Table 2.
Characteristics of the study populations
| Mean (S.D.) [N] or n (%) |
||
|---|---|---|
| 1946 cohort | 1958 cohort | |
| Total N with data on hysterectomy | 1790 | 4552 |
| Prevalence of hysterectomy up to and including age (years)a | ||
| 30 | 14 (0.8) | 48 (1.1) |
| 35 | 47 (2.6) | 147 (3.2) |
| 40 | 126 (7.0) | 298 (6.5) |
| 44 | 209 (11.7) | 437 (9.6) |
| 50 | 337 (18.8) | – |
| 55 | 393 (22.0) | – |
| Body mass index (kg/m2) at age (years) | ||
| 15 | 20.7 (3.0) [1336] | – |
| 16 | – | 21.0 (2.9) [3327] |
| 20 | 21.9 (2.9) [1427] | – |
| 23 | – | 22.0 (3.1) [3933] |
| 26 | 22.4 (3.3) [1534] | – |
| 33 | – | 24.4 (4.6) [4067] |
| 36 | 23.6 (4.0) [1560] | – |
| 43 | 25.0 (4.8) [1608] | – |
| 44/45 | – | 27.0 (5.6) [4544] |
| 53 | 27.5 (5.5) [1489] | – |
| Waist circumference (cm) at age (years) | ||
| 43 | 77.9 (11.3) [1608] | – |
| 44/45 | – | 85.5 (12.9) [4515] |
| 53 | 85.9 (12.9) [1499] | – |
| Father's occupational class in childhoodb | ||
| I or II | 431 (25.5) | 1085 (25.1) |
| IIINM | 276 (16.3) | 424 (9.8) |
| IIIM | 546 (32.3) | 1790 (41.4) |
| IV or V | 436 (25.8) | 1026 (23.7) |
| Educational level attained | ||
| University degree or higher | 91 (5.4) | 1141 (28.1) |
| Advanced secondary qualificationsc | 374 (22.3) | 439 (10.8) |
| Ordinary secondary qualificationsd | 420 (25.0) | 1510 (37.2) |
| Below secondary qualifications | 157 (9.4) | 646 (15.9) |
| None | 637 (37.9) | 325 (8.0) |
| Own occupational class in adulthoodb | ||
| I or II | 588 (35.8) | 1613 (37.2) |
| IIINM | 611 (37.2) | 1468 (33.9) |
| IIIM | 120 (7.3) | 322 (7.4) |
| IV or V | 323 (19.7) | 930 (21.5) |
| Age at menarche (years) | ||
| ≤11 | 235 (16.4) | 458 (15.7) |
| 12 | 397 (27.7) | 712 (24.4) |
| 13 | 487 (34.0) | 1018 (34.8) |
| ≥14 | 315 (22.0) | 735 (25.2) |
| Parity (at age 43 years in 1946 cohort and 42 years in 1958 cohort) | ||
| 0 | 197 (12.2) | 713 (17.7) |
| 1 | 209 (12.9) | 650 (16.2) |
| 2 | 714 (44.0) | 1718 (42.7) |
| 3 | 353 (21.8) | 722 (18.0) |
| ≥4 | 149 (9.2) | 220 (5.5) |
| Exercise (at age 36 years in 1946 cohort and 33 years in 1958 cohort) | ||
| None 661 (42.0) | ≤2–3 times per month 1243 (30.2) | |
| 1–4 times per month 380 (24.1) | once a week 939 (22.8) | |
| >4 times per month 533 (33.9) | Two to three times per week 846 (20.5) | |
| 4–7 times per week 1093 (26.5) | ||
| HRT use (at age 53 years in 1946 cohort and 44–45 years in 1958 cohort) | ||
| Never | 652 (43.1) | 3955 (88.6) |
| Ex-user | 303 (20.0) | 178 (4.0) |
| Current user | 557 (36.8) | 331 (7.4) |
a
N and % are cumulative.
b
Registrar general's social classification: I or II professional, managerial or technical; IIINM non-manual; IIIM manual skilled; IV or V partly skilled or unskilled.
c
Generally taken at age 18 years.
d
Generally taken at age 16 years.