Help With Viewing Asthma Hospitalization and ED Visit Information
Age-adjusted rate
Age adjustment is a statistical process applied to rates of death, emergency department visits, hospitalizations, disease, or other health outcomes. It allows areas with different age structures to be compared. Age confounding occurs when the two populations being compared have different age distributions, and the risk of the outcome varies across age groups. The process of age adjustment changes the amount that each age group contributes to the average rate in each area, so that the overall rates are based on the same age structure. Rates based on the same age distribution can be compared to each other without the presence of confounding by age. Age-adjusted rates were calculated by first multiplying the age-specific asthma hospitalization and emergency department visit rates by age specific weights. The weights used in the age adjustment of asthma data are the proportion of the Standard Population (the U.S. population as enumerated by the Bureau of the Census, 2000) within each age group. The weighted rates are then summed across the age groups to give the age-adjusted rate.
Asthma emergency department visit rate
Asthma emergency department visit (ED visits) rates can provide information about patterns of asthma ED visits over time, by geographic location and by demographics, such as age or sex. Asthma ED visits rates are calculated by dividing the total number of asthma ED visits by the total population in that geographic area in the same years. That figure is than multiplied by 10,000.
Asthma hospitalization rate
Asthma hospitalization rates can provide information about patterns of asthma hospitalizations over time, by geographic location and by demographics, such as age or sex. Asthma hospitalization rates are calculated by dividing the total number of asthma hospitalizations by the total population in that geographic area in the same years. That figure is than multiplied by 10,000.
Region
Maps display three different geographic areas: New York State, New York City and New York State excluding New York City. The New York City and New York State excluding New York City are provided to show regional differences in asthma hospitalization rates.
Map display
Different classification schemes are used to group data for display on a thematic map (a map that focuses on a single type of data). There is no single best data classification method; each has advantages and disadvantages. When creating a thematic map, the user should consider the purpose of the map, the data distribution (if known), and the knowledge level (i.e., mapping and statistical awareness) of the intended audience.
Equal Interval
A thematic map classification scheme where the data are divided by the desired number of data classes, so that the data ranges in each classes is the same (e.g. 10-20, 20-30, 30-40, etc.). The major advantage of Equal interval classification is that the equal intervals are easy to interpret. The major disadvantage of this method is that the data distribution is not considered when determining class breaks for the intervals (only the lower and upper data values are used). This method has been adapted to deal with outliers by truncating the ranges at the upper and lower end of the distributions. Data are displayed using a sequential color scheme.
Percent difference from the mean classification
A thematic map classification scheme where the data are grouped into intervals by the percent increase and decrease from the middle range, typically the mean (average). The major advantage of this classification method is that by using the mean as a dividing point, a contrast of values above and below the mean is easily seen. Data are displayed using divergent color scheme to show differences on either side of the middle range.