Abstract: Background: Pneumonia is the leading cause of infection related mortality. Multilobar pneumonia (MLP) may have poorer outcomes and is a constituent of some prognostic indices. Our aim was to systematically-review and meta-analyse the impact of multi-lobar involvement in pneumonia.Methods: We searched PubMed in June 2012 for studies reporting on the association between MLP and clinical outcomes. Potentially relevant studies were cross checked by two independent reviewers before final inclusion. Odds-ratios (OR) for the association between MLP and mortality, unfavourable outcomes, and poor treatment response were pooled using random effects meta-analysis.Results: Twenty-two studies were included in this report. There were a total of 11,456 pneumonia patients including 2897 (25.3%) patients with MLP. As there was substantial clinical and statistical heterogeneity in the overall dataset, we limited the main meta-analysis to patients with community-acquired pneumonia (CAP). This showed that MLP was associated with increased mortality, OR 2.57 (95% CI: 1.83–3.61), with no statistical heterogeneity (I2=0%). Evidence from other settings suggests that MLP may also be associated with higher likelihood of other poor outcomes such as worsening clinical/radiological status, delayed resolution, and need for mechanical ventilation.Conclusion: MLP appears to be an independent risk factor for mortality in CAP. It may be possible to improve commonly used prognostic indices in CAP by addition of MLP as a criterion.Highlights:
