Biostatistics and epidemiology: measuring the risk attributable to an environmental or genetic factor.

Disease frequency is measured through estimating incidence rates or disease risk. Several measures are used for assessing exposure-disease association, with adjusted estimates based on standardization, stratification, or more flexible regression techniques. Several measures are available to assess an exposure impact in terms of disease occurrence at the population level, including the commonly used attributable risk (AR). Adjusted AR estimation relies on stratification or regression techniques. Sequential and partial ARs have been proposed to handle the situation of multiple exposures and circumvent the associated non-additivity problem. Despite remaining issues in properly interpreting AR, AR remains a useful guide to assess prevention strategies.