Number of diseased subjects recruited in control sample (A); Ratio of upper and lower bound of 95% confidence intervals of prevalence odds (B), in a case-base study of 200 distinct subjects (solid lines), 2000 distinct subjects (dashed lines) and 20000 distinct subjects (dotted lines).

<p>Number of diseased subjects recruited in control sample (A); Ratio of upper and lower bound of 95% confidence intervals of prevalence odds (B), in a case-base study of 200 distinct subjects (solid lines), 2000 distinct subjects (dashed lines) and 20000 distinct subjects (dotted lines).