Article Figures & Data
Tables
- Table 1A.
Study participants’ characteristics: case-crossover analysis. All covariates are measured prior to the index date. Values are n (%) or mean ± SD unless otherwise specified.
Characteristics Values Subjects, n 270 Age, yrs 73.5 ± 7.4 Female 151 (55.9) BMI, continuous 26.6 ± 4.8 BMI, categorical Underweight 12 (4.4) Normal 65 (24.1) Overweight 96 (35.6) Obese 46 (17.0) Missing 51 (18.9) Smoking Non-smoker 102 (37.8) Ex-smoker 105 (38.9) Current smoker 56 (20.7) Missing 7 (2.6) Alcohol Non-drinker 68 (25.2) Ex-drinker 11 (4.1) Current drinker 168 (62.2) Missing 23 (8.5) Diabetes 45 (16.7) Dyslipidemia 31 (11.5) Hypertension 145 (53.7) Antihypertensives 179 (66.3) Antiaggregants/anticoagulants 26 (9.6) Glucocorticoids 133 (49.3) Lipid-lowering drugs 68 (25.2) Nitrates 19 (7.0) NSAID 151 (55.9) GP visits 11 ± 17 Hospital visits 1 ± 1 BMI: body mass index (underweight ≤ 18.5, normal weight = 18.5–24.9, overweight = 25–29.9, obese = BMI of 30 or greater); NSAID: nonsteroidal antiinflammatory drugs; GP: general practitioner.
- Table 1B.
Study participants’ characteristics: propensity score–matched cohort study. All covariates are measured prior to the index date. Values are n (%) or mean ± SD unless otherwise specified.
Characteristics ASA Initiators ASA Non-users Subjects, n 918 918 Demographic characteristics Age, yrs 71.5 ± 7.2 71.3 ± 7.2 Female 608 (66.2) 601 (65.5) BMI 26.9 ± 4.9 27.1 ± 4.9 Alcohol Non-drinker 237 (25.8) 227 (24.7) Ex-drinker 38 (4.1) 40 (4.4) Current drinker 643 (70.0) 651 (70.9) Smoking Non-smoker 445 (48.5) 406 (44.2) Ex-smoker 309 (33.7) 322 (35.1) Current smoker 164 (17.9) 190 (20.7) RA duration 6.7 ± 4.8 6.7 ± 4.7 Comorbidities Angina 40 (4.4) 29 (3.2) Atrial fibrillation 73 (8.0) 67 (7.3) Diabetes 128 (13.9) 117 (12.7) Dyslipidemia 119 (13.0) 132 (14.4) Hypertension 489 (53.3) 512 (55.8) Cardiovascular disease drugs Antiaggregants/anticoagulants 41 (4.5) 46 (5.0) Antihypertensive drugs ACE inhibitors 228 (24.8) 261 (28.4) ARB 101 (11.0) 112 (12.2) β-blockers 180 (19.6) 180 (19.6) Calcium channel blockers 222 (24.2) 234 (25.5) Diuretics 359 (39.1) 379 (41.3) Lipid-lowering drugs 239 (26.0) 259 (28.2) Nitrates 39 (4.2) 33 (3.6) Antiinflammatory drugs NSAID 510 (55.6) 520 (56.6) Glucocorticoids 322 (35.1) 311 (33.9) Health service use variables GP visits 9 ± 8 10 ± 11 Hospital visits 1 ± 1 1 ± 1 ASA: aspirin; BMI: body mass index (underweight ≤ 18.5, normal weight = 18.5–24.9, overweight = 25–29.9, obese = BMI of 30 or greater); RA: rheumatoid arthritis; ACE: angiotensin-converting enzyme; ARB: angiotensin receptor blocker; NSAID: nonsteroidal antiinflammatory drugs; GP: general practitioner.
- Table 2.
Frequency of potential time-varying confounders between hazard periods and control periods in the case crossover analysis. Values are n (%) unless otherwise specified.
Variables Case Period Control Period Subjects, n 270 270 Antihypertensives 168 (62.2) 157 (58.1) Antiaggregants/anticoagulants 24 (8.9) 19 (7.0) Glucocorticoids 105 (38.9) 111 (41.1) Lipid-lowering drugs 60 (22.2) 62 (23.0) Nitrates 14 (5.2) 8 (3.0) NSAID 119 (44.1) 113 (41.9) NSAID: nonsteroidal antiinflammatory drugs.
- Table 3.
Study results from both study designs. Association of ASA with cardiovascular events in RA.
Study Design Subjects, n Hazard Period Control Period Crude OR (95% CI; case-crossover)
Crude HR (95% CI; PS-matched analysis)Adjusted OR (95% CI; case-crossover)
Adjusted HR (95% CI; PS-matched analysis)Case-crossover: 7-day exposure 270 ASA users 55 44 2.37 (1.04–5.43) 1.83* (0.71–4.71) Case-crossover: 2002–2012 time period, 7-day exposure 219 ASA users 47 38 2.29 (0.94–5.56) 1.96* (0.69–5.55) Case-crossover: concomitant exposure with index date 270 ASA users 52 42 2.00 (0.94–4.27) 1.52* (0.65–3.59) ASA User ASA Non-user PS-matched cohort 1836 MI cases, n 44 32 Total followup time, PY 3531 3668 Mean followup time, yrs 3.85 4.0 Incidence rate, per 1000 PY 12.46 8.72 1.42 (0.90–2.24) 1.39** (0.87–2.23) ↵* Adjusted for atrial fibrillation, diabetes, dyslipidemia, hypertension, peripheral vascular disease, stroke, NSAID, glucocorticoids, statins, nitrates, antihypertensives, anticoagulants, and antiaggregants.
↵** Adjusted RA duration, age, sex, body mass index, smoking, alcohol, angina, atrial fibrillation, diabetes, dyslipidemia, hypertension, angiotensin-converting enzyme inhibitors, antiaggregants/anticoagulants, angiotensin receptor II blockers, β-blockers, calcium channel blockers, diuretics, glucocorticoids, lipid-lowering drugs, nitrates, NSAID, general practitioner visits, hospitalizations. ASA: aspirin; RA: rheumatoid arthritis; PS: propensity score; PY: patient-years; NSAID: nonsteroidal antiinflammatory drugs.
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