Table 3.
Incidence rate, relative hazard (95% confidence intervals) and population attributable fraction for atrial fibrillation by race and gender in the Atherosclerosis Risk in Communities (ARIC) study, 1987-2007
| Risk Profile | No. at Risk |
No. of incident AF |
Incidence Rate* |
RH (95% CI) † | PAF % | 95% CI |
|---|---|---|---|---|---|---|
| Total | ||||||
| Optimal RF | 794 | 31 | 2.19 | 0.33 (0.23-0.47) | 0.00 | - |
| Borderline RF only | 4064 | 288 | 3.68 | 0.50 (0.44-0.57) | 6.53 | 1.28 to 11.3 |
| Elevated RF | 9740 | 1201 | 6.59 | 1 [Ref] | 50.0 | 37.5 to 58.5 |
| White Female | ||||||
| Optimal RF | 578 | 21 | 2.02 | 0.33 (0.21-0.52) | 0.00 | - |
| Borderline RF only | 1704 | 89 | 2.68 | 0.45 (0.36-0.56) | 4.29 | −2.73 to 10.1 |
| Elevated RF | 3506 | 415 | 6.04 | 1 [Ref] | 50.0 | 34.4 to 61.1 |
| White Male | ||||||
| Optimal RF | 140 | 10 | 3.95 | 0.40 (0.21-0.75) | 0.00 | - |
| Borderline RF only | 1789 | 179 | 5.17 | 0.55 (0.46-0.65) | 5.85 | −7.40 to 16.8 |
| Elevated RF | 3216 | 538 | 9.07 | 1 [Ref] | 38.2 | 12.7 to 57.5 |
| African-American | ||||||
| Female** | ||||||
| Optimal | 53 | 0 | 0.00 | --- | 0.00 | - |
| Borderline RF | 324 | 9 | 1.69 | 0.42 (0.21-0.83) | 1.57 | −0.72 to 4.50 |
| Elevated RF | 1889 | 141 | 4.10 | 1 [Ref] | 59.5 | 44.2 to 73.5 |
| African-American Male‡ | ||||||
| Optimal | 23 | 0 | 0.00 | --- | 0.00 | - |
| Borderline RF | 247 | 11 | 2.63 | 0.41 (0.22-0.76) | 2.63 | −2.07 to 7.47 |
| Elevated RF | 1129 | 107 | 6.04 | 1 [Ref] | 49.4 | 21.9 to 73.3 |
*
Indicates the incidence rate of AF per 1000 person-years adjusted for age (mean age=54.2 years).
†
Adjusted for age, study site, education, income and height.
‡
African-American females and males did not have any incident cases of AF in the optimal group, so optimal and borderline were combined and PAF from the whole population was applied to obtain the PAF. PAF = population attributable fraction; RH = relative hazard; CI = 95% confidence intervals; RF = risk factors.