Reliability and diagnostic validity of a joint vibration analysis device

Background: This observational study was designed to evaluate the reliability and diagnostic validity of Joint Vibration Analysis (JVA) in subjects with bilateral disc displacement with reduction and in subjects with bilateral normal disc position. Methods: The reliability of selecting the traces was assessed by reading the same traces at an interval of 30 days. The reliability of the vibrations provided by the subjects was assessed by obtaining two tracings from each individual at an interval of 30 min. The validity compared the Joint Vibration Analysis parameters against magnetic resonance imaging as the reference standard. The data were analyzed with exploratory factor analysis. Results: The short- term reliability of the Joint Vibration Analysis outcome variables showed excellent results. Implementing factor analysis and a receiver operating characteristic as analytical methods showed that six items of the Joint Vibration Analysis outcome variables could be scaled and normalized to a composite score which presented acceptable levels of sensitivity and specificity with a receiver operating characteristic of 0.8. Conclusion: This study demonstrated that the composite score generated from the Joint Vibration Analysis variables could discriminate between subjects with bilateral normal versus bilateral displaced discs.