Table 1.
Characteristics of women with breast cancer and matched controls one year before index date by database (QResearch and CPRD). Values are percentages (numbers) of participants unless stated otherwise
| Characteristics | QResearch | CPRD | |||||
|---|---|---|---|---|---|---|---|
| Cases | Controls | Cases | Controls | ||||
| Total | 59 999 | 269 902 | 38 612 | 187 596 | |||
| Mean (SD) age (years) | 63.4 (8.3) | 63.6 (8.3) | 63.4 (8.3) | 63.3 (8.3) | |||
| Age group (years): | |||||||
| 50-59 | 35.7 (21 448) | 34.9 (94 327) | 36.1 (13 946) | 36.6 (68 597) | |||
| 60-69 | 37.4 (22 458) | 37.6 (101 481) | 37.7 (14 557) | 37.6 (70 585) | |||
| 70-79 | 26.8 (16 093) | 27.5 (74 094) | 26.2 (10 109) | 25.8 (48 414) | |||
| Mean (SD) years of records | 10.5 (5.5) | 10.4 (5.5) | 15.4 (5.9) | 16.3 (5.6) | |||
| Ethnicity: | |||||||
| Recorded | 69.3 (41 584) | 70.4 (189 903) | 71.3 (27 546) | 65.0 (121 959) | |||
| White or not recorded | 96.1 (57 646) | 95.1 (256 792) | 97.9 (37 789) | 97.7 (183 347) | |||
| Bangladeshi | 0.1 (73) | 0.3 (691) | 0.0 (9) | 0.0 (85) | |||
| Black African | 0.3 (191) | 0.5 (1450) | 0.2 (60) | 0.2 (298) | |||
| Caribbean | 0.7 (439) | 0.9 (2299) | 0.3 (119) | 0.3 (588) | |||
| Chinese | 0.2 (115) | 0.2 (654) | 0.1 (48) | 0.1 (223) | |||
| Indian | 1.0 (581) | 1.1 (3078) | 0.6 (226) | 0.6 (1134) | |||
| Other | 0.7 (424) | 0.8 (2216) | 0.6 (222) | 0.6 (1093) | |||
| Other Asian | 0.5 (281) | 0.5 (1467) | 0.2 (79) | 0.3 (503) | |||
| Pakistani | 0.4 (249) | 0.5 (1255) | 0.2 (60) | 0.2 (325) | |||
| Townsend fifth*: | *) based on linked cases and controls | ||||||
| 1 (most affluent) | 24.7 (14 810) | 24.5 (66 100) | 27.4 (6201) | 27.1 (29 634) | |||
| 2 | 23.7 (14 191) | 23.2 (62 617) | 25.4 (5745) | 25.1 (27 488) | |||
| 3 | 21.1 (12 630) | 21.1 (56 830) | 21.0 (4747) | 20.9 (22 831) | |||
| 4 | 17.5 (10 492) | 18.0 (48 495) | 17.0 (3847) | 17.2 (18 849) | |||
| 5 (most deprived) | 13.1 (7876) | 13.3 (35 860) | 9.7 (2098) | 9.8 (10 702) | |||
| Body mass index: | |||||||
| Recorded | 80.3 (48 190) | 79.5 (214 580) | 90.2 (34 834) | 86.5 (162 297) | |||
| Mean (SD) | 27.5 (5.5) | 27.2 (5.5) | 27.9 (5.7) | 27.6 (5.7) | |||
| 15-24 | 30.0 (17 999) | 31.6 (85 193) | 32.1 (12 405) | 32.7 (61 395) | |||
| 25-29 | 27.8 (16 696) | 27.0 (72 808) | 31.3 (12 082) | 30.2 (56 570) | |||
| ≥30 | 22.5 (13 495) | 21.0 (56 579) | 26.8 (10 347) | 23.6 (44 332) | |||
| Smoking status: | |||||||
| Recorded | 87.4 (52 411) | 86.7 (233 955) | 95.5 (36 890) | 91.8 (172 123) | |||
| Non-smoker | 40.4 (24 241) | 41.2 (111 282) | 58.5 (22 585) | 57.4 (107 617) | |||
| Former smoker | 32.7 (19 611) | 31.6 (85 217) | 22.2 (8589) | 19.6 (36 761) | |||
| Current smoker: | |||||||
| Light (1-9 cigarettes/day) | 7.6 (4549) | 7.5 (20 259) | 5.9 (2284) | 6.1 (11 379) | |||
| Moderate (10-19) | 4.0 (2419) | 4.0 (10 783) | 5.5 (2141) | 5.3 (9921) | |||
| Heavy (≥20) | 2.7 (1591) | 2.4 (6414) | 3.3 (1291) | 3.4 (6445) | |||
| Alcohol consumption: | |||||||
| Recorded | 79.3 (47 566) | 78.3 (211 354) | 87.4 (33735) | 83.8 (157 295) | |||
| None | 18.2 (10 949) | 19.6 (52 896) | 29.5 (11 376) | 29.6 (55 519) | |||
| Former use | 8.7 (5198) | 8.8 (23 638) | 1.8 (712) | 1.6 (2935) | |||
| Current user: | |||||||
| Trivial (<1unit/day) | 30.9 (18 547) | 30.9 (83 301) | 31.9 (12 304) | 31.0 (58 125) | |||
| Light (1-2 units/day) | 11.6 (6949) | 10.8 (29 208) | 16.7 (6434) | 15.0 (28 090) | |||
| Moderate (3-6) | 9.4 (5610) | 7.9 (21 215) | 5.9 (2279) | 5.4 (10 134) | |||
| Heavy (7-9) | 0.3 (206) | 0.3 (718) | 1.1 (416) | 0.9 (1714) | |||
| Very heavy (≥10) | 0.2 (107) | 0.1 (378) | 0.6 (214) | 0.4 (778) | |||
| History of other cancers: | |||||||
| Any cancer | 2.8 (1656) | 2.4 (6570) | 3.6 (1389) | 3.0 (5540) | |||
| Haematological | 0.4 (252) | 0.3 (936) | 0.5 (180) | 0.4 (755) | |||
| Cervical | 0.2 (114) | 0.2 (612) | 0.2 (73) | 0.2 (440) | |||
| Colorectal | 0.5 (287) | 0.4 (1202) | 0.6 (234) | 0.5 (976) | |||
| Lung | 0.1 (77) | 0.1 (258) | 0.1 (35) | 0.1 (256) | |||
| Melanoma | 0.5 (305) | 0.5 (1230) | 0.5 (203) | 0.4 (660) | |||
| Ovarian | 0.2 (103) | 0.1 (375) | 0.3 (110) | 0.2 (436) | |||
| Uterine | 0.2 (101) | 0.2 (434) | 0.3 (130) | 0.3 (481) | |||
| Chronic conditions: | |||||||
| Benign breast disease | 8.6 (5174) | 5.5 (14 787) | 9.3 (3591) | 6.0 (11 186) | |||
| Diabetes | 6.9 (4112) | 6.7 (17 972) | 7.1 (2757) | 6.6 (12 395) | |||
| Mental health disorder | 0.9 (542) | 0.8 (2046) | 0.9 (345) | 0.8 (1521) | |||
| Osteoporosis | 3.3 (1985) | 3.8 (10171) | 4.0 (1558) | 4.5 (8469) | |||
| Other characteristics: | |||||||
| Early menopause | 13.1 (7831) | 14.0 (37 764) | 11.0 (4230) | 11.9 (22 365) | |||
| Late menopause | 3.2 (1948) | 2.8 (7592) | 8.0 (3093) | 7.0 (13 225) | |||
| Menopausal symptoms | 13.2 (7930) | 12.9 (34 803) | 23.9 (9214) | 22.7 (42 579) | |||
| Mammography scans* | 50.3 (30 170) | 49.9 (134 728) | 21.3 (8242) | 20.1 (37 718) | |||
| MRI/CT scans* | 6.7 (4004) | 6.6 (17 850) | 2.6 (1004) | 2.6 (4919) | |||
| Oophorectomy or hysterectomy | 20.7 (12 437) | 21.6 (58 412) | 21.4 (8264) | 21.1 (39 583) | |||
| Family history: | |||||||
| Any cancer | 9.6 (5784) | 7.9 (21 260) | 5.0 (1939) | 3.8 (7127) | |||
| Breast cancer | 4.3 (2598) | 2.8 (7656) | 3.4 (1329) | 2.1 (3901) | |||
| Cervical cancer | 0.0 (22) | 0.0 (112) | 0.0 (19) | 0.0 (51) | |||
| Osteoporosis | 0.9 (513) | 0.8 (2147) | 0.9 (355) | 0.9 (1610) | |||
| Ovarian cancer | 0.2 (93) | 0.1 (364) | 0.2 (73) | 0.2 (286) | |||
| Uterine cancer | 0.1 (45) | 0.1 (172) | 0.0 (7) | 0.0 (29) | |||
| Any use of other drugs before index date: | |||||||
| Aspirin | 15.9 (9533) | 16.3 (43 880) | 16.3 (6276) | 15.9 (29 869) | |||
| Non-steroidal anti-inflammatory drugs | 62.2 (37 305) | 61.5 (166 024) | 65.6 (25 329) | 64.5 (120 920) | |||
| Contraceptive drugs | 10.9 (6554) | 9.4 (25 494) | 17.4 (6735) | 17.7 (33 149) | |||
| Tamoxifen | 0.7 (436) | 0.1 (277) | 1.0 (389) | 0.2 (394) | |||
| Raloxifene | 0.4 (224) | 0.5 (1278) | 0.4 (168) | 0.5 (858) | |||
MRI=magnetic resonance imaging; CT=computed tomography.
*
Based on Hospital Episode Statistics and general practice data for QResearch and on general practice data for Clinical Practice Research Datalink (CPRD).