Statin initiation and risk of serious respiratory infection: a population-based cohort study of older UK adults using linked health records
Adam J Streeter, Fergus Hamilton, Ian J Wellaway, Lauren R Rodgers, Sarah Walker, Stephen Mullin, André Karch, William Hamilton, William E HenleyAbstract
Background
While statins are typically prescribed to reduce the risk of cardiovascular diseases, they may also offer protection against influenza. We investigated the effect of statins on influenza and related respiratory outcomes in older adults not receiving influenza vaccination in the UK.
Method
We aggregated annual cohorts from 2010 to 2018 comprising UK patients registered in primary care within the UK Clinical Practice Research Datalink, aged ≥65 years on the1st September index date without influenza vaccination two years prior to index. We compared patients who had initiated statins by the index date to those with no recorded statin prescription. Outcomes were acute respiratory infection (ARI), influenza and pneumonia, diagnosed in hospital. Using the prior event rate ratio study design, we adjusted for measured and unmeasured confounding bias, by utilizing data for each outcome recorded in the 1y period prior to index.
Results
Data on 213,372 patients were included for study. Following statin initiation, there was a significant reduction in pneumonia (hazard ratio (HR)= 0.86, 95%CI: 0.78, 0.94) and general ARI (HR=0.83, 95%CI: 0.76, 0.89) diagnosed in hospital, but not for influenza (HR=0.63, 95%CI 0.21, 1.93).
Conclusion
In unvaccinated older adults, statin initiation was associated with a reduced risk of pneumonia and other acute respiratory infections diagnosed in hospital. These findings are consistent with, but do not establish, a protective effect of statins on severe respiratory infection.