Table 4.

Validation of the menstrual status definition according to questionnaire information

	Classification according to plasma E2 and FSH levels
	Post-	Pre-	Total
Classification according to two-page questionnaire
Post-	240	27	267
Pre-	20	72	92
Total	260	99	359
Sensitivity: 240/260 = 92% (95% CI 89–96%)
Specificity: 72/99 = 73% (95% CI 64–82%)
Classification according to eight-page questionnaire
Post-	229	11	240
Pre-	29	86	115
Unknown	2	2	4
Total	260	99	359
Sensitivity: 229/260 = 88% (95% CI 84–92%)
Specificity: 86/99 = 87% (95% CI 80–94%)