|
|
 |
 |
 |
|
|
|||
|
||||
|
||||
Re: risk for down syndromeFrom: Doc Gyneco (jmbr@wanadoo.fr)Wed Dec 4 16:34:06 2002
le 3/12/02 9:32, Patrizia :
> could you please show me how you calculate the sequential risk in detail, BAYES¹ theorem : Risk after test = risk before test * likelihood ratio Likelihood ratio (LR) = risk after test : risk before test 1) LR first trimester = 0,00031133 : 0,00243309 = 0,12795663 2) LR second trimester = 0,00262467 : 0,00243309 = 1,07873938 3) Integrated risk = LR first * LR second * risk before test Integrated risk = 0,12795663 * 1,07873938 * 0,00243309 Integrated risk = 0,00033584 ‰ 1/2978 BUT ++++ I agree with the message of Dave Berck. 1) the rate of Down syndrome decrease ³slightly² from 12 weeks of gestation to 15-18 weeks of gestation 2) more serious : there is a correlation between first trimester HCG level and second trimester HCG level and we have to rule out the first. The ³true² integrated risk will be a few less than the risk we¹ve calculated (but we are far away from the usual threshold).
-- Bien tropicalement, Dr J-M BRIDERON (MD) Gyn-Obs ECHOLIST : liste de diffusion sur l'echographie gyn-obs http://www.gyneweb.fr/echolist.htm
|
|
Return to
|
Mail a New Message to the Forum: ultrasound@obgyn.net Forum Administrator: terry.dubose@obgyn.net Report Technical Problems: webmaster@obgyn.net Last Updated: Mon Nov 2 05:35:37 2009 |
The American Medical Association is no longer designating CME hours for AMA Category II CME credit. However, physicians themselves may self designate learning activities as Category II CME credit hours if they feel it is of sufficient educational merit and meets the formal definitions of continuing medical education. OBGYN.net believes these interaction in this forum meets these criteria. For further information see the AMA web site.