Relative risk (RR) is a measure of the strength of the association or causal link between a risk factor and an outcome. Attributable risk (AR) helps measure the excess risk associated with the risk factor. Population attributable risk (PAR) gives the added risk in relation to the total population. RISK RATIO OR RELATIVE RISK Relative risk is the calculated ratio of incidence rates of a health condition or outcome in two groups of people, those exposed to a factor of interest and those not exposed. It is used to determine if exposure to a specific risk factor is associated with an increase, decrease, or no change in the disease or outcome rate when compared to those without the exposure. Relative risk is a statistical measure of the strength of the association between a risk factor and an outcome.
As discussed above, relative risk helps you determine whether and how strongly a precursor is associated with a particular outcome. Attributable risk helps you determine how much of an outcome may be attributable to a particular risk factor (i.e. an estimate of the excess risk) in a population exposed to that factor. This is a valuable measure, since it provides estimates of the relative impact of the poor outcome that could be achieved if the risk factor were reduced or eliminated. On the other hand, one might want to know the proportion of all cases of an outcome in the total population that could be attributed to the exposure to the risk factor. This is called the population attributable risk and when expressed as a percent, the population attributable risk percent. Calculating the population attributable risk percent allows you to determine what percent of an outcome could possibly be prevented if a risk factor were to be removed from the population.
while attributable risk helps us estimate the excess risk among the exposed that can be attributed to the risk factor, from a public health perspective it is often more useful to re-define the attributable risk in terms of the whole population, and thus to know the proportion of cases in the total population that can be attributed to the risk factor. For this calculation, we use the FHOP Planning Guide160
population attributable risk (PAR). Population attributable risk depends not only on the excess risk imposed by the exposure, but also on the share of the total population that is exposed. Two formulas can be used to calculate the PAR:
0 Comments