The association between oseltamivir use and adverse neuropsychiatric outcomes among TRICARE beneficiaries, ages 1 through 21 years diagnosed with influenza

Recent reports out of Japan have linked therapeutic use of the oral neuraminidase inhibitor oseltamivir with adverse neuropsychiatric outcomes in adolescents. Objective: To assess if protective measures should be taken to mitigate potential adverse outcomes among United States Department of Defense (DoD) pediatric beneficiaries who are prescribed oseltamivir therapeutically. Study Group: DoD healthcare beneficiaries, ages 1 through 21 years, who received a diagnosis of influenza from 1 October 2006 through 30 September 2007. Methods: A retrospective cohort study using electronic healthcare service and pharmacy fill. Cross tabulations and propensity-adjusted logistic regression analyses were performed to compare the frequency of adverse neuropsychiatric outcomes among those treated therapeutically with oseltamivir with those that were not. Results: The prevalences of neuropsychiatric diagnoses following the influenza diagnosis overall and among the treated and untreated groups were 3.5%, 3.0%, and 3.8%, respectively (p < .05). A statistically significant protective effect was associated with oseltamivir treatment (prevalence odds ratio (POR) = 0.82 (95% Cl, 0.69, 0.96)) in a propensity-adjusted regression model. The model significantly associated increasing patient age with the likelihood of an adverse neuropsychiatric outcome, but the associations with patient gender and parental rank, a proxy used for socioeconomic status, were not statistically significant. Conclusions: Our retrospective study found no evidence that oseltamivir treatment for influenza increased the risk of adverse neuropsychiatric outcomes among the study population. An additional study focusing on prospective medical surveillance of influenza patients is warranted.