Age-specific rates (per 1000 person years) of first PMS records in UK general practice
| Age (years) | N | IR | 95% CI |
|---|---|---|---|
| 12–14 | 1056 | 1.21 | (1.14 to 1.28) |
| 15–19 | 1975 | 1.50 | (1.43 to 1.57) |
| 20–24 | 2475 | 1.80 | (1.73 to 1.87) |
| 25–29 | 5165 | 3.28 | (3.19 to 3.37) |
| 30–34 | 8947 | 5.04 | (4.94 to 5.15) |
| 35–39 | 10 768 | 5.61 | (5.50 to 5.71) |
| 40–44 | 8540 | 4.39 | (4.30 to 4.49) |
| 45–49 | 3808 | 2.07 | (2.00 to 2.13) |
PMS, premenstrual syndrome.