Table 2.
Measures of agreement between self-reported weight and weight measured during the first pregnancy trimester among Brazilian women in the Brazilian Maternal and Child Nutrition Consortium (BMCNC) and in the Brazilian Food and Nutritional Surveillance System (SISVAN)
| 30–94 days (up to 13 weeks) | 30–60 days (up to 8 weeks)a | 30–45 days (up to 6 weeks)a | |
|---|---|---|---|
| BMCNC | |||
| Number of individuals | 5563 | 1691 | 502 |
| ICC (95% CI) | 0.952 (0.949–0.954) | 0.959 (0.956–0.963) | 0.961 (0.954–0.967) |
| Lin’s coefficient (95% CI) | 0.952 (0.949–0.954) | 0.959 (0.956–0.963) | 0.961 (0.953–0.967) |
| Kappa coefficient (95% CIb) | 0.867 (0.857–0.875) | 0.888 (0.868–0.903) | 0.897 (0.865–0.923) |
| Mean gestational age in the period (days) | 69 | 49 | 40 |
| SISVAN | |||
| Number of individuals | 393,095 | 173,676 | 63,117 |
| ICC (95% CI) | 0.976 (0.975–0.976) | 0.978 (0.978–0.979 | 0.979 (0.979–0.980) |
| Lin’s coefficient (95% CI) | 0.976 (0.975–0.976) | 0.978 (0.978–0.979 | 0.979 (0.979–0.980) |
| Kappa coefficient (95% CIb) | 0.909 (0.909–0.910) | 0.918 (0.917–0.920) | 0.923 (0.921–0.925) |
| Mean gestational age in the period (days) | 63.3 | 47.9 | 39.8 |
Notes: aCumulative analysis. b500 replications; there is a small difference in the sample size for the calculation of the Kappa coefficient for BMI due to missing data in height, in the BMCNC dataset (n = 5381 for 30–94 days, n = 1617 for 30–60 days, n = 480 for 30–45 days). BMCNC Brazilian Maternal and Child Nutrition Consortium, CI Confidence interval, ICC Intraclass correlation coefficient, SD Standard deviation, SISVAN Brazilian Food and Nutritional Surveillance System