Purpose: The purpose of this study was to investigate the diagnostic accuracy of a finding of pain during the straight leg raise test for lumbar disc herniation, lumbar radiculopathy, and/or sciatica.
Patients and methods: The systematic review followed the PRISMA guidelines and captured articles that had variable designs, standardized reference standards, described an index test of a pain response, and that reported both sensitivity and specificity for the straight leg raise test. Each article specified that a positive straight leg raise test was one in which the subject felt pain during the administration of the test, and was assessed for quality using the QUADAS tool. Sensitivities and specificities were evaluated along with positive and negative likelihood ratios.
Results: The systematic review and hand search identified 7 articles for inclusion; three of these articles were rated as high quality using QUADAS scores. Sensitivity and specificity varied among the 7 studies with 4 suggesting that a pain response SLR is sensitive whereas 3 suggested it is a specific measure.
Conclusions: Variability in reference standard may partly explain the inconsistencies in the diagnostic accuracy findings. Further, pain that is not specific to lumbar radiculopathy, such as that associated with hamstring tightness, may also lead to false positives for the SLR; and may inflate the sensitivity of the test.