What is the difference between a “raw number” and a “rate per 10,000 births” as seen in the HBDP Data Book?
Raw numbers have limited value unless they can be compared to other data for statistical purposes. Therefore, to compensate for variations in population, a rate per 10,000 births is used to compensate for these difference in population size. For example, when you look at raw numbers for birth defects by county, it looks like babies born on Oahu have a 75% higher chance of having a birth defect. But when you compensate for the differences in total island population size, you bring all data to the same level to review for differences. A rate is calculated by dividing the numerator (# of birth defects on a specific island) by the denominator (total number of births on that particular island). Rates per 10,000 births should always be used when analyzing data.
