Compare proportion with a dichtomous outcome between two risk groups using the Chi-squared statistic and Fisher's exact test. Provides exact confidence intervals for the risks.

Instructions: Enter parameters in the green cells. Answers will appear in the blue box below.

CL =

Confidence level (%)

R+D+ =

Exposed; disease or outcome positive

R-D+ =

Unexposed; disease or outcome positive

R+ =

TOTAL Exposed

R- =

TOTAL Unexposed

	D+	D−	Total	Risk	CI
R+
R−
Total
Risk difference
Risk ratio

Chi-squared p-value:

Fisher exact one-sided:

Fisher exact two-sided:

Reference:

Fleiss JL, Levin B, Paik MC. Statistical methods for rates and proportions. 3rd ed. Hoboken, N.J.: J. Wiley; 2003. xxvii, 760 p. Chapter 3, page 50.