Anxiety and Posttraumatic Stress Disorder Among Medicare Beneficiaries After Traumatic Brain Injury.

OBJECTIVE

To estimate rates of anxiety and posttraumatic stress disorder (PTSD) diagnoses after traumatic brain injury (TBI) among Medicare beneficiaries, quantify the increase in rates relative to the pre-TBI period, and identify risk factors for diagnosis of anxiety and PTSD.

PARTICIPANTS

A total of 96 881 Medicare beneficiaries hospitalized with TBI between June 1, 2006 and May 31, 2010.

DESIGN

Retrospective cohort study.

MEASURES

Diagnosis of anxiety (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] codes 300.0x) and/or PTSD (ICD-9-CM code 309.81).

RESULTS

After TBI, 16 519 (17%) beneficiaries were diagnosed with anxiety and 269 (0.3%) were diagnosed with PTSD. Rates of anxiety and PTSD diagnoses were highest in the first 5 months post-TBI and decreased over time. Pre-TBI diagnosis of anxiety disorder was significantly associated with post-TBI anxiety (risk ratio, 3.55; 95% confidence interval, 3.42-3.68) and pre-TBI diagnosis of PTSD was significantly associated with post-TBI PTSD (risk ratio 70.09; 95% confidence interval 56.29-111.12).

CONCLUSION

This study highlights the increased risk of anxiety and PTSD after TBI. Routine screening for anxiety and PTSD, especially during the first 5 months after TBI, may help clinicians identify these important and treatable conditions, especially among patients with a history of psychiatric illness.