Table 2.

Unadjusted conditional odds ratios by source of information on oral contraceptive use in women who suffered myocardial infarction (cases) and control women

Progestagen group	No (%) of cases (n=448*)	No (%) of controls (n=1728*)	Unadjusted odds ratios by interview data (95% CI)	Unadjusted odds ratios by GP record data (95% CI)	Unadjusted odds ratios by data combined (95% CI)†
No oral contraception	386 (86.7)	1467 (85.0)	1.00	1.00	1.00
2nd and 3rd generation	40 (9.2)	180 (10.7)	0.79 (0.53 to 1.16)	0.75 (0.50 to 1.11)	0.78 (0.52 to 1.18)
2nd generation	20 (4.5)	119 (7.1)	0.58 (0.35 to 0.98)	0.78 (0.47 to 1.29)	0.73 (0.43 to 1.25)
Norethisterone	2 (0.4)	14 (0.8)	0.49 (0.11 to 2.23)	1.53 (0.39 to 5.97)	1.25 (0.25 to 6.19)
Levonorgestrel	18 (4.0)	105 (6.1)	0.59 (0.34 to 1.03)	0.72 (0.42 to 1.23)	0.69 (0.39 to 1.22)
3rd generation	20 (4.5)	61 (3.5)	1.20 (0.7. to 2.06)	0.71 (0.40 to 1.24)	0.85 (0.48 to 1.51)
Gestodene	11 (2.5)	24 (1.4)	1.72 (0.82 to 3.62)	1.10 (0.51 to 2.35)	1.33 (0.61 to 2.89)
Desogestrel	9 (2.0)	37 (2.1)	0.86 (0.41 to 1.84)	0.48 (0.22 to 1.09)	0.58 (0.25 to 1.31)
Progestagen only	9 (2.0)	49 (2.8)	0.69 (0.34 to 1.43)	0.80 (0.44 to 1.43)	0.80 (0.41 to 1.55)

^*No information on oral contraceptive use obtained from three cases and two controls. There were 10 index women and 30 controls taking other oral contraceptives: type unknown, norgestimate, high dose oestrogen (50 mg mestranol), or cyproterone (interview data). 

^†With interview data when disagreement on current exposure or not, GP record data when disagreement on type of oral contraceptive.