Evaluation of clinician and machine performance in the assessment of low back pain.

Study Design: A prospective blind study to test and compare the performance of clinicians (evaluators) with that of an automated machine (the Spinoscope) in conducting an examination on randomly designated simulators/dissimulators and honest subjects to assess acute benign low back pain.

Objectives: To test the impact of reported pain and history on the clinical examination and to compare the ability of clinicians and the machine to recognize normal findings in a controlled group of subjects with and without benign low back pain.

Background: The literature raises serious questions regarding the efficacy of the clinical examination for patients with low back pain.

Methods: A "gold standard" (clinical examination by experts in low back pain) was established against which the clinical examination by the evaluators and the machine assessment (incorporating weight-lifting ability) of honest subjects and simulators/dissimulators were compared using the receiver operating characteristic technique. The selection of subjects was performed according to strict inclusion and exclusion criteria.

Results: The evaluators were more accurate with the honest subjects, the machine more accurate with the simulators/dissimulators, and, for the entire population tested, the they were equivalent in accuracy (71% vs. 72% concordance). Results from the machine's expert system and from clinician readers of the machine data compared favorably. The machine's concordance with the gold standard increased with increasing loads lifted by the subject.

Conclusion: By relying primarily on the subject's self-presentation, often to the exclusion of objective findings, the clinician may err in evaluating low back function when the patient does not report his or her true condition. The additional functional analysis provided by the machine offers the clinician objective, pertinent information to complement the findings from the clinical examination.