Oseltamivir and the risk of influenza-related complications and hospitalizations in patients with diabetes

Objective: This subgroup analysis of a retrospective cohort study examined, from a managed care perspective, the risk of influenza-related complications and hospitalizations in patients with diabetes who were prescribed oseltamivir for the treatment of influenza and those who were not prescribed antiviral treatment. Methods: Health insurance claims data from the Thomson Healthcare MarketScan Research Database for 6 influenza seasons (October 1-March 31) between 2000 and 2006 were used to identify patients aged >= 18 years with influenza and diabetes. Patients who received a prescription for oseltamivir within 1 day of a diagnosis of influenza were compared with those who received no antiviral treatment. Outcomes included the frequency of pneumonia, respiratory diagnoses, and otitis media and its complications, and rates of hospitalization within 14 days of the diagnosis of influenza. Cox proportional hazards regression was used to determine the relative risk (RR) of influenza-related complications and hospitalizations. Results: A total of 9090 patients with diabetes and a diagnosis of influenza were identified who met all study, criteria. Of these, 2919 (32%) received a prescription for oseltamivir and 6171 (68%) received no antiviral treatment. Patients receiving oseltamivir had a significant 17% reduction in the risk of respiratory illnesses (RR = 0.83; 95% CI, 0.73-0.93) and a 30% reduction in the risk of hospitalization for any reason (RR = 0.70; 95% CI 0.52-0.94). There were no significant differences between the oseltamivir and control groups in terms of the risks for pneumonia (RR = 0.87; 95% CI 0.64-1.18), otitis media and its complications (RR = 0.963 95% CI 0.48-1.91), or hospitalization for pneumonia (RR = 0.81; 95% CI 0.41-1.58). Conclusion: In this retrospective study, the risk of influenza-associated respiratory illnesses and the number of hospitalizations for any reason were reduced in patients with diabetes who were prescribed oseltamivir compared with an unmatched group that was not prescribed antiviral therapy.