Empirical management of community-acquired pneumonia: impact of concurrent A/H1N1 influenza pandemic on guideline implementation

Background: Guideline-concordant therapies have been proven to be associated with improved health and economic outcomes in the treatment of community-acquired pneumonia (CAP). However, actual use of CAP guidelines remains poor, but using tailored interventions looks promising. Based on local observations, we assessed the impact of low-intensity interventions to improve guideline use. Methods: Pre- and post-intervention study with segmented regression analysis in a large tertiary care centre [University Hospitals Leuven (UZL)] and a smaller secondary care control hospital [Ziekenhuis Oost-Limburg (ZOL)] from October 2007 through to June 2010 in Belgium. Results: A total of 477 patients were included in UZL, with 58.5% of the patients treated according to local guidelines. Guideline adherence remained stable, but a decrease (-28.6%; P=0.021) was observed during guideline re-introduction in October 2009. Further analysis showed a high correlation with the concurrent A/H1N1 influenza pandemic (r(point-biserial)=0.683; P=0.045) and with suspected influenza infection (odds ratio=2.70; P=0.038). In ZOL, 326 patients were enrolled, with 69.3% being treated concordantly. A similar, non-significant decrease in guideline adherence was observed after October 2009. Conclusions: Our interventions did not lead to a higher proportion of CAP patients receiving guideline-compliant therapy. Instead, a compliance decrease was observed, coinciding with the peak in the A/H1N1 pandemic in the population. Similar observations could be made in ZOL. The widespread attention for this pandemic may have altered the perception of needed antibiotic therapy for pulmonary infections, bypassing our interventions and decreasing actual guideline compliance. Increased vigilance and follow-up is needed when epidemics with similar impact occur in the future.