Overall and cause-specific mortality in Crohn's disease: a meta-analysis of population-based studies. 
An overview of mortality risk among unselected patients with Crohn's disease (CD) is lacking.  We therefore performed a systematic review and meta-analysis of population-based studies on overall and cause-specific mortality in CD.  MEDLINE (January 1965 to February 2008), abstracts from international conferences and reference lists of selected articles were searched systematically.  All articles fulfilling the predefined inclusion criteria were scrutinized for data on population size, time of follow-up, gender, age, and observed to expected deaths.  STATA meta-analysis software was used to calculate overall and cause-specific pooled standardized mortality ratios (SMR, observed/expected).  Nine studies were included with overall SMRs ranging from 0.72-3.2, resulting in a significantly increased pooled SMR of 1.39 (95% confidence interval [CI]: 1.30-1.49).  Regarding cause-specific mortality, a significantly increased risk of death from cancer (SMR 1.50, 95% CI: 1.18-1.92), in particular of pulmonary cancer (SMR 2.72, 95% CI: 1.35-5.45), as well as chronic obstructive pulmonary disease (SMR 2.55, 95% CI: 1.19-5.47), gastrointestinal diseases (SMR 6.76, 95% CI: 4.37-10.45), and genitourinary diseases (SMR 3.28, 95% CI: 1.69-6.35) was observed.  Among unselected patients with CD, overall mortality was slightly but significantly higher than in the general population-primarily explained by deaths from gastrointestinal, respiratory, and genitourinary diseases.  Notably, mortality from colorectal cancer was not increased.