Medication Adherence and Its Effect on Relapse Among Patients Discharged from a Veterans Affairs Posttraumatic Stress Disorder Treatment Program

BACKGROUND: Clinical outcomes in patients with posttraumatic stress disorder (PTSD) can be affected by several factors, including medication adherence. PTSD is associated with an increased likelihood of missed appointments, medication underuse or abuse, and treatment nonadherence. OBJECTIVE: To evaluate medication adherence and its effect on relapse following discharge of veterans from a PTSD residential rehabilitation program (PRRP). METHODS: A retrospective evaluation of drug adherence and relapse in the 12 months following discharge of patients from a PRRP was performed. All veterans who were discharged from January 1, 2005, to December 31, 2006, and were receiving antidepressant therapy were included. Adherence to antidepressant therapy was assessed by electronic prescription claims and defined as a medication possession ratio of at least 0.8 in the year following discharge. Relapse was defined as a hospitalization for psychiatric symptomatology. Predictive factors of adherence were also explored. RESULTS: Twenty-eight of the 82 (34%) veterans included in our study were adherent to medication during the 12 months following discharge. Seventeen (20.7%) veterans were rehospitalized for psychiatric symptoms, but nonadherence was not significantly associated with relapse (p = 0.91). The total number of drugs that a veteran received was related to adherence; patients who had a higher median number of medications were more adherent (p = 0.014). Age, comorbid substance abuse, combat service, and service connection were not associated with drug adherence. CONCLUSIONS: The majority of patients who were discharged from a residential PTSD treatment program were nonadherent to antidepressant drug therapy. One I in 5 veterans with PTSD was rehospitalized within 1 year; however, medication adherence did not affect this outcome.