Block 1: Epidemiology
EPI3-5: FOUR MEASURES OF EFFECT: THE INCIDENCE PROPORTION RATIO

The Incidence Proportion, IP, is defined as:

The Incidence Proportion Ratio is given by:

Example:

A followup study of a cohort of 10000 workers in a high exposure zone for the incidence of hearing loss over 10 years showed that a further 1813 workers developed noise induced hearing loss. Another cohort of 10 000 workers in a low noise exposure zone produced 952 workers with hearing loss over the same period. The incidence proportion ratio is




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General Introduction to Occupational Health: Occupational Hygiene, Epidemiology & Biostatistics by Prof Jonny Myers is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.5 South Africa License
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