Posttraumatic stress disorder and nonadherence to medications prescribed for chronic medical conditions: A meta-analysis

Background: Patients with posttraumatic stress disorder (PTSD) are at increased risk for adverse consequences from comorbid medical conditions. Nonadherence to medications prescribed to treat those comorbid conditions may help explain this increased risk. We sought to determine the association between PTSD and medication nonadherence and whether it varied according to the type of event inducing the PTSD. Methods: Prospective observational cohort or cross-sectional studies relating PTSD and nonadherence among adults prescribed medications for a chronic medical illness were identified by searching MEDLINE, EMBASE, PsycINFO, the Cochrane Library, CINAHL, SCOPUS, and the PILOTS Database and by hand-searching bibliographies from selected articles. Individual estimates of odds ratios were pooled using random effects meta-analysis with inverse variance weighting. Articles were pooled separately according to whether PTSD was induced by a medical versus non-medical event. Outcomes: Sixteen articles comprising 4483 patients met eligibility criteria. The pooled effect size of the risk of PTSD to medication nonadherence was OR 1.22 (95% CI, 1.06–1.41). Among the 6 studies of medical event-induced PTSD, the OR was 2.08 (95% CI, 1.03–4.18); p = 0.04. Among the 8 studies in which PTSD was not induced by a medical event, the OR was 1.10 (95% CI, 0.99–1.24); p = 0.09. Interpretation: Patients with PTSD were more likely to be nonadherent to medications prescribed for chronic medical conditions – an association that may exist specifically when PTSD was induced by a medical event. Medications may serve as aversive reminders among survivors of acute medical events, magnifying avoidance behaviors characteristic of PTSD. Funding: NHLBI.