The Research Electronic Data Capture platform (Harris et al., 2009) was used to program the National Stressful Events Survey questionnaire and to record all survey data. All prevalence algorithms were computed as defined above using syntax programmed in SPSS 20. Taylor-series linearization was used for all standard error estimation given the weighted design of the study. The SAS-Callable SUDAAN software (Version 11.0; Research Triangle Institute, 2012) was used to generate weighted survey data, prevalence estimates, and χ2 tests. The z-score comparisons with other prevalence data were estimated with weighted prevalence estimates and survey-adjusted standard errors to compare whether PTSD prevalence was significantly different between the DSM-IV and the DSM-5. Difference scores were created and discordant pairs (e.g., diagnosis positive based on the DSM-IV, diagnosis negative based on the DSM-5) were analyzed using a dependent sample t test in Stata 12.
