My colleagues and I thank Dr Casazza for his critical comments. However, we do not agree with his assertion that it is inappropriate to fit an SROCcurve if the Spearman rank correlation coefficient between sensitivity and 1 − specificity is lower than 0.6. The SROC curve is constructed byregressing the difference of the logits (log odds) on the sum of the logits.The difference of the logits is equivalent to the log of the odds ratio betweena positive test result and disease status. The sum of the logits is a measure of the test threshold. The intercept of the regression model is an odds ratio,and the regression coefficient quantifies the extent to which the odds ratiois dependent on the threshold used.
Kittler H. A Note on Meta-analysis of Diagnostic Test Studies—Reply. Arch Dermatol. 2004;140(3):363-364. doi:10.1001/archderm.140.3.364