1. Data were extracted from the BORN Information System (BIS) on 1 Feb, 2022, using cytogenetic testing data with results reported up to June 30, 2021. Note that data submission to the BIS is both voluntary and open to updates and amendments. This table represents a snapshot of the BIS on the date of data extraction.
2. The cohort timeline was defined by infant estimated date of delivery (EDD) (01-Sep-2016 to 31-Mar-2021). 
3. S = point estimate suppressed when confidence interval >20%.
4. Ψ = performance data have a confidence interval greater than 20%. These performance metrics were calculated using small cell sizes from the available Multiple Marker Screening and cytogenetic data in the BIS and are subject to change as more data are collected. Please interpret these data with caution.
5. Only singleton pregnancies were included in this analysis.
6. Only pregnancies with a valid MMS result and cytogenetic result were included in this analysis. Outcome data were supplemented using clinical examination data from the BIS for negative results for T21, and 18 when cytogenetic results were missing.
7. "eFTS" includes both "4-marker eFTS" and "5-marker eFTS".
8. The screen-positive cut-off for STS for trisomy 21 changed over the timeline of this analysis from 1/200 before April 2020 to 1/350 after April 2020. A screen positive result is defined by whether the result was positive based on the cut-off value established at the time of screening

Detection rate = the proportion of pregnancies that are flagged as  "screen positive" by this test and the baby really does have the chromosome difference.

False positive rate =  the proportion of pregnancies that this test will flag as "screen positive" but the baby does not really have the chromosome difference.

1. Data were extracted from the BORN Information System (BIS) on 1 Feb, 2022, using cytogenetic testing data with results reported up to June 30, 2021. Note that data submission to the BIS is both voluntary and open to updates and amendments. This table represents a snapshot of the BIS on the date of data extraction.
2. The cohort timeline was defined by infant estimated date of delivery (EDD) (01-Sep-2016 to 31-Mar-2021). 
3. Only singleton pregnancies were included in this analysis.
4. Only pregnancies with a valid NIPT  result and cytogenetic result were included in this analysis. Outcome data were supplemented using clinical examination data from the BIS for negative results for T21, and 18 when cytogenetic results were missing

Detection rate = the proportion of pregnancies that are flagged as  "high risk" by this test and the baby really does have the chromosome difference.

False positive rate =  the proportion of pregnancies that this test will flag as "high risk" but the baby does not really have the chromosome difference.

Positive predictive value  = what proportion of pregnancies with a "high risk" screening result do have the chromosome difference? In other words, how accurate are the "high results"?  A "high risk" result in a high risk population (e.g. screen positive eFTS, ultrasound abnormalities) is more likely to be a true result than a "high risk" screening result in a low risk population.

Negative predictive value   = what proportion pregnancies with a "low risk" screening result truly do not have the chromosome difference?  In other words, how accurate are the "low risk results"?