Table 3.
General GMS population † | % | Enzyme inducing AED only (n = 3385) | % | Non‐enzyme inducing AED only (n = 14 140) | % | Both types of AED (n = 1836) | % | |
---|---|---|---|---|---|---|---|---|
Any contraceptive methods† | 128 493 | 37.7%* | 745 | 22.0% | 4834 | 34.2% | 352 | 19.2% |
Second generation | 28 995 | 22.6% | 84 | 11.3% | 771 | 16.0% | 38 | 10.8% |
Third generation | 12 865 | 10.0% | 55 | 7.4% | 504 | 10.4% | 37 | 10.5% |
Fourth generation | 27 888 | 21.7% | 77 | 10.3% | 908 | 18.8% | 38 | 10.8% |
Progestin‐only pill | 17 018 | 13.2% | 216 | 29.0% | 919 | 19.0% | 95 | 27.0% |
Mirena device | 7793 | 6.1% | 126 | 16.9% | 435 | 9.0% | 63 | 17.9% |
Patch/implant | 5628 | 4.4% | 24 | 3.2% | 155 | 3.2% | 9 | 2.6% |
Combination of above | 28 306 | 22.0% | 163 | 21.9% | 1142 | 23.6% | 72 | 20.5% |
With oestrogen content < 50 μg | 82 071 | 97.7% | 263 | 93.6% | 2700 | 97.4% | 131 | 95.6% |
With oestrogen content > 50 μg | 1951 | 2.3% | 18 | 6.4 | 71 | 2.6% | 6 | 4.4% |
excluding AED users; assumed denominator (n = 340 981) for eligible population in December 2013, likely to be an under‐estimate for the number over the whole year.
P < 0.001 comparing any contraceptive in general population vs. enzyme‐inducing AED and vs. non‐enzyme‐inducing AED (chi‐square test); ~ comparison of enzyme‐inducing AED vs. general population for oestrogen content P < 0.001 (Fisher’s exact test).