TABLE 3.
Tracking of UIC from pregnancy until 18 months post‐partum among women in the LiN study
| UIC tertile | Preg–6 weeks pp (n 915) | 6 weeks to 6 months pp (n 849) | 6–12 months pp (n 733) | 12–18 months pp (n 714) | Preg–18 months pp (n 714) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Decrease | Stable | Increase | Decrease | Stable | Increase | Decrease | Stable | Increase | Decrease | Stable | Increase | Decrease | Stable | Increase | |
| Low | NA | 46.0 | 54.0 | NA | 51.3 | 48.7 | NA | 33.5 | 66.5 | NA | 36.0 | 64.0 | NA | 41.2 | 58.8 |
| Middle | 30.1 | 38.1 | 31.8 | 30.4 | 37.7 | 31.9 | 33.9 | 35.2 | 30.9 | 34.7 | 33.8 | 31.5 | 32.0 | 37.3 | 30.7 |
| High | 53.3 | 46.7 | NA | 51.5 | 48.5 | NA | 62.9 | 37.1 | NA | 63.8 | 36.2 | NA | 56.4 | 43.6 | NA |
| κ w a | 0.240 | 0.308 | 0.0276 | 0.0474 | 0.157 | ||||||||||
Abbreviation: UIC, urinary iodine concentration.
a
Tracking coefficient of Cohen's weighted kappa. A κ w of 0.01–0.20 represents slight agreement, 0.21–0.40 fair agreement, 0.41–0.60 moderate agreement, 0.61–0.80 substantial agreement and 0.81–1.00 almost perfect agreement (Landis & Koch, 1977).