| Family identity was maintained so that sibship was not confounded with any of the other assignments, but was not otherwise considered in statistical analyses. |
| However, it considers only sibship means and does not account for biological relationships between subjects within families. |
| The first is the percentage of each sibship that is female, given that women generally do a disproportionate share of maintaining kinship ties. |
| This phenomenon can be explained in part by the underlying genetic basis of these diseases but this does not account for one sister in a sibship developing pernicious anemia while another develops Hashimoto's thyroiditis. |
| Multiple births are designated by joining the individual symbols to the same point on the sibship line. |
| Potential confounding by parental educational status, parental smoking, sibship size, and housing style, and interactions with site of residence, were also explored. |
