Revisit Geographic Clustering of Diabetic Lower-extremity Amputation in Texas-Mexican Border Counties and Non-Border Counties

Background: Based on 2003 data, lower-extremity amputation (LEA) in diabetic patients was clustered in the Texas-Mexican border counties where majority of population are poor and uninsured. After a decade, none of studies explore LEA rate in those areas and whether LEA rate is related to health conditions in the communities. The objective of the study is to examine whether LEA rate is associated with county’s health conditions. We hypothesize that LEA rate is associated with poor health conditions of the counties.

Method: A cross-sectional study design based on 2010 data was applied.  The data include Texas inpatient data for identifying LEA patients, Texas BRFSS file and Area Resource File for estimating the number of diabetes patients, and the County Health Rankings and Roadmaps providing county’s health conditions. The unit of analysis is the county. The dependent variable is LEA rate, measured by the number of LEA patients divided by the estimated number of diabetes patients in the county. The key independent variables are dummy variables representing counties’ health rankings. A multivariable regression model was used for the analyses. 

Results: 19 of 32 border counties were ranked as the poorest health conditions among all Texas counties. Counties ranked as the poorest health conditions have 18% higher LEA rate than counties ranked as the best health conditions (p<0.001).

Conclusion: Disparity in LEA is related to where patients resided. The approach of public health on improving health conditions of communities would provide the opportunities to reduce disparity in LEA due to geographical difference.