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The 130th Annual Meeting of APHA |
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The 130th Annual Meeting of APHA |
Kenneth G. Keppel, PhD, NCHS/Division of Health Promotion Statistics, Centers for Disease Control and Prevention, 6525 Belcrest Road, Rm 770, Hyattsville, MD 20782, 301 458-4310, Kkeppel@cdc.gov and Jeffrey N. Pearcy, MS, Division of Health Promotion Statisics, Centers for Disease Control and Prevention, 6525 Belcrest Rd., Rm 770, Hyattsville, MD 20782.
Disparity can be measured between two rates or among several rates. The disparity between rates at one point in time can be compared with the disparity between comparable rates at a second point in time and the disparity between rates for one indicator can be compared with the disparity between rates for other indicators. However, when there are more than two groups, it can be difficult to draw a general conclusion about changes in disparity over time or about the degree of disparity across indicators.
Summary measures can be used to quantify differences among several rates. The simplest summary measures are based on the average of absolute or relative differences. The mean deviation is a measure of the average of absolute differences between group rates; the index of disparity expresses the mean deviation as a percent of the total population rate; and the average of ratios is a measure of the average of relative differences. Summary statistics make it possible to examine changes in differences among rates over time and to compare differences among rates across indicators.
The use of summary measures is illustrated and the following issues are discussed: the choice of a reference point for measuring disparity, the effect of squaring differences or ratios, and the need to interpret summary measures in terms of underlying rates.
Learning Objectives:
Keywords: Minority Health,
Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.