Sensitivity and Specificity of Modified Bragard Test in Patients With Lumbosacral Radiculopathy Using Electrodiagnosis as a Reference Standard.

OBJECTIVE

The purpose of this study was to assess the diagnostic accuracy of a modified Bragard test compared with the straight leg raise (SLR) test in patients presenting with electrodiagnostic evidence of L5 and S1 nerve root compression.

METHODS

This was a cross-sectional study conducted on 506 consecutive patients with signs and symptoms consistent with lumbosacral radiculopathy confirmed by electrodiagnostic study. Patients were evaluated from September 2013 to September 2015 in the physical medicine and rehabilitation outpatient clinic of Shahid Faghihi Teaching Hospital, Shiraz, Iran. The SLR test was investigated concomitantly to determine the sensitivity and specificity.

RESULTS

Electrodiagnostic study findings indicated lumbosacral radiculopathy in 312 patients. Of these participants, 198 were positive on SLR testing, and of 114 SLR-negative patients, 79 were positive on Modified Bragard testing. Sensitivity of the Modified Bragard test was 69.3%, and specificity was 67.42%. Positive and negative predictive values were 73.15% and 63.16%, respectively. Positive likelihood ratio was 2.13, and negative likelihood ratio was 0.46. Diagnostic odds ratio was 4.63. In patients with symptom duration of less than 3 weeks, SLR sensitivity and specificity decreased as the Modified Bragard test diagnostic accuracy increased.

CONCLUSIONS

The Modified Bragard test is easy to perform and has an acceptable test performance, which can help to increase the discriminative power of clinical examination in patients with L5 or S1 nerve root compression who exhibit a negative SLR test result, especially in the acute phase of disease.