Evaluation of The Diagnostic Value of Physical Examination in Lumbar Intervertebral Disc Herniation by ROC Curve Analysis

Objective To evaluate the value of physical examination in the diagnosis of lumbar disc herniation by receiver operating characteristic （ROC） curve analysis． Methods Retrospectively analyzed 129 cases of low back pain patients intended to diagnosis with lumbar disc herniation in Spine Surgery Clinic from May 15 to 19, 2017. Eligible patients including 80 males and 49 females, aged from 21 to 68 years old, average 48.1. According to the diagnostic criteria （or gold standard） and based on the medical history + signs （physical examination） + imaging tests （MRI, X-ray, CT, etc.） + or special inspection （electromyography） to include or exclude target diagnosis; A score sheet was used to assess the specialist physical examination, a five-levels method was used to evaluate imaging tests （MRI, X-ray, CT, etc.） results, the value of physical examination and imaging tests in the diagnosis of lumbar disc herniation was evaluated by ROC curve analysis. Results All of the 129 patients completed the relevant tests and diagnosis process according to the diagnostic criteria. 80 patients were diagnosed with lumbar intervertebral disc herniation. The area under the ROC curve of physical examination was 0.793, P=0.000, and the Youden index was 0.48, and the score of physical examination ≥38 was the optimal cutoff, with the corresponding sensitivity of 87.5% and specificity of 40.4%. The area under the ROC curve of imaging results was 0.672, P=0.002, and the Youden index was 0.308, and a score ≥3.5 was the optimal cutoff, with the corresponding sensitivity of 60.0% and specificity of 29.2%. The area under the ROC curve of physical examination and the imaging results were statistically significant compared with 0.5. Conclusions In the diagnosis of lumbar disc herniation, physical examination has higher sensitivity and specificity compare to imaging results, with high diagnostic value. MRI and other imaging tests in outpatient service should be reasonable choosed according to the results of the physical examination.