National EMSC Data Analysis Resource Center
Groups  Purpose  Conditions or Assumptions  Test  Descriptive Measures (also used to calculate CIs) 
Compare proportion to historical or hypothetical (known) proportion 
N > 30 
Onesample ztest (exact binomial N < 30) 
Proportion, difference from historical proportion 


Compare proportion to historical or hypothetical (known) proportion 

Exact binomial test (onesample) 
Proportion, difference from historical proportion 

Compare proportion(s) to hypothetical (known) proportion(s) 
Allows overall comparison of > 2 categories 
Pearson's goodnessoffit Chisquare 
Proportion(s) relative to historical proportion(s) 
Compare proportions (absolute difference) 
N large (> 30) 
Normal approximation to binomial 
Difference between two proportions 


Compare proportions (absolute difference) 

Exact binomial test (two samples) 
Difference between two proportions 
Compare proportions or test for association 
Expected cell count > 1; most > 5 
Chisquare test 
Odds ratio, row and column percentages, 


Compare proportions and test for association 
Use for empty cells or small cell counts 
Fisher's exact test 
Odds ratio, row and column percentages, 

Compare rates and test for association 
Population denominators available (able to calculate valid rates) 
Chisquare or Fisher's exact test 
Relative risk, row and column percentages 
Compare proportions or test for association 

McNemar's test 
Difference between two proportions (different std dev than unmatched) 

Compare proportions or test for association 

Cochrane Q test 
Difference between pairs of proportions 
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rev. 04Aug2022