Adolescent sexual health outcomes and program evaluation using geographical information systems (GIS)

Interventions for adolescent sexual health are rarely evaluated using outcome maps for sexually transmitted infections (STIs) and teen births. Using geographical information system (GIS) allows easy visualization of occurrence and trends in these outcomes. Objective: To 1) describe GIS mapping of sexual heath outcomes such as STIs and teen births and 2) demonstrate GIS maps from an adolescent sex education program. Methods: Data on chlamydia infections and teen births are obtained for the program and nonprogram areas in a Texas border County. Concurrently, boundary files for circumscribed intervention and nonintervention areas are procured. Using GIS, these data are then geocoded and placed on a map. Rates are calculated for the purpose of comparison. Comparison of case incidence and rates in program and nonprogram areas over time identifies changes and trends in sexual health outcomes. Results: Maps from an adolescent sexual health education program in school districts in a Texas County will be demonstrated. GIS maps from our program are used to compare sexual health outcomes geographically (between County school districts) as well as temporally (years). The maps show decreases in teen births and chlamydia in the program areas as compared to non-program areas over time. Further analyses using GIS, such as spatial analyses, will also be discussed. Various challenges to the use of GIS include ensuring data integrity, address matching, and collection of updated geographical information of program and comparison areas. Conclusion: Use of GIS for sexual health outcome data is an effective strategy for program evaluation.