Clinical outcomes of early aspirin versus non-aspirin NSAID use in adults hospitalized with influenza: A retrospective study

Seasonal influenza remains a major cause of morbidity and mortality worldwide. Although neuraminidase inhibitors improve clinical outcomes, influenza-related deaths persist. We evaluated the associations of early aspirin and non-aspirin nonsteroidal anti-inflammatory drug (NSAID) use with clinical outcomes in adults hospitalized with influenza. This retrospective study included adults admitted to the University of Minnesota Medical Center from 2016 to 2018. Multivariable logistic and Cox regression models adjusted for age, sex, race, smoking status, influenza vaccination status, and cardiovascular burden were used to evaluate the associations of early aspirin and NSAID use with clinical outcomes. Among 2,816 patients screened, 320 had laboratory-confirmed influenza. Compared with unvaccinated patients, vaccinated patients had lower rates of ICU admission (11% vs. 24%; P = 0.003) and ventilatory support (6% vs. 15%; P = 0.009). In unadjusted analyses, aspirin users had higher rates of cardiovascular complications (27% vs. 16%; P = 0.028) and lower 3-year survival (57% vs. 72%; P = 0.008). In contrast, NSAID users had lower rates of ICU admission (7% vs. 18%; P = 0.042), cardiovascular complications (4% vs. 23%; P = 0.001), and renal complications (9% vs. 25%; P = 0.010), and higher 1-year (98% vs. 78%; P = 0.0004) and 3-year survival (89% vs. 63%; P = 0.0001). After adjustment, aspirin use was not independently associated with any study outcome. Early NSAID use was independently associated with lower odds of renal complications (aOR, 0.35; 95% CI, 0.13–0.97; P = 0.044) and lower hazards of 1-year (aHR, 0.11; 95% CI, 0.01–0.81; P = 0.030) and 3-year mortality (aHR, 0.33; 95% CI, 0.14–0.77; P = 0.011). Sensitivity analyses using the Charlson Comorbidity Index yielded similar findings. Prospective studies are needed to determine whether early non-aspirin NSAID use improves clinical outcomes in adults hospitalized with influenza.