Table 2.
Risk of non-fatal myocardial infarction (MI) or death from coronary heart disease (CHD) among recent discontinuers of low dose aspirin
| No (%) of controls (n=5000) | No (%) with non-fatal MI/CHD death (n=1222) | Rate ratio (95% CI) | ||
|---|---|---|---|---|
| Unadjusted* | Adjusted† | |||
| Current users | 3784 (75.7) | 877 (71.8) | 1.00 | 1.00 |
| Recent discontinuers | 357 (7.1) | 108 (8.8) | 1.30 (1.04 to 1.63) | 1.43 (1.12 to 1.84) |
| Duration of treatment: | ||||
| ≤1 year | 302 (6.0) | 92 (7.5) | 1.31 (1.02 to 1.67) | 1.42 (1.08 to 1.85) |
| ≤30 days | 65 (1.3) | 23 (1.9) | 1.51 (0.93 to 2.45) | 1.45 (0.87 to 2.44) |
| 31-365 days | 237 (4.7) | 69 (5.6) | 1.25 (0.95 to 1.66) | 1.41 (1.05 to 1.91) |
| >1 year | 55 (1.1) | 16 (1.3) | 1.26 (0.72 to 2.22) | 1.48 (0.82 to 2.69) |
| Daily dose: | ||||
| ≤75 mg | 333 (6.7) | 98 (8.0) | 1.27 (1.00 to 1.61) | 1.40 (1.08 to 1.81) |
| 75-300 mg | 24 (0.5) | 10 (0.8) | 1.79 (0.85 to 3.77) | 1.94 (0.89 to 4.22) |
| Reason for discontinuation: | ||||
| Lack of adherence | 242 (4.8) | 75 (6.1) | 1.32 (1.01 to 1.73) | 1.54 (1.15 to 2.06) |
| Treatment change | 39 (0.8) | 17 (1.4) | 1.95 (1.09 to 3.46) | 1.94 (1.01 to 3.74) |
| Safety concerns | 49 (1.0) | 12 (1.0) | 1.04 (0.55 to 1.97) | 0.97 (0.50 to 1.91) |
| Use of over the counter aspirin | 27 (0.5) | 4 (0.3) | 0.68 (0.24 to 1.94) | 0.82 (0.28 to 2.38) |
| Stratified by age (years) | ||||
| No aged <65 | 1242 | 286 | — | — |
| Recent discontinuers | 91 (7.3) | 28 (9.8) | 1.37 (0.87 to 2.15) | 1.73 (1.04 to 2.87) |
| No aged 65-74 | 1751 | 393 | — | — |
| Recent discontinuers | 127 (7.3) | 33 (8.4) | 1.23 (0.82 to 1.85) | 1.32 (0.84 to 2.05) |
| No aged ≥75 | 2007 | 543 | — | — |
| Recent discontinuers | 139 (6.9) | 47 (8.7) | 1.32 (0.93 to 1.87) | 1.39 (0.95 to 2.05) |
| Stratified by sex | ||||
| No of men | 3198 | 810 | — | — |
| Recent discontinuers | 225 (7.0) | 68 (8.4) | 1.25 (0.94 to 1.67) | 1.28 (0.94 to 1.76) |
| No of women | 1802 | 412 | — | — |
| Recent discontinuers | 132 (7.3) | 40 (9.7) | 1.38 (0.95 to 2.01) | 1.71 (1.13 to 2.58) |
*Adjusted for matched variables: sex, age, and calendar year.
†Adjusted for age, sex, calendar year, time to event, smoking status, ischaemic heart disease (at start date), cerebrovascular disease (at start date), diabetes (at start date), chronic obstructive pulmonary disease (at start date), and use of clopidogrel, statins, anticoagulants, nitrates, antihypertensives, oral steroids, or non-steroidal anti-inflammatory drugs.