery from low back pain (LBP) is multidimensional and requires the use of multiple-response (outcome) measures to fully reflect these many dimensions. Predictive prognostic variables that are present or stable in all or most predictive models that use different outcome measures could be considered “universal” prognostic variables.
Objective The aim of this study was to explore the potential of universal prognostic variables in predictive models for 4 different outcome measures in patients with mechanical LBP.
Design Predictive modeling was performed using data extracted from a randomized controlled trial. Four prognostic models were created using backward stepwise deletion logistic, Poisson, and linear regression.
Methods Data were collected from 16 outpatient physical therapy facilities in 10 states. All 149 patients with LBP were treated with manual therapy and spine strengthening exercises until discharge. Four different measures of response were used: Oswestry Disability Index and Numeric Pain Rating Scale change scores, total visits, and report of rate of recovery.
Results The set of statistically significant predictors was dependent on the definition of response. All regression models were significant. Within both forms of the 4 models, meeting the clinical prediction rule for manipulation at baseline was present in all 4 models, whereas no irritability at baseline and diagnosis of sprains and strains were present in 2 of 4 of the predictive models.
Limitations The primary limitation is that this study evaluated only 4 of the multiple outcome measures that are pertinent for patients with LBP.
Conclusions Meeting the clinical prediction rule was prognostic for all outcome measures and should be considered a universal prognostic predictor. Other predictive variables were dependent on the outcomes measure used in the predictive model.
Footnotes
Dr Cook, Dr Learman, Mr O'Halloran, and Mr Showalter provided concept/idea/research design. All authors provided writing. Dr Learman, Mr O'Halloran, Mr Showalter, and Mr Kabbaz provided data collection. Dr Cook and Dr Goode provided data analysis. Mr Showalter provided project management and institutional liaisons. Dr Learman, Mr O'Halloran, and Mr Kabbaz provided study participants and facilities/equipment. Dr Learman, Mr Showalter, Mr Kabbaz, Dr Goode, and Dr Wright provided consultation (including review of manuscript before submission).
The study was approved by the Walsh University Human Ethics Review Board.
The study was a secondary database analysis of a randomized controlled trial registered at ClinicalTrials.gov: Identifier NCT01438203.
- Received May 24, 2012.
- Accepted August 2, 2012.
