Alternative Models of Calculating Risk of Heat Death Among Individuals Making Covert Border Crossings from Mexico to Arizona

• Activity Number: 515
• Type: Contributed
• Date/Time: Thursday, August 2, 2007 : 8:30 AM to 10:20 AM
• Sponsor: Section on Statistics in Epidemiology
• Author(s): Mary Mays*+ and Samuel M. Keim and Kendall Allred and Jan Jirsak
• Companies: Arizona State University and Arizona State University and Arizona State University and Arizona State University
• Keywords: estimating risk ; risk communication ; logistic regression ; receiver operating characteristic curve ; heat death ; illegal immigration

Abstract

Background: Heat deaths were rare in Pima County, AZ prior to 2000, but increased steadily from 10 in 1999 to 75-110 in 2002-2005. Data from 2002-2005 indicate that 90% of heat deaths occurred among individuals crossing the Mexico/U.S. border covertly. Defining the relationship between ambient temperatures and risk of heat death is difficult, because the number of covert border crossers can not be measured. Method: Risk of heat death when ambient temperatures exceed 32C was calculated using two different models for estimating the at-risk population, one based on people and one based on opportunity. Five methods were used for evaluating risk: proportions, odds ratios, logistic regression, probit analysis, and receiver operating characteristic curves. Results: People OR = 19.7; Opportunity OR = 19.3. Conclusion: A meaningful estimate of risk can be calculated using an opportunity model.