Prevalence of CVA at Study Entry
| Age at Entry (yr) . | SS . | SC . | S-β+ . | S-β0 . | Unknown* . | Total . |
|---|---|---|---|---|---|---|
| N | 2,675 | 873 | 203 | 192 | 139 | 4,082 |
| <2 | 0.00 | 0.00 | 0.00 | 4.76 (1) | 0.00 | 0.11 (1) |
| 2-5 | 2.29 (8) | 0.00 | 0.00 | 0.00 | 30.0 (3) | 2.32 (11) |
| 6-9 | 4.93 (14) | 1.02 (1) | 0.00 | 0.00 | 64.7 (11) | 5.79 (26) |
| 10-19 | 5.52 (39) | 1.06 (2) | 1.64 (1) | 0.00 | 48.2 (13) | 5.27 (55) |
| 20-29 | 5.33 (26) | 1.60 (2) | 2.56 (1) | 0.00 | 10.0 (2) | 4.35 (31) |
| 30-39 | 7.22 (14) | 1.32 (1) | 0.00 | 7.69 (1) | 33.3 (2) | 5.84 (18) |
| 40-49 | 8.57 (6) | 0.00 | 16.67 (1) | 33.3 (1) | 0.00 | 7.62 (8) |
| ≥50 | 7.14 (2) | 5.26 (1) | 0.00 | 0.00 | 0.00 | 5.17 (3) |
| Overall | 4.07 (109) | 0.80 (7) | 1.48 (3) | 1.56 (3) | 22.3 (31) | 3.75 (153) |
| Age-adjusted | 4.01 | 0.84 | 1.29 | 2.43 | 27.2 |
| Age at Entry (yr) . | SS . | SC . | S-β+ . | S-β0 . | Unknown* . | Total . |
|---|---|---|---|---|---|---|
| N | 2,675 | 873 | 203 | 192 | 139 | 4,082 |
| <2 | 0.00 | 0.00 | 0.00 | 4.76 (1) | 0.00 | 0.11 (1) |
| 2-5 | 2.29 (8) | 0.00 | 0.00 | 0.00 | 30.0 (3) | 2.32 (11) |
| 6-9 | 4.93 (14) | 1.02 (1) | 0.00 | 0.00 | 64.7 (11) | 5.79 (26) |
| 10-19 | 5.52 (39) | 1.06 (2) | 1.64 (1) | 0.00 | 48.2 (13) | 5.27 (55) |
| 20-29 | 5.33 (26) | 1.60 (2) | 2.56 (1) | 0.00 | 10.0 (2) | 4.35 (31) |
| 30-39 | 7.22 (14) | 1.32 (1) | 0.00 | 7.69 (1) | 33.3 (2) | 5.84 (18) |
| 40-49 | 8.57 (6) | 0.00 | 16.67 (1) | 33.3 (1) | 0.00 | 7.62 (8) |
| ≥50 | 7.14 (2) | 5.26 (1) | 0.00 | 0.00 | 0.00 | 5.17 (3) |
| Overall | 4.07 (109) | 0.80 (7) | 1.48 (3) | 1.56 (3) | 22.3 (31) | 3.75 (153) |
| Age-adjusted | 4.01 | 0.84 | 1.29 | 2.43 | 27.2 |
The percentage of patients with CVA history, by age group and hemoglobin genotype, is shown. Numbers of patients with CVA before entry are in parentheses.
Patients whose Hb genotype was not confirmed because of transfusion therapy. When these patients are combined with the SS group, the modified prevalence estimate is 4.98% (age-adjusted rate, 4.96%) for the SS patients.