We studied post-traumatic stress disorder (PTSD), a severe trauma-related mental disorder, and systemic lupus erythematosus (SLE) risk in a large, diverse population enrolled in Medicaid, a U.S. government-sponsored health insurance program for low-income individuals.
We identified SLE cases and controls among patients 18-65 years old enrolled in Medicaid for ≥ 12 months in the 29 most populated US states from 2007 to 2010. SLE and PTSD case status were defined based on validated patterns of ICD-9 codes. Index date was the date of the first SLE code. Controls had no SLE codes but had another inpatient or outpatient code on the index date, and were matched 1:10 to cases by age, sex and race. Conditional logistic regressions calculated odds ratios (OR) and 95% confidence intervals (CI) for the association of PTSD with incident SLE, adjusting for smoking, obesity, oral contraceptive use, and other covariates.
10,942 incident SLE cases were matched to 109,420 controls. Prevalence of PTSD was higher in SLE cases at 10.74 cases of PTSD per 1,000 (95% CI 9.37-12.31) versus 7.83 (95% CI 7.42-8.27) in controls. The multivariable-adjusted OR for SLE among those with PTSD was 2.00 (95% CI 1.64-2.46).
In this large, racially and sociodemographic diverse US population, we found patients with prior PTSD diagnosis had twice the odds of a subsequent diagnosis of SLE. Studies are necessary to clarify the mechanisms driving the observed association and to inform possible interventions.