• Total number of charts: 3,355
• Charts that showed actual (expert-evaluated) ovulation: 3,037
• Charts with anovulation: 318 Charts without calculated OD: 515
• Charts with both actual and calculated ovulation: 2,662
• Charts with calculated ovulation that actually showed ovulation: 2,662/2,840 (94% positive predictive value)
• Charts with ovulation and which were calculated: 2,662/3,037 (88% specificity).

Interpretation: The BabyMed formula correctly calculated the ovulation day within 2 days of the actual ovulation day in 87% of charts, and in 60% of the charts both the calculated and actual days were the same.