Pre-print: "Variation in False Negative Rate of RT-PCR Based SARS-CoV-2 Tests by Time Since Exposure"
A new analysis of already published swab (NP swab?) PCR test data.
Goal: model & predict PCR detection probability starting d -5 of symptoms #COVID19 https://www.medrxiv.org/content/10.1101/2020.04.07.20051474v1">https://www.medrxiv.org/content/1...
A new analysis of already published swab (NP swab?) PCR test data.
Goal: model & predict PCR detection probability starting d -5 of symptoms #COVID19 https://www.medrxiv.org/content/10.1101/2020.04.07.20051474v1">https://www.medrxiv.org/content/1...
Data was from two previously published studies:
1. https://www.medrxiv.org/content/10.1101/2020.03.06.20031856v1
2.">https://www.medrxiv.org/content/1... https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa344/5812996
Modeling">https://academic.oup.com/cid/advan... assumptions*
- RT-PCR is 100% specific (no false positives)
- Exposure was 5 day before symptoms
*They aren& #39;t claiming or believe it, just setting parameters.
1. https://www.medrxiv.org/content/10.1101/2020.03.06.20031856v1
2.">https://www.medrxiv.org/content/1... https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa344/5812996
Modeling">https://academic.oup.com/cid/advan... assumptions*
- RT-PCR is 100% specific (no false positives)
- Exposure was 5 day before symptoms
*They aren& #39;t claiming or believe it, just setting parameters.
The pre-print is short and I& #39;m just repeating the claims (statistical modeling is not my field).
First, model predicts, on day 1 of EXPOSURE 100% chance of PCR failure.
By day 4 post-exposure, 61% chance of failure "although there is considerable uncertainty in these numbers"
First, model predicts, on day 1 of EXPOSURE 100% chance of PCR failure.
By day 4 post-exposure, 61% chance of failure "although there is considerable uncertainty in these numbers"
Second, prediction of SARS-CoV2 PCR false negative of #COVID19 patients based on time of SYMPTOMS
Median false negative PCR rate of 39% on day of symptoms.
By day 3 of symptoms, decreases to 26%
By day 19 of symptoms, back up to 61% false negative rate.
https://www.medrxiv.org/content/10.1101/2020.04.07.20051474v1">https://www.medrxiv.org/content/1...
Median false negative PCR rate of 39% on day of symptoms.
By day 3 of symptoms, decreases to 26%
By day 19 of symptoms, back up to 61% false negative rate.
https://www.medrxiv.org/content/10.1101/2020.04.07.20051474v1">https://www.medrxiv.org/content/1...
Third, the reverse question is if SARS-CoV-2 PCR is negative, what& #39;s the probability being infected?
Seems like this one figure short paragraph feel insufficient to the gravity of that question. Test predictive value is population dependent.
This probability is in who exactly?
Seems like this one figure short paragraph feel insufficient to the gravity of that question. Test predictive value is population dependent.
This probability is in who exactly?