Role of acute diverticulitis in the development of complicated colonic diverticular disease and 1-year mortality after diagnosis in the UK: population-based cohort study

Abstract

Objective: To determine the risk of developing complicated colonic diverticular disease (CCDD) with prior episodes of acute diverticulitis and determine the mortality of the spectrum of CCDD.

Design: Population-based cohort study.

Setting: Computerised records from the General Practice Research Database linked to Hospital Episode Statistics data from the UK.

Participants: Patients and controls registered in the General Practice Research Database from 1990 to 2007.

Main outcome measures: Mortality was calculated and Cox regression modelling used to provide adjusted HRs and 95% CI. Logistic regression was used to model the effect of prior acute diverticulitis on the development of complications.

Results: 2950 patients (1872 (63.5%) female) had a diagnosis of CCDD (8739 controls). A total of 1042 (35.3%) patients died compared with 2062 (23.6%) controls. Most excess deaths occurred in the first year after the complication. Patients with a perforation/abscess had a 4.5-fold increase in 1-year mortality (HR 4.55, 95% CI 3.74 to 5.52) compared with the general population, whereas those with a fistula or stricture had a 2.5-fold increase in mortality (fistula HR 2.60, 95% CI 1.47 to 4.62; stricture HR 2.41, 95% CI 1.86 to 3.11). Although most patients (2133 (72.3%)) had suffered no prior episodes of acute diverticulitis, increasing episodes of acute diverticulitis were associated with an increased risk of developing a fistula (two or more prior episodes, OR 1.54 95%, CI 1.08 to 2.19), but there was no clear relationship with stricture or perforation/abscess.

Conclusions: Although most patients have experienced no prior episodes of acute diverticulitis, fistula formation is preceded by bouts of inflammation. Excess 1-year mortality across the spectrum of CCDD compared with the general population is substantial.