title: Interval estimation for the difference between independent proportions: comparison of eleven methods.
abstract: Several existing unconditional methods for setting confidence intervals for the difference between binomial proportions are evaluated. Computationally simpler methods are prone to a variety of aberrations and poor coverage properties. The closely interrelated methods of Mee and Miettinen and Nurminen perform well but require a computer program. Two new approaches which also avoid aberrations are developed and evaluated. A tail area profile likelihood based method produces the best coverage properties, but is difficult to calculate for large denominators. A method combining Wilson score intervals for the two proportions to be compared also performs well, and is readily implemented irrespective of sample size.
authors.affiliation: University of Wales College of Medicine, Heath Park, Cardiff, U.K.
authors.forename: R G
authors.initials: RG
authors.lastname: Newcombe
mesh_terms: D016010:Binomial Distribution; D016001:Confidence Intervals; D005069:Evaluation Studies as Topic; D016013:Likelihood Functions; D016014:Linear Models; D011336:Probability