Looking at Stroke Mortality, Hospitalization and Service Delivery through Maps Presenters from the Iowa Department of Public Health Terry Meek, GIS Training Team Leader and Heart Disease and Stroke Prevention Program Manager Timothy Wickam, GIS Training Team Member and Environmental Epidemiologist 1

Rationale for GIS Map Training The ability of the Iowa Department of Public Health to use data to drive policy efforts and program activities is critical to the department’s mission to promote and protect the health of Iowans. The department also has an obligation to share data with Local Public Health Agencies and others that is useful to them in their health needs and planning efforts. Geographic Information System (GIS) Mapping allows us to plot different types of spatial data by geographical area (deaths by county, deaths by zip code or census tracts) so that we can analyze data in a more visual manner. In 2012, 10 IDPH employees were trained in GIS Mapping through a competitive CDC competition. University of Michigan trainers came to IDPH for three separate two-day sessions over a six-month period. The stroke maps we will look at today were a part of the work projects from that training. 2

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Stroke Death Rates in Iowa, In these maps, stroke deaths were defined as those with an underlying cause of death classified by the International Classification of Diseases, 10th Revision (ICD-10) codes as [This excludes TIAs.] There are substantial geographic disparities in stroke death rates in Iowa. During , eight counties around the Cedar Rapids area had the lowest stroke death rates, while southeastern Iowa had the highest stroke death rates. 4

The southeast corner (SE) of the state contains 11 counties from Lucas and Wayne on the left to Henry at the right. Three counties in this corner had the highest stroke death rates in the state: Monroe (91/100,000), which was 110% higher than the state average (43/100,000), Henry (73.5% higher) and Wayne (67.4 higher). Forty-six counties had a stroke death rate higher than the state average; while 51 counties had rates lower than the state average, and 2 counties had insufficient data for analysis. 5

The overall stroke death rate for the state has been declining in Iowa over the past 10 years, yet 5 counties had increased stroke death rates from to : Monroe (SE), Mahaska (SE), Lucas (SE), Wayne (SE), and Hardin (North Central). Ninety-two counties had decreased stroke death rates, and 18 of them had decreased more than 20% during the past ten years. Even though we have seen a decrease, it is important to acknowledge that stroke remains the 4 th leading cause of deaths in Iowa. 6

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Stroke Death Rate Change from to The four small maps on the right used quintiles based on the same scale to present the data across all the maps for each of the four periods of time. The big map shows the percentage of change in each county over the past 20 years based on the 4 small maps on the right. Ten counties had increased stroke death rates over the past 20 years, and 8 of them had double digit increased rates during the 20-year period. Harrison and Monroe counties had the highest increased rates: 34% and 32%, respectively. Eighty-seven counties had decreased stroke death rates during the 20 years, and 8 of them had decreased more than 50% over the past 20 years. Benton, in the Cedar Rapids area, and Delaware, neighboring the Cedar Rapids area, both had decreased stroke death rates by 59% over the past 20 years. 8

Stroke Hospitalizations of Iowa Residents in Iowa Hospitals, The next map displays the age adjusted rate per 1,000 population of stroke hospitalizations of Iowa residents in Iowa Hospitals from In the 37 hatch-marked counties the rates may be a significant underestimate of the true rates, because greater than 5% of resident hospitalizations occur in out of state hospitals, and are not included in the data. 9

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Stroke Hospitalizations of Iowa Residents in Iowa Hospitals, (Cont.) The pattern of counties where rates may be unreliable is concentrated in the western and north east parts of the state; this pattern is consistent with proximity to major out-of-state health facilities in Nebraska, South Dakota, and Minnesota. 11

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Stroke Hospitalizations of Iowa Residents in Iowa Hospitals, by Age group, This pair of maps displays the disparity in rates of stroke hospitalizations of Iowa residents in Iowa hospitals ages and ages 65 and over. The maps show that Iowans 65 and over have a higher incidence of hospitalization for stroke than Iowans 35-64, and that this disparity is generally independent of geographic location. 13

Stroke Hospitalizations of Iowa Residents in Iowa Hospitals, by Age group, (Cont.) The state-wide age group specific rates of hospitalization are 2.3 for Iowans age and 23.7 for Iowans ages 65 and over, this compares to the overall state-wide rate of The range of age group specific rates at the county level is for Iowans age and for Iowans ages 65 and over. 14

Stroke Hospitalizations of Iowa Residents in Iowa Hospitals, by Gender, The next pair of maps displays the disparity in rates of stroke hospitalizations of Iowa residents in Iowa hospitals among women and men. The maps show in general men have a higher hospitalization rate than women. The state-wide gender specific rates of hospitalization are 3.5 for women and 4.5 for men. The range of gender specific rates at the county level is for women and for men. 15

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Iowa Primary Stoke Centers and Stroke Capable Hospital Service Areas The last map in our presentation documents the service area of primary stroke centers and stroke capable hospitals in Iowa. The map demonstrates the 30-minute service area from both Primary Stroke Centers (PSC) and Stroke Capable Hospitals. The indicated service area polygons demonstrate drive times towards the facility by analyzing the road network. 10 Stroke Capable Hospitals are located within 30 minutes of a PSC. 48.2% of Iowa’s population is within 30 minutes of a PSC and 79.7% is within 30 minutes of a Stroke Capable Hospital. Considering both PSC and Stroke Capable Hospitals, 94.0% of Iowa’s population is within 30 minutes of either a Level 1 (PSC) or a Level 2 (Stroke Capable Hospital) facility. * [* U.S. Census Bureau-Centers of Population by state and census tract] 17

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Questions ? Terry Meek (515) 19