Statistics

• Proportion of diseased popylation with positive test results
• TP/(TP + FN)

• SNout
• SPin

If the 95% confidence interval crosses zero for a treatment, then it is NOT significant.

If a 95% confidence interval crosses 1 for a relative risk or odds ratio, then it is NOT significant

• 1/(absolute risk reduction)
• 1/(rate in placebo group minus rate in treatment group)

• The number needed to harm (NNH) is the number of pts who get a drug or intervention for each patient harmed.
• 1/(rate harmed in treatment group - rate in placebo group)

divide the incidence with exposure by the incidence without exposure

Incidence with exposure ÷ incidence without exposure

subtract incidence with exposure from incidence without exposure

Incidence with exposure - Incidence without exposure

TN / TN + FP