Table 5.

Contingency table for interleukin 6 as the golden standard

	Endometriosis group	Control group	Total
Interleukin 6 positive	38	4	42
Interleukin 6 negative	38	76	114
Total	76	80	156
Sensitivity	0.500
Specificity	0.950
Positive predictive value*	0.526
Negative predictive value*	0.945

^*Calculated with the Bayesian approximation for case-control studies, assuming a endometriosis prevalence of 10%