| n | Number of cases |
| nNDSCR | Number of cases who appear as registered live birth diagnoses in NDSCR |
| nHES | Number of cases who appear as in the HES birth cohort and have an associted “Q90” diagnosis code for Down’s syndrome recorded at any time in HES. |
| nij | Number of cases, with presence in NDSCR (i) and HES (j) indicated by 1 (present) or 0 (absent), such that n00 indicates the number of unrecorded cases. |
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.