Community-acquired pneumonia mortality: a potential link to antibiotic prescribing trends in general practice.

Background: Community prescribing of antibiotics has decreased substantially in the UK in recent years. We examine the association between pneumonia mortality and recent changes in community-based antibiotic prescribing for lower respiratory tract infections (LRTI).
Methods: Retrospective analysis of aggregated data for pneumonia mortality, influenza incidence, and antibiotic prescribing for LRTI in England and Wales during 12-week winter periods between 1993/94 and 1999/2000.
Results: Winter antibiotic prescribing for LRTI showed a 30.0% decline since 1995/96. Over the same period, there was a 50.6% increase in winter excess pneumonia mortality adjusted for influenza incidence. Negative binomial regression analysis showed that the incidence of influenza alone had a significant association with winter pneumonia mortality (P<0.001). The analysis also showed the reduction in antibiotic prescribing had a small but significant association with mortality (P<0.001), when simultaneously modelling for influenza incidence.
Conclusions: Our findings suggest an association between recent reductions in antibiotic prescribing for LRTI in general practice and an increase in pneumonia mortality in England and Wales. This retrospective study of aggregate data represents the first attempt to assess the effect of limiting antibiotic prescribing on patient outcomes, and highlights the need to identify which patients benefit from antibiotic treatment for LRTI.