Spatial Analysis of Tuberculosis (TB) in Texas

Presented by:
Amber Brooke Trueblood, MPH
Intern Division for Regional and Local Health Services
Texas Department of State Health Services

Transcript

1. Spatial Analysis of Tuberculosis (TB) in Texas Presented by: Amber Brooke Trueblood, MPH Intern Division for Regional and Local Health Services Texas Department of State Health Services
2. Presentation Outline I. Educational Background II. Project Goal and Information III. Tuberculosis Background IV. Access to Care Background V. Statistical Analysis Background VI. Project Maps VII. Poisson Regression Findings VIII. Conclusion
3. Educational Background • BA Sociology, St. Edward’s University • MPH Health Promotion & Behavioral Science, The University of Texas Health Science Center at Houston • In Progress DRPH Epidemiology & Environmental Health, Texas A&M Health Science Center School of Public Health
4. GIS and Public Health • Through utilizing GIS we are better able to understand: • Populations at risk • Health Outcomes • Risk Factors • Associations between Risk Factors and Health Outcomes • Health Interventions
5. Project • Project Goal ─ Utilize geographic information systems (GIS) methods and spatial analysis to better understand Tuberculosis in Texas
6. Tuberculosis Background • Tuberculosis Background • 2013 • Texas Rate: 4.6 per 100,000 persons • 1,222 cases • United States Rate: 3.0 per 100,000 persons • 9,582 cases
7. Access to Care Background Access to Care Statistics Texas Rural Texas National # of Registered Nurses per 100,000 737 507 874 # of Primary Care Physicians per 100,000 70 54 80
8. Spatial Analysis Background • Moran’s I (Spatial Autocorrelation) • Null Hypothesis: Feature values are randomly distributed across the study area. • Spatial Autocorrelation Tool • Evaluates if pattern is clustered, dispersed, or random
9. Spatial Analysis Background
10. Spatial Analysis Background • Hot Spot Analysis • Hot Spot Analysis tool assesses whether high or low values of an outcome cluster spatially • Utilizes the Getis-Ord Gi* Statistic • Produces z-scores and p-values • Three Outcomes 1. Hot Spot=High Occurrence • High z-score and small p-value 2. Cold Spot=Low Occurrence • Negative z-score and small p-value 3. No Significance=No Spatial Clustering
11. Spatial Analysis Background • Poisson Regression • Statistical measure that determines the strength of the relationship between an outcome and independent variables. • Used for Count or Rate Outcome, such as TB
12. Dallas Austin El Paso Houston Lubbock Del Rio Amarillo Brownsville San Antonio Tuberculosis Total Cases in Texas Sources: U.S. Census,2010; TPWD,2014;TX DSHS,2014 Mapped by: Amber Trueblood: 2014 Note: In 2013, there were 9,582 cases of tuberculosis reported. Of these 1,222 were in Texas. Tuberculosis Total Cases, 2009-2013 1 - 44 45 - 169 170 - 438 439 - 1604 Major Cities
13. Tuberculosis 5 Year Average Rates in Texas Sources: U.S. Census,2010; TPWD,2014;TX DSHS,2014 Mapped by: Amber Trueblood: 2014 Note: In 2013, the Texas tuberculosis rate was 4.6 per 100,000 compared to the United States rate of 3.0 per 100,000. Tuberculosis Rate, 2009-2013 0.5 - 5.2 5.3 - 14.5 14.6 - 36.2 36.3 - 77.1
14. Texas Five year TB rate with 2013 Physician Rate Sources: U.S. Census,2010; TPWD,2014;TX DSHS,2014 Mapped by: Amber Trueblood: 2014 Note: In 2013, the Texas tuberculosis rate was 4.6 per 100,000 compared to the United States rate of 3.0 per 100,000. Physician Rates, 2013 1 - 50 51 - 100 101 - 300 301 - 500 Tuberculosis Rate, 2009-2013 0.5 - 5.2 5.3 - 14.5 14.6 - 36.2 36.3 - 77.1
15. Texas Five year TB rate with 2013 Physician Assistant Rate Sources: U.S. Census,2010; TPWD,2014;TX DSHS,2014 Mapped by: Amber Trueblood: 2014 Note: In 2013, the Texas tuberculosis rate was 4.6 per 100,000 compared to the United States rate of 3.0 per 100,000. Physician Assistant Rate, 2013 0 - 25 26 - 50 51 - 100 101 - 200 Tuberculosis Rate, 2009-2013 0.5 - 5.2 5.3 - 14.5 14.6 - 36.2 36.3 - 77.1
16. Texas Five year TB rate with 2013 Nurse Practitioner Rate Sources: U.S. Census,2010; TPWD,2014;TX DSHS,2014 Mapped by: Amber Trueblood: 2014 Note: In 2013, the Texas tuberculosis rate was 4.6 per 100,000 compared to the United States rate of 3.0 per 100,000. Tuberculosis Rate, 2009-2013 0.5 - 5.2 5.3 - 14.5 14.6 - 36.2 36.3 - 77.1 Nurse Practitioner Rate, 2013 0 - 25 26 - 50 51 - 100 101 - 200
17. Texas Five year TB rate with Number of Local Health Departments (LHDs) Sources: U.S. Census,2010; TPWD,2014;TX DSHS,2014 Mapped by: Amber Trueblood: 2014 Note: In 2013, the Texas tuberculosis rate was 4.6 per 100,000 compared to the United States rate of 3.0 per 100,000. Tuberculosis Rate, 2009-2013 0.5 - 5.2 5.3 - 14.5 14.6 - 36.2 36.3 - 77.1 Number of LHDs 1 2 - 3 4 - 7 8 - 12
18. Texas Five year TB rate with Percent Uninsured Sources: U.S. Census,2010; TPWD,2014;TX DSHS,2014 Mapped by: Amber Trueblood: 2014 Note: In 2013, the Texas tuberculosis rate was 4.6 per 100,000 compared to the United States rate of 3.0 per 100,000. Tuberculosis Rate, 2009-2013 0.5 - 5.2 5.3 - 14.5 14.6 - 36.2 36.3 - 77.1 Percent Uninsured,2012 15.5 - 29.9 30.0 - 34.9 35.0 - 52.3
19. Texas Five year TB rate with Median Income Sources: U.S. Census,2010; TPWD,2014;TX DSHS,2014 Mapped by: Amber Trueblood: 2014 Note: In 2013, the Texas tuberculosis rate was 4.6 per 100,000 compared to the United States rate of 3.0 per 100,000. Tuberculosis Rate, 2009-2013 0.5 - 5.2 5.3 - 14.5 14.6 - 36.2 36.3 - 77.1 Median Income,2012 <$25,000 $25,000 - $35,000 $35,000 - $50,000
20. Texas Five year TB Hot Spot Analysis Sources: U.S. Census,2010; TPWD,2014;TX DSHS,2014 Mapped by: Amber Trueblood: 2014 Note: In 2013, the Texas tuberculosis rate was 4.6 per 100,000 compared to the United States rate of 3.0 per 100,000. Tuberculosis Hot Spots Hot Spot-90% Confidence Hot Spot-95% Confidence Hot Spot-99% Confidence Border County Texas DSHS Health Service Regions
21. Hot Spot Analysis Findings • 20 counties in Texas had higher than expected rates of TB • 15 were border counties • 18 counties were in Health Service Region 8 and 11 • Region 8: Nine Counties • Region 11: Nine Counties • Region 9/10: Two Counties
22. Poisson Regression Findings Variable Estimate (Exp Value) 95% Confidence Interval P-Value Intercept 2.3821 (10.8276) 1.6448, 3.1195 <.0001 Physician Rate 0.0061 (1.0061) 0.0049, 0.0073 <.0001 Physician Assistant Rate -0.0059 (0.9941) -0.0098, -0.0021 0.0024 Nurse Practitioner Rate -0.0117 (0.9883) -0.0154, -0.0080 <.0001 Frontier Status 0.8010 (2.2277) 0.6064, 0.9955 <.0001 Border Status -1.3960 (0.2475) -1.5888, -1.2032 <.0001 Median Income -0.0000 (1) -0.0000, -0.0000 <.0001 Local Health Department 0.0904 (1.09461) 0.0356, 0.1452 0.0012
23. Poisson Regression Findings • Major Findings: • Frontier Classification • Non-frontier county status increased the expected tuberculosis rate by a factor of 2.23 compared to frontier counties. • Border Status • Being a non-border county decreased the expected tuberculosis rate by a factor of 0.25 compared to border counties.
24. Project Limitations • Limited Data Availability • Secondary Data Analysis • Date of Available Data • Using Rates vs Counts • Local Health Departments (LHDs) Limited Available Information • Cannot differentiate services provided by each LHDs
25. Conclusion • Through combining GIS and statistical methods, the project established spatial distribution of tuberculosis and associated risk factors, as well as determined hot spots and significant predictors.
26. Questions Thank you for attending today. Do you have any questions or comments?
27. References • ArcGIS. (2014). Geographically Weighted Regression (GWR) (Spatial Statistics) . Retrieved on April 4, 2014 from http://resources.arcgis.com/en/help/main/10.1/index.html#//005p00000021000000 • Shah, Tayyan Ikram; Bell, Scott.(2013). Exploring the Intra-Urban Variations in the Relationship among Geographic Accessibility to PHC Services and Socio-demographic Factors. Conference HealthGIS. • Texas Department of State Health Services. (2013). Texas TB Data (2008-2012). Retrieved on March 3, 2014, from https://www.dshs.state.tx.us/idcu/disease/tb/statistics/ • Window on State Government. (2013). Texas in Focus: A View of Opportunities. Retrieved on May 4, 2014, from http://www.window.state.tx.us/specialrpt/tif/healthcare.html