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Wilson confidence intervals for the two-sample log-odds-ratio in stratified 2 × 2 contingency tables

Journal Article


Abstract


  • Large-sample Wilson-type confidence intervals (CIs) are derived for a parameter of interest in many clinical trials situations: the log-odds-ratio, in a two-sample experiment comparing binomial success proportions, say between cases and controls. The methods cover several scenarios: (i) results embedded in a single 2 × 2 contingency table; (ii) a series of K 2 × 2 tables with common parameter; or (iii) K tables, where the parameter may change across tables under the influence of a covariate. The calculations of the Wilson CI require only simple numerical assistance, and for example are easily carried out using Excel. The main competitor, the exact CI, has two disadvantages: It requires burdensome search algorithms for the multi-table case and results in strong over-coverage associated with long confidence intervals. All the application cases are illustrated through a wellknown example. A simulation study then investigates how the Wilson CI performs among several competing methods. The Wilson interval is shortest, except for very large odds ratios, while maintaining coverage similar to Wald-type intervals. An alternative to the Wald CI is the Agresti-Coull CI, calculated from the Wilson and Wald CIs, which has same length as the Wald CI but improved coverage. Copyright © Taylor & Francis Group, LLC.

Authors


  •   Brown, Barbara (external author)
  •   Suesse, Thomas F.
  •   Yap, Vonbing (external author)

Publication Date


  • 2012

Citation


  • Brown, B., Suesse, T. & Yap, V. (2012). Wilson confidence intervals for the two-sample log-odds-ratio in stratified 2 × 2 contingency tables. Communications in Statistics - Theory and Methods, 41 (18), 3355-3370.

Scopus Eid


  • 2-s2.0-84866085377

Ro Metadata Url


  • http://ro.uow.edu.au/infopapers/2297

Number Of Pages


  • 15

Start Page


  • 3355

End Page


  • 3370

Volume


  • 41

Issue


  • 18

Abstract


  • Large-sample Wilson-type confidence intervals (CIs) are derived for a parameter of interest in many clinical trials situations: the log-odds-ratio, in a two-sample experiment comparing binomial success proportions, say between cases and controls. The methods cover several scenarios: (i) results embedded in a single 2 × 2 contingency table; (ii) a series of K 2 × 2 tables with common parameter; or (iii) K tables, where the parameter may change across tables under the influence of a covariate. The calculations of the Wilson CI require only simple numerical assistance, and for example are easily carried out using Excel. The main competitor, the exact CI, has two disadvantages: It requires burdensome search algorithms for the multi-table case and results in strong over-coverage associated with long confidence intervals. All the application cases are illustrated through a wellknown example. A simulation study then investigates how the Wilson CI performs among several competing methods. The Wilson interval is shortest, except for very large odds ratios, while maintaining coverage similar to Wald-type intervals. An alternative to the Wald CI is the Agresti-Coull CI, calculated from the Wilson and Wald CIs, which has same length as the Wald CI but improved coverage. Copyright © Taylor & Francis Group, LLC.

Authors


  •   Brown, Barbara (external author)
  •   Suesse, Thomas F.
  •   Yap, Vonbing (external author)

Publication Date


  • 2012

Citation


  • Brown, B., Suesse, T. & Yap, V. (2012). Wilson confidence intervals for the two-sample log-odds-ratio in stratified 2 × 2 contingency tables. Communications in Statistics - Theory and Methods, 41 (18), 3355-3370.

Scopus Eid


  • 2-s2.0-84866085377

Ro Metadata Url


  • http://ro.uow.edu.au/infopapers/2297

Number Of Pages


  • 15

Start Page


  • 3355

End Page


  • 3370

Volume


  • 41

Issue


  • 18