Methods: 74 subjects meeting diagnostic criteria per RDC/TMD were recruited from the RDC/TMD validity study at two centers (UB, UW). For the reliability assessment the test and re-test instruments were completed one week apart. The GSE then conducted a review of the core item responses for assessing the validity of the instrument. Kappa and intra-class correlations (ICC) were used; we deemed a cut-off at 0.80 as the minimum for acceptably strong reliability and validity.
Results: For the reliability assessment the kappa/ICC values for the core pain items were: pain in the last 6 months (0.84), pain chronicity (0.98), and pain pattern (0.78). The respective reliability values for the joint sound and locking items were: clicking (0.49), crepitus (0.69) and locking (0.69). General and oral health indicators were above 0.81. For the validity assessment the kappa/ICC values were: pain in the last 6 months (0.78), pain chronicity (0.88) and pain pattern (0.97). Instrument administration design precluded assessment of validity for joint sounds and locking.
Conclusion: The History questionnaire from the original RDC/TMD is reliable in most of the core pain variables but is not for joint sounds and locking. Regarding the validity of the instrument the core pain items are acceptable.
This research was supported by NIDCR Grant U01-DE 013331.