Table 2.
Comparisons of hemoglobin concentration measurements among Women, Infants, and Children (WIC) participants in three previous studies, by sampling and analytic method for data collected between 2002 and 2003.
| Kansas City, n = 413 | St. Louis, n = 213 | Cleveland, n = 397 | ||||||
|---|---|---|---|---|---|---|---|---|
| Sampling Method: | Capillary | Venous | Venous | Capillary | Venous | Capillary | Venous | Venous |
| Analytic Method: | HemoCue | HemoCue | Coulter | HemoCue | Coulter | HemoCue | HemoCue | Coulter |
| Mean, g/dL | 12.5 (10.9, 13.9) | 12.2 (10.7, 13.7) | 11.8 (10.4, 13.1) | 11.6 (9.4, 13.4) | 11.5 (9.6, 13.0) | 12.8 (10.9, 14.6) | 12.4 (10.5, 14.1) | 12.6 (910.7, 14.4) |
| Standard deviation, g/dL | 0.9 | 0.9 | 0.8 | 1.2 | 0.9 | 1.2 | 1.1 | 1.1 |
| Anemic, % | 6.8 (4.6, 9.7) 1 | 8.7 (6.2, 11.9) | 14.4 (11.0, 18.9) | 25.8 (20.1, 32.3) | 24.9 (19.2, 30.7) | 6.3 (3.9, 8.7) | 9.3 (6.5, 12.2) | 6.8 (4.3, 9.3) |
| Mean paired difference 2 (95% limits of agreement), g/dL | 0.69 3 (−0.55, 1.94) | 0.36 (−0.59, 1.31) | Referent | 0.07 (−2.01, 2.15) | Referent | 0.24 (−1.11, 1.60) | −0.20 (−1.27, 0.86) | Referent |
| Spearman correlation coefficient | 0.72 (0.67, 0.76) | 0.89 (0.87, 0.91) | Referent | 0.56 (0.46, 0.64) | Referent | 0.81 (0.77, 0.84) | 0.89 (0.87, 0.91) | Referent |
| Participants for whom the difference between Two methods divided by the means of two methods <5%, 4 % | 38.3 (33.6, 43.1) | 76.3 (71.9, 80.3) | Referent | 52.6 (45.9, 59.3) | Referent | 66.3 (61.4, 70.9) | 86.2 (82.4, 89.4) | Referent |
| Sensitivity, 5 % | 32.8 (21.3, 46.0) | 51.7 (38.2, 65.1) | Referent | 60.4 (44.1, 71.4) | Referent | 66.7 (46.0–83.5) | 92.6 (75.7, 99.1) | Referent |
| Specificity, 6 % | 97.7 (95.6, 99.0) | 97.7 (95.6, 99.0) | Referent | 85.6 (79.2, 90.7) | Referent | 98.1 (96.1, 99.2) | 96.7 (94.4, 98.3) | Referent |
1 95% confidence interval (CI) presented in parentheses, unless otherwise specified; 2 Difference in hemoglobin measured by the method indicated versus the referent (venous coulter); 3 Paired t-test, p < 0.05; 4 Number of participants ((difference between two methods/mean of two methods) < 0.05)/all participants; 5 Number anemic by the indicated method and the referent method divided by number anemic by the referent method; 6 Number not anemic by the indicated method and the referent method divided by number not anemic by the referent method.