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Reporting Rates and Ratios 

Reporting Rates and Ratios
Numbers and Percentages

Stephen J. Lurie

and Margaret A. Winker

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date: 19 January 2020

Use the virgule construction for rates when placed in parentheses (eg, 1/2) but never in running text. A colon is used for ratios (eg, 1:2). Rates should use the decimal format when the denominator is understood to be 100; otherwise, the denominator should be specified.Of all individuals exposed, children were affected at a rate of 0.05.   The infant mortality rate was 3 per 10 000 live births. Not: The infant mortality rate was 3/10 000 live births.

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