Abstract
BackgroundNo prior studies have examined systematic bias in the musculoskeletal physical examination. The objective of this study was to assess the effects of bias due to prior knowledge of lumbar spine magnetic resonance imaging findings (MRI) on perceived diagnostic accuracy of the physical examination for lumbar radiculopathy.MethodsThis was a cross-sectional comparison of the performance characteristics of the physical examination with blinding to MRI results (the 'independent group') with performance in the situation where the physical examination was not blinded to MRI results (the 'non-independent group'). The reference standard was the final diagnostic impression of nerve root impingement by the examining physician. Subjects were recruited from a hospital-based outpatient specialty spine clinic. All adults age 18 and older presenting with lower extremity radiating pain of duration ≤ 12 weeks were evaluated for participation. 154 consecutively recruited subjects with lumbar disk herniation confirmed by lumbar spine MRI were included in this study. Sensitivities and specificities with 95% confidence intervals were calculated in the independent and non-independent groups for the four components of the radiculopathy examination: 1) provocative testing, 2) motor strength testing, 3) pinprick sensory testing, and 4) deep tendon reflex testing.ResultsThe perceived sensitivity of sensory testing was higher with prior knowledge of MRI results (20% vs. 36%; p = 0.05). Sensitivities and specificities for exam components otherwise showed no statistically significant differences between groups.ConclusionsPrior knowledge of lumbar MRI results may introduce bias into the pinprick sensory testing component of the physical examination for lumbar radiculopathy. No statistically significant effect of bias was seen for other components of the physical examination. The effect of bias due to prior knowledge of lumbar MRI results should be considered when an isolated sensory deficit on examination is used in medical decision-making. Further studies of bias should include surgical clinic populations and other common diagnoses including shoulder, knee and hip pathology.
Highlights
No prior studies have examined systematic bias in the musculoskeletal physical examination
The results of prior imaging are often reviewed by the spine specialist prior to the physical examination; this may occur while the history is being obtained, or while the patient is changing into a gown prior to the physical examination
Given the well-known prevalence of incidental findings on lumbar spine magnetic resonance imaging findings (MRI) [5,6], prior knowledge of lumbar MRI results introduces the potential for systematic bias in the performance of the physical examination
Summary
No prior studies have examined systematic bias in the musculoskeletal physical examination. The objective of this study was to assess the effects of bias due to prior knowledge of lumbar spine magnetic resonance imaging findings (MRI) on perceived diagnostic accuracy of the physical examination for lumbar radiculopathy. Diagnostic tests are of vital importance in clinical decision-making In acknowledgment of this fact, guidelines such as the Standards for Reporting of Diagnostic Accuracy (STARD) have been established to improve the quality of design and reporting in diagnostic accuracy studies [1]. As a consequence of this common practice, the performance of the physical examination in specialty spine care may be influenced by prior knowledge of the results of MR imaging. Since the detection of abnormalities on physical examination may affect the decision to pursue surgery or further diagnostic testing, bias in the physical examination may have substantial implications for the practice of spine care. The effects of prior knowledge of lumbar spine MRI results on the performance of the physical examination have not been previously studied
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
