The impact of adherence to guidelines for hospitalized community-acquired pneumonia on health outcomes and mortality: A retrospective cohort study

Introduction and objectives: Adherence to validated guidelines has a crucial importance in guiding management of hospitalized community-acquired pneumonia (CAP). We aimed to evaluate the adherence to guidelines over time and to assess its impact on mortality and clinical outcomes. Methods: We performed an observational retrospective study comparing two cohorts of patients admitted to hospital in 2005, i.e., just after the implementation of CAP guidelines, and in 2012, i.e., 7 years after their original implementation. We included all patients with diagnosis of pneumonia and/or related complications. We investigated performance indicators suggested by guidelines. Results: 564 patients were eligible for inclusion. Pneumonia Severity Index calculation was better documented in 2012 (25.23%) compared to 2015 (17.70%; p=0.032), but adherence of empiric antibiotic therapy to guidelines was lower in 2012 (56.70%) than in 2005 (68.75%; p=0.004). Adherence did not appear to be associated with in-hospital mortality nor 30-day mortality after adjustment for potential confounders. Adherence was associated with a shorter mean length of hospital stay both in 2005 (-2.65 days; 95%CI -4.73,-0.58) and 2012 (-3.05 days; 95%CI -4.75,-1.36) and a shorter mean duration of antibiotic therapy (respectively -2.37 days; 95%CI -4.41,-0.34; and -1.88; 95%CI -3.50,-0.27). Conclusions: Adherence to guidelines changed over time, with no effects on mortality but with an apparent reduction in length of hospital stay and duration of antibiotic therapy. Specific clinical training and hospital control policies might help to achieve a greater adherence to guidelines.