Abstract: | The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM‐5) introduced numerous revisions to the fourth edition's (DSM‐IV) criteria for posttraumatic stress disorder (PTSD), posing a challenge to clinicians and researchers who wish to assess PTSD symptoms continuously over time. The aim of this study was to develop a crosswalk between the DSM‐IV and DSM‐5 versions of the PTSD Checklist (PCL), a widely used self‐rated measure of PTSD symptom severity. Participants were 1,003 U.S. veterans (58.7% with PTSD) who completed the PCL for DSM‐IV (the PCL‐C) and DSM‐5 (the PCL‐5) during their participation in an ongoing longitudinal registry study. In a randomly selected training sample (n = 800), we used equipercentile equating with loglinear smoothing to compute a “crosswalk” between PCL‐C and PCL‐5 scores. We evaluated the correspondence between the crosswalk‐determined predicted scores and observed PCL‐5 scores in the remaining validation sample (n = 203). The results showed strong correspondence between crosswalk‐predicted PCL‐5 scores and observed PCL‐5 scores in the validation sample, ICC = .96. Predicted PCL‐5 scores performed comparably to observed PCL‐5 scores when examining their agreement with PTSD diagnosis ascertained by clinical interview: predicted PCL‐5, κ = 0.57; observed PCL‐5, κ = 0.59. Subsample comparisons indicated that the crosswalk's accuracy did not differ across characteristics including gender, age, racial minority status, and PTSD status. The results support the validity of this newly developed PCL‐C to PCL‐5 crosswalk in a veteran sample, providing a tool with which to interpret and translate scores across the two measures. |