Maximum (max) and mid-P confidence intervals and p values for the standardized mortality and incidence ratios

Pandurang M. Kulkarni, Ram C. Tripathi, Joel E. Michalek

Research output: Contribution to journalArticle

13 Scopus citations


The authors present algorithms to compute the confidence interval for a Poisson parameter (λ) and the p value for testing the hypothesis that λ is equal to a constant, which can be used to make inferences about the standardized mortality ratio and the standardized incidence ratio. The p value and confidence interval always agree, despite the discrete nature of the Poisson distribution. The authors also give simple equations to compute numeric approximations of the confidence limits that do not require the use of any probability distributions. An example based on data arising from a study of cancer incidence is given.

Original languageEnglish (US)
Pages (from-to)83-86
Number of pages4
JournalAmerican journal of epidemiology
Issue number1
Publication statusPublished - Jan 1 1998



  • Confidence intervals
  • Poisson distribution
  • Risk
  • Significance tests

ASJC Scopus subject areas

  • Epidemiology

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