Table 3.
Numbers, proportions, and odds ratios (95% CI) for composite features in the 3 years before diagnosis/matchinga
| Composite feature | Comparison with population controls | Comparison with symptomatic controls | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cases (N= 366) | Controls (N = 1453) | Cases (N= 261) | Controls (N= 610) | |||||||||
| n | % | n | % | OR | 95% CI | n | % | n | % | OR | 95% CI | |
| Pain during contraception | 40 | 10.9 | 24 | 1.7 | 7.4 | (4.3 to 12.7) | 40 | 16.5 | 38 | 6.2 | 3.0 | (1.9 to 5.0) |
| Pain follow contraception (180) | 17 | 4.6 | 8 | 0.6 | 8.5 | (3.7 to 19.7) | 17 | 7.0 | 17 | 2.8 | 3.1 | (1.5 to 6.4) |
| Pain exclusive contraception | 105 | 28.7 | 55 | 3.8 | 14.2 | (9.1 to 22.0) | 105 | 43.2 | 110 | 18.0 | 4.3 | (2.9 to 6.2) |
| Menstrual during contraception | 38 | 10.4 | 65 | 4.5 | 2.6 | (1.7 to 4.1) | 38 | 15.6 | 87 | 14.3 | 1.1 | (0.7 to 1.8) |
| Menstrual follow contraception (180) | 14 | 3.8 | 8 | 0.6 | 7.0 | (2.9 to 16.7) | 14 | 5.8 | 17 | 2.8 | 2.0 | (1.0 to 4.2) |
| Analgesic during contraception | 51 | 13.9 | 90 | 6.2 | 2.5 | (1.7 to 3.7) | 39 | 16.1 | 59 | 9.7 | 2.0 | (1.3 to 3.1) |
| Analgesic follow contraception (180) | 27 | 7.4 | 26 | 1.8 | 4.5 | (2.5 to 7.8) | 21 | 8.6 | 21 | 3.4 | 2.8 | (1.5 to 5.3) |
| Analgesic exclusive contraception | 116 | 31.7 | 68 | 4.7 | 12.0 | (8.1 to 17.8) | 116 | 47.7 | 132 | 21.6 | 3.9 | (2.7 to 5.6) |
| NSAID during contraception | 56 | 15.3 | 92 | 6.3 | 2.9 | (2.0 to 4.2) | 48 | 19.8 | 68 | 11.2 | 2.0 | (1.3 to 3.0) |
| NSAID follow contraception (90) | 27 | 7.4 | 28 | 1.9 | 4.0 | (2.3 to 6.8) | 21 | 8.6 | 19 | 3.1 | 3.0 | (1.6 to 5.8) |
| Pain proximity menstrual (360) | 61 | 16.7 | 23 | 1.6 | 15.1 | (8.5 to 26.6) | 61 | 25.1 | 34 | 5.6 | 6.5 | (3.9 to 10.6) |
| Analgesic proximity menstrual (90) | 29 | 7.9 | 19 | 1.3 | 6.3 | (3.5 to 11.4) | 29 | 11.9 | 30 | 4.9 | 2.6 | (1.5 to 4.6) |
| Analgesic proximity pain (90) | 45 | 12.3 | 15 | 1.0 | 15.5 | (8.0 to 30.1) | 45 | 18.5 | 20 | 3.3 | 7.1 | (4.0 to 12.5) |
| NSAID proximity pain (90) | 63 | 17.2 | 28 | 1.9 | 10.9 | (6.7 to 17.7) | 63 | 25.9 | 40 | 6.6 | 6.0 | (3.7 to 9.7) |
| Lower GI proximity pain (90) | 48 | 13.1 | 12 | 0.8 | 15.9 | (8.4 to 29.9) | 48 | 19.8 | 24 | 3.9 | 6.1 | (3.6 to 10.6) |
| Lower GI proximity menstrual (90) | 35 | 9.6 | 23 | 1.6 | 6.3 | (3.7 to 10.7) | 35 | 14.4 | 39 | 6.4 | 2.6 | (1.6 to 4.1) |
| Pain separated by >180 days | 36 | 9.8 | 14 | 1.0 | 12.5 | (6.3 to 24.6) | 36 | 14.8 | 14 | 2.3 | 8.5 | (4.3 to 16.9) |
Composite feature names follow the format X relationship Y [N] where relationship is defined as follows:
X during Y; only used where Y = contraception. X = feature and occurs at least once after the onset date and before the expected offset date of at least one contraceptive prescription.
X follow Y (N); N = number of days. Y = discrete time point event. X = feature and occurs between 1 and N days after Y. Where Y = contraception, N days relate to the expected offset date. X proximity Y (N); used where X and Y = discrete time point events and N is a number of days. X occurs between N days before and N days after Y. X exclusive Y; currently only used where Y = contraception: X = feature. X and Y are present but criteria for X during Y are never met. A single prescription of contraception occurring on the same day as a code for dysmenorrhoea would meet X exclusive Y criteria as X during Y requires X after the onset of contraception. X separated by >(N) days; two consecutive occurrences of X separated by more than N days.
CI = confidence interval. GI = gastrointestinal. NSAID = non-steroidal anti-inflammatory drug. OR = odds ratio.