confidence intervals of odds ratio in an unmatched case control study. For
example groups of cases and controls studied to assess a treatment or exposure
to a suspected causal factor. This
calculator works off-line. (IE4)
Programme written by DJR Hutchon. Enter data into
the boxes "A","B","C",and "D" or
into boxes "A", "A+B", "C", and "C+D"
Enter titles into blank boxes. Clear all values between entering new sets of
values using the clear button.
You can experiment with the effect of different
values keeping the same totals within each study group. The calculator will
adjust the values to keep the totals unchanged.
This calculator is
for educational use. It is believed accurate but no responsibility for accuracy
of the results is accepted by the author. David J R Hutchon BSc, MB, ChB, FRCOG
Consultant Gynaecologist, Memorial Hospital, Darlington, England.
You are welcome to keep this page and use the calculator off-line. I would
appreciate an E-mail if you find it useful enough to do so. E-mail to me at DJRHutchon@hotmail.co.uk
Reference J Martin Bland and Douglas G Altman Statistics Notes: The odds ratio
This calculator will not calculate correctly with zero in any of the boxes. A different approach is required in these circumstances. One method is to estimate the odds ratio using the null hypothesis.
Odds ratio calculator using null hypothesis approach