Pragmatic trial: Oseltamivir of uncertain benefit in patients with flu-like symptoms

Reference

Butler CC, van der Velden AW, Bongard E, et al. Oseltamivir plus usual care versus usual care for influenza-like illness in primary care: an open-label, pragmatic, randomised controlled trial. Lancet 2020;395(10217):42-52.

Synopsis

These authors recruited patients from primary care settings who were at least one year of age and had influenza-like symptoms lasting no more than 3 days. The study took place during 3 consecutive winters. In a pragmatic open-label design, patients were assigned, using a response adaptive randomization system, to receive 5 days of oseltamivir (n = 1629) or their primary care clinician's usual care (n = 1637). Each patient was formally tested for influenza. Additionally each patient, or their caregiver, was asked to keep a daily symptom diary for the 2 weeks following enrollment. The researchers adapted the diaries for children (for example, clinginess for nonverbal children became a proxy for headache and myalgias). At the end of the study period, 91 of the patients (6%) assigned to oseltamivir either dropped out or discontinued medication and 104 patients in the usual care group (7%) either dropped out or discontinued treatment. The authors did not include these patients into their analysis, so it was not really an intention-to-treat analysis. At baseline, the patients in each group were comparable, including the severity and duration of their symptoms. Only 10% of the patients had received influenza vaccinations. Additionally, approximately half the patients had a positive test result for influenza—close to evenly split between types A and B. At the end of the evaluation period, for every age stratum, regardless of symptom severity and duration, and whether or not the patient had a comorbid condition, the patients who received oseltamivir experienced faster recovery than those who received usual care. Overall, the average duration was one day less for patients taking oseltamivir. Older patients, those with comorbidities, and those with longer symptom duration at baseline tended to recover 2 to 3 days faster if they took oseltamivir.