TABLE 3.

Interitem correlation matrix.^*†

VARIABLE	VARIABLE
	Stiffness or Pain on Awakening	Pain Frequency	Chewing Affects Pain	Movement Affects Pain	Parafunction Affects Pain
Pain Frequency	0.72
Chewing Affects Pain	0.89	0.78
Movement Affects Pain	0.89	0.74	0.92
Parafunction Affects Pain	0.90	0.78	0.96	0.91
Other Activities Affect Pain	0.83	0.65	0.90	0.85	0.90

^*Correlations with “pain frequency” are based on Kendall τ-b rank correlation; all other correlations are tetrachoric with use of a maximum likelihood estimator.

^†Empty cells are redundant with other cells in the matrix that contain the value.