Abstract
BACKGROUND: Posttraumatic stress disorder (PTSD) is often underdiagnosed based on medical records. This study aimed to estimate the prevalence and health care utilization of individuals with PTSD and other trauma-related disorders in a large, integrated health care system. METHODS: Adults (between the ages of 18 and 65) with Kaiser Permanente Northern California membership and ≥ 1 outpatient visit in 2022 were eligible. Unspecified/other specified trauma and stressor-related disorder, acute stress disorder, and PTSD were based on diagnosis codes from the International Classification of Diseases, 10th Revision, Clinical Modification. The Primary Care PTSD (PC-PTSD) Scale was used as a screening tool. Prevalence was assessed overall and among the subset of patients seen in primary care, psychiatry, and addiction medicine. To contextualize health care utilization, the authors compared patients with trauma-related disorders to those with major depressive disorder. RESULTS: Of the 2,128,670 eligible adults, the overall prevalence of trauma-related diagnoses and positive screening on PC-PTSD was 4.9% (103,947); 1.3% (n = 27,670) had PTSD, 1.9% (n = 41,205) had unspecified/other specified trauma and stressor-related disorder, 0.1% (n = 1818) had acute stress disorder, and 1.6% (n = 33,254) screened positive on PC-PTSD without a trauma-related International Classification of Diseases code. Prevalence of trauma-related diagnoses by department was 18.3% (n = 47,516) in psychiatry, 16.5% (n = 3816) in addiction medicine, and 3.4% (n = 67,469) in primary care. There were no clinically meaningful differences in health care utilization between those with trauma-related diagnoses compared with major depressive disorder. CONCLUSION: Broadly defining trauma-related disorders and substantial symptoms may provide a more accurate representation of the actual prevalence of PTSD in a health care system. These data may help health care leaders plan treatment options for this diverse group of individuals.