Approaches for estimating prevalence ratios.
Occup Environ Med 2008 Jul; 65(7):501-506
Recently there has been much interest in estimating the prevalence (risk, proportion or probability) ratio instead of the odds ratio, especially in occupational health studies involving common outcomes (for example, with prevalence rates above 10%). For example, if 80 out of 100 exposed subjects have a particular disease and 50 out of 100 non-exposed subjects have the disease, then the odds ratio (OR) is (80/20)/(50/50) = 4. However, the prevalence ratio (PR) is (80/100)/(50/100) = 1.6. The latter indicates that the exposed subjects are only 1.6 times as likely to have the disease as the non-exposed subjects, and this is the number in which most people would be interested. There is considerable literature on the advantages and disadvantages of OR versus PR. In this article we will review the existing methods and give examples and recommendations on how to estimate the PR.
Statistical-analysis; Mathematical-models; Risk-factors; Analytical-models; Risk-analysis; Safety-monitoring; Safety-research; Health-hazards; Health-sciences; Health-surveys
James A Deddens, National Institute for Occupational Safety and Health, DSHEFS, Mail Stop R15, 4676 Columbia Parkway, Cincinnati, OH 45226
Occupational and Environmental Medicine