Figure 2.
Global and regional prevalence a of SCD in Africa [22–24], Europe [25–29], India [30–35], the Middle East [36–39], and South America/the Caribbean [40]. a Within each region, the prevalence was estimated using a binomial normal model, which assumed a binomial distribution for the individual studies with a mean value drawn from a normal distribution for a regional/global value. The prevalence for each reference was determined from the log odds. A summary estimate was determined for each region with >2 studies. North America had insufficient data to determine the prevalence of SCD. I2 describes the percentage of variation across studies that was due to heterogeneity rather than chance, scored from 0 to 100%, in which 100% is maximum heterogeneity. BN, binomial normal; CI, confidence interval; SCD, sickle cell disease.
Figure 2.
Global and regional prevalence a of SCD in Africa [22–24], Europe [25–29], India [30–35], the Middle East [36–39], and South America/the Caribbean [40]. a Within each region, the prevalence was estimated using a binomial normal model, which assumed a binomial distribution for the individual studies with a mean value drawn from a normal distribution for a regional/global value. The prevalence for each reference was determined from the log odds. A summary estimate was determined for each region with >2 studies. North America had insufficient data to determine the prevalence of SCD. I2 describes the percentage of variation across studies that was due to heterogeneity rather than chance, scored from 0 to 100%, in which 100% is maximum heterogeneity. BN, binomial normal; CI, confidence interval; SCD, sickle cell disease.
Figure 3.
Global and regional prevalence a of sickle cell trait in Africa [22–24,41], Europe [26,28,42], India [30–35,43–45], the Middle East [36–39,46,47], and South America/the Caribbean [48,49]. a Within each region, the prevalence was estimated using a binomial normal model, which assumed a binomial distribution for the individual studies with a mean value drawn from a normal distribution for a regional/global value. The prevalence for each reference was determined from the log odds. A summary estimate was determined for each region with >2 studies. North America had insufficient data to determine the prevalence of SCD. I2 describes the percentage of variation across studies that was due to heterogeneity rather than chance, scored from 0 to 100%, in which 100% is maximum heterogeneity. BN, binomial normal; CI, confidence interval; SCD, sickle cell disease.
Figure 3.
Global and regional prevalence a of sickle cell trait in Africa [22–24,41], Europe [26,28,42], India [30–35,43–45], the Middle East [36–39,46,47], and South America/the Caribbean [48,49]. a Within each region, the prevalence was estimated using a binomial normal model, which assumed a binomial distribution for the individual studies with a mean value drawn from a normal distribution for a regional/global value. The prevalence for each reference was determined from the log odds. A summary estimate was determined for each region with >2 studies. North America had insufficient data to determine the prevalence of SCD. I2 describes the percentage of variation across studies that was due to heterogeneity rather than chance, scored from 0 to 100%, in which 100% is maximum heterogeneity. BN, binomial normal; CI, confidence interval; SCD, sickle cell disease.
Figure 4.
Global and regional birth prevalence a of SCD in Africa [23,50–59], Europe [60–70], India [71], the Middle East [39,72–75], North America [76–79], and South America/the Caribbean [80–91]. a Within each region, the birth prevalence was estimated using a binomial normal model, which assumed a binomial distribution for the individual studies with a mean value drawn from a normal distribution for a regional/global value. The prevalence for each reference was determined from the log odds. A summary estimate was determined for each region with >2 studies. I2 describes the percentage of variation across studies that was due to heterogeneity rather than chance, scored from 0 to 100%, in which 100% is maximum heterogeneity. BN, binomial normal; CI, confidence interval; SCD, sickle cell disease.
Figure 4.
Global and regional birth prevalence a of SCD in Africa [23,50–59], Europe [60–70], India [71], the Middle East [39,72–75], North America [76–79], and South America/the Caribbean [80–91]. a Within each region, the birth prevalence was estimated using a binomial normal model, which assumed a binomial distribution for the individual studies with a mean value drawn from a normal distribution for a regional/global value. The prevalence for each reference was determined from the log odds. A summary estimate was determined for each region with >2 studies. I2 describes the percentage of variation across studies that was due to heterogeneity rather than chance, scored from 0 to 100%, in which 100% is maximum heterogeneity. BN, binomial normal; CI, confidence interval; SCD, sickle cell disease.
Figure 5.
Global and regional birth prevalence a of sickle cell trait in Africa [23,50–54,57–59], Europe [61,63,65–70,92], India [71], the Middle East [72–75], North America [76,79,93,94], and South America/the Caribbean [80–83,85–91]. a Within each region, the birth prevalence was estimated using a binomial normal model, which assumed a binomial distribution for the individual studies with a mean value drawn from a normal distribution for a regional/global value. The prevalence for each reference was determined from the log odds. A summary estimate was determined for each region with >2 studies. I2 describes the percentage of variation across studies that was due to heterogeneity rather than chance, scored from 0 to 100%, in which 100% is maximum heterogeneity. BN, binomial normal; CI, confidence interval; SCD, sickle cell disease.
Figure 5.
Global and regional birth prevalence a of sickle cell trait in Africa [23,50–54,57–59], Europe [61,63,65–70,92], India [71], the Middle East [72–75], North America [76,79,93,94], and South America/the Caribbean [80–83,85–91]. a Within each region, the birth prevalence was estimated using a binomial normal model, which assumed a binomial distribution for the individual studies with a mean value drawn from a normal distribution for a regional/global value. The prevalence for each reference was determined from the log odds. A summary estimate was determined for each region with >2 studies. I2 describes the percentage of variation across studies that was due to heterogeneity rather than chance, scored from 0 to 100%, in which 100% is maximum heterogeneity. BN, binomial normal; CI, confidence interval; SCD, sickle cell disease.
Table 1.
Quantitative analysis of SCD and SCT for prevalence and birth prevalence.
Table 1.
Quantitative analysis of SCD and SCT for prevalence and birth prevalence.
Prevalence |
---|
| SCD | SCT |
---|
Region | No. of Studies | Total Studied Population | Prevalence per 100,000 [95% CI] | No. of Studies | Total Studied Population | Prevalence per 100,000 [95% CI] |
---|
Global | 19 | 130,420,748 | 117 [55; 249] | 24 | 8,335,442 | 2428 [1209; 4814] |
Africa | 3 | 7274 | 788 [316; 1951] | 4 | 11,523 | 17,690 [14,149; 21,891] |
Europe | 5 | 127,536,172 | 28 [10; 79] | 3 | 5,921,455 | 212 [12; 3503] |
India | 6 | 430,952 | 128 [48; 340] | 9 | 472,154 | 2193 [1090; 4364] |
Middle East | 4 | 1,909,565 | 212 [64; 698] | 6 | 1,914,429 | 2429 [934; 6167] |
North America | – | – | NA | – | – | NA |
South America/ the Caribbean | 1 | 536,785 | NA | 2 | 15,881 | NA |
Birth Prevalence |
| SCD | SCT |
Region | No. of Studies | Total Studied Population | Prevalence per 100,000 [95% CI] | No. of Studies | Total Studied Population | Prevalence per 100,000 [95% CI] |
Global | 44 | 92,209,456 | 191 [120; 303] | 44 | 8,661,141 | 3870 [2598; 5728] |
Africa | 11 | 397,651 | 1321 [1041; 1674] | 9 | 377,422 | 15,502 [12,618; 18,901] |
Europe | 11 | 5,407,689 | 33 [20; 54] | 9 | 558,233 | 535 [362; 792] |
India | 1 | 5467 | NA | 1 | 5467 | NA |
Middle East | 5 | 598,718 | 218 [88; 538] | 4 | 559,778 | 2429 [1129; 5148] |
North America | 4 | 79,048,695 | 54 [25; 117] | 4 | 4,026,924 | 1681 [923; 3043] |
South America/ the Caribbean | 12 | 6,751,236 | 201 [102; 395] | 11 | 3,133,317 | 6196 [4344; 8765] |