Crude Rate: The number of events or occurrences of disease in a given time period divided by the population at risk for that event or disease over the same time period.

Age-adjusted Rate (Direct Method): A weighted average of the age-specific incidence or mortality rates from the targeted population(s) where the weights are the proportions of persons in the corresponding age groups of a standard population. In this document, the Year 2000 US population is used as the standard population. Calculating an age-adjusted rate allows for comparisons across targeted populations after accounting or "adjusting" for possible differences in the age-distribution of these populations.

County Rank: This number indicates the ranking of Webster County to the other counties in the state. For example, under Heart Disease Mortality Rates, Webster County has a ranking of 87, This means that only 12 other counties in Iowa have a higher heart disease mortality incidence rate than Webster County and 86 counties have a lower rate. In simple terms, a ranking of 1 indicates the best or healthiest rate in Iowa and a ranking of 99 indicates the worst rate of all counties in Iowa. Therefore, the higher the numerical ranking, the higher the rate of incidence in comparison to the rest of the counties in Iowa. A ranking of 49 would indicate that Webster County is at the median compared to all other Iowa counties.