Accuracy of physical therapists' prognosis of low back pain from the clinical examination: a prospective cohort study

Abstract

Objectives:

To investigate, in patients with chronic or recurrent low back pain (LBP), the predictive validity of history items, demographic variables, outcome measure questionnaire scores, clinical examination items, and physical therapists’ (PTs’) summative estimation of prognosis on a four-point scale. Little is known about the ability of PTs to predict functional outcomes for patients with LBP.

Methods:

This was a multi-centre prospective cohort study of 138 patients with LBP. We used backward stepwise linear regression modelling to estimate the predictive validity of the baseline variables. The endpoint outcome measure was the 18-item Roland–Morris Disability Questionnaire (RM18) at 1 year.

Results:

Of 138 patients with LBP recruited, 89 (64%) completed follow-up at one year. Univariate analysis indicated that PTs’ opinion of prognosis (P = 0·01) and eleven other baseline variables were significantly associated with RM18 at 12 months. In the final multivariate model PTs’ opinion of prognosis (P = 0·022; beta = 0·73, CI 0·55, 0·95), an abnormality detected by passive physiological flexion testing (P = 0·043, beta = 1·61, CI 1·02, 2·57), heavy work (P = 0·069, beta = 0·80, CI 0·62, 1·01), and age (P = 0·079, beta = 1·01 CI 0·99, 1·04) were independent prognostic factors for RM18 outcome, explaining 24% of the variance in the model.

Conclusions:

Musculoskeletal PTs’ summative clinical impression regarding prognosis, following a clinical examination, provides a valid predictive estimation of functional outcome at 1 year in patients with chronic or recurrent LBP.

Keywords:

• Patient examination
• Physical therapist assessment
• Prognosis
• Low back pain
• Spinal segmental mobility

Acknowledgements

The authors gratefully acknowledge the physiotherapists involved in collection of the data used in this study. At the time of data analysis and first reporting, E-MK was a postgraduate student at the University of Otago, School of Physiotherapy: she conducted data analysis and wrote the first draft. JHA recruited the participants, collated and cleaned the data, and revised drafts of this manuscript for publication. This research was funded in part by a University of Otago Research Grant and the New Zealand Society of Physiotherapists Scholarship Trust. Dr Abbott is supported in part by a Sir Charles Hercus Health Research Fellowship from the Health Research Council of New Zealand.