Interaction of Post-Traumatic Stress Disorder and Race on Readmissions after Stroke

Background There is limited research on outcomes of patients with post-traumatic stress disorder (PTSD) who also develop stroke, particularly regarding racial disparities. Our goal was to determine whether PTSD is associated with the risk of hospital readmission after stroke and if racial disparities existed. Methods The analytical sample consisted of all veterans receiving care in the Veterans Health Administration (VHA) who were identified as having a new stroke requiring inpatient treatment based on International Classification of Diseases codes. The retrospective cohort data was obtained from the VA Corporate Data Warehouse. The main outcome was any readmission to VHA. The hypothesis that PTSD is associated with readmission after stroke was tested using Cox regression adjusted for patient characteristics with PTSD as a time-varying covariate. Results Our final cohort consisted of 93,652 patients with inpatient stroke diagnosis and no prior VHA codes for stroke starting from 1999 with follow-up through 6-August-2022. Of these patients, 12,916 (13.8%) had comorbid PTSD. Of the final cohort, 16,896 patients (18.0%) with stroke were readmitted. Our fully-adjusted model for readmission found an interaction between African Americans (AA) and PTSD with a hazard ratio of 1.09 (95% CI 1.00-1.20; p<0.05). In stratified models, PTSD has a significant HR of 1.10 (1.02-1.18, p=0.01) for AA but not White veterans 1.05 (0.99-1.11, p=0.10). Conclusion Among AA Veterans who suffered stroke, pre-existing PTSD was associated with increased risk of readmission, which was not significant among White veterans. This study highlights the need to focus on high-risk groups to reduce readmissions after stroke.