Table 2

Classification table with sensitivity and specificity obtained by 10-fold cross validation, used to test the decision tree for knee synovitis shown in fig 1

Actual class	Predicted class		Actual total
Actual class	No synovitis	Synovitis	Actual total
Sensitivity = 75.0%, specificity = 45.0%; LR+ 1.36.
No synovitis	225	275	500
Synovitis	25	75	100
Predicted total	250	350	600