Table 1.
Rate ratios for combined non-fatal myocardial infarction (MI) or death from coronary heart disease (CHD) associated with various factors in patients taking low dose aspirin
| Factor | No (%) of controls (n=5000) | No (%) with non-fatal MI/CHD death (n=1222) | Rate ratio (95% CI) | |
|---|---|---|---|---|
| Unadjusted* | Adjusted† | |||
| Smoking: | ||||
| Never | 2014 (40.3) | 404 (33.1) | 1.00 | 1.00 |
| Current | 724 (14.5) | 259 (21.2) | 1.86 (1.55 to 2.23) | 1.67 (1.38 to 2.03) |
| Former | 2135 (42.7) | 527 (43.1) | 1.28 (1.10 to 1.48) | 1.15 (0.98 to 1.35) |
| Unknown | 127 (2.5) | 32 (2.6) | 1.08 (0.72 to 1.63) | 1.26 (0.82 to 1.91) |
| BMI: | ||||
| 15-19 | 133 (2.7) | 35 (2.9) | 1.16 (0.78 to 1.73) | 1.04 (0.69 to 1.58) |
| 20-24 | 1316 (26.3) | 304 (24.9) | 1.00 | 1.00 |
| 25-29 | 1934 (38.7) | 469 (38.4) | 1.06 (0.90 to 1.24) | 1.10 (0.93 to 1.31) |
| 30-59 | 1119 (22.4) | 284 (23.2) | 1.16 (0.96 to 1.39) | 1.10 (0.91 to 1.34) |
| Unknown | 498 (10.0) | 130 (10.6) | 1.07 (0.85 to 1.35) | 1.13 (0.87 to 1.46) |
| Visits to primary care practitioner‡: | ||||
| <5 | 441 (8.8) | 86 (7.0) | 1.00 | 1.00 |
| 5-9 | 1356 (27.1) | 255 (20.9) | 1.02 (0.78 to 1.33) | 0.98 (0.74 to 1.30) |
| 10-19 | 2147 (42.9) | 518 (42.4) | 1.35 (1.05 to 1.74) | 1.16 (0.89 to 1.53) |
| ≥20 | 1056 (21.1) | 363 (29.7) | 1.96 (1.50 to 2.55) | 1.49 (1.11 to 2.00) |
| Referrals‡: | ||||
| 0-1 | 2391 (47.8) | 472 (38.6) | 1.00 | 1.00 |
| 2-4 | 1476 (29.5) | 379 (31.0) | 1.34 (1.15 to 1.56) | 1.22 (1.04 to 1.44) |
| 5-9 | 812 (16.2) | 249 (20.4) | 1.65 (1.39 to 1.97) | 1.39 (1.15 to 1.68) |
| ≥10 | 321 (6.4) | 122 (10.0) | 2.10 (1.66 to 2.66) | 1.71 (1.32 to 2.20) |
| Admission to hospital‡: | ||||
| 0 | 4133 (82.7) | 834 (68.3) | 1.00 | 1.00 |
| 1-2 | 721 (14.4) | 309 (25.3) | 2.11 (1.81 to 2.46) | 1.76 (1.49 to 2.08) |
| ≥3 | 146 (2.9) | 79 (6.5) | 2.74 (2.06 to 3.65) | 2.06 (1.50 to 2.83) |
| Morbidity at start date§: | ||||
| Myocardial infarction | 1160 (23.2) | 450 (36.8) | 1.95 (1.70 to 2.23) | 1.91 (1.61 to 2.55) |
| Angina | 1790 (35.8) | 491 (40.2) | 1.19 (1.04 to 1.35) | 1.10 (0.93 to 1.30) |
| Unstable angina | 162 (3.2) | 66 (5.4) | 1.69 (1.26 to 2.27) | 1.43 (1.04 to 1.96) |
| Cerebrovascular disease | 1704 (34.1) | 334 (27.3) | 0.72 (0.63 to 0.83) | 1.24 (1.04 to 1.49) |
| COPD | 286 (5.7) | 137 (11.2) | 2.04 (1.65 to 2.54) | 1.56 (1.22 to 1.99) |
| Diabetes | 645 (12.9) | 218 (17.8) | 1.48 (1.25 to 1.75) | 1.49 (1.24 to 1.78) |
| Atrial fibrillation | 294 (5.9) | 73 (6.0) | 0.98 (0.75 to 1.27) | 1.04 (0.78 to 1.41) |
BMI=body mass index; COPD=chronic obstructive pulmonary disease.
*Adjusted for matched variables: sex, age, and calendar year.
†Adjusted for age, sex, calendar year, time to event, smoking, ischaemic heart disease (at start date), cerebrovascular disease (at start date), diabetes (at start date), COPD (at start date), atrial fibrillation (at start date), use of clopidogrel, statins, anticoagulants, nitrates, antihypertensives, oral steroids or non-steroidal anti-inflammatory drugs, and discontinuation of aspirin.
‡In year before index date.
§Reference group: no diagnosis of relevant morbidity.