Brief ReportsModifying Instructions on the Posttraumatic Stress Disorder Checklist for Military Populations Does Not Change Symptom ReportingRiviere, Lyndon A. PhD*; Edens, Edward N. PhD*; Adler, Amy B. PhD†; Bliese, Paul D. PhD*; Klocko, Robert P. BA*; Hoge, Charles W. MD*Author Information *Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, MD; and †United States Army Medical Research Unit—Europe, Heidelberg, Germany. Supported by the Military Operational Medicine Research Area Directorate, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD. The material has been reviewed by the Walter Reed Army Institute of Research. There is no objection to its presentation and/or publication. The opinions or assertions contained herein are the private views of the author, and are not to be construed as official, or as reflecting true views of the Department of the Army or the Department of Defense. Send reprint requests to Lyndon Riviere, PhD, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, 503 Robert Grant Ave, Silver Spring, MD 20910. E-mail: [email protected]. The Journal of Nervous and Mental Disease: March 2011 - Volume 199 - Issue 3 - p 199-202 doi: 10.1097/NMD.0b013e31820caee4 Buy Metrics Abstract This study investigates whether modifying the instructions of the Posttraumatic Stress Disorder Checklist (PCL) for military survey research changes posttraumatic stress disorder (PTSD) symptom reporting or prevalence. The sample consisted of 1691 soldiers who were randomly assigned to complete 1 of 3 versions of the PCL, which differed only in the wording of the instructions. Group differences in demographic variables, combat exposure, mean PTSD symptoms, and PTSD prevalence estimates were examined. Results showed that there were no statistically significant differences in the outcomes across the PCL versions. The findings indicate that researchers may make modifications to the PCL instructions to meet research needs without affecting PTSD symptom reporting or prevalence estimates. © 2011 Lippincott Williams & Wilkins, Inc.