Q 26 NBME form 1 section 1 - medsid

[ArchivalUser]

Can anyone explain the biostats RR calculation in the q mentioned?

[ArchivalUser]

Number of cases of BC in childless women 180, total number of childless women in study 1000.
Risk of having BC when you don't have a child 180/1000.

Number of cases of BC in women who has children 120, total number of women who has children in the study is 1500.
Risk of having BC if you have child is 120/1500.


Relative risk for BC of childless women compare to who have children is (180/1000)/(120/1500).

Rest is simple math.. :p

[ArchivalUser]

@shonkhochil

Thank you very much. Clean and simple explanation. Makes sense.

I guess I misread the question and was trying to do risk of BC in women with children over without children.

Thanks again