Fig. 1: Algorithm used to exclude potential non-EC prescriptions for Ovral. Data for 2001 are presented here and were used to validate the algorithm. *ICD-10 codes for which Ovral is prescribed for non-EC indications: 617 (endometriosis), 625 (pain and other symptoms associated with female genital organs), 626 (disorders of menstruation and other abnormal uterine bleeding) and 639 (complication following abortion or ectopic or molar pregnancy). †These quantities are commonly associated with EC use: 4 represents 1 treatment, 5–6 include additional pills in case of vomiting, 8 represents 2 treatments and 21 for immediate and future use.