Temporal Trends in the Incidence and Natural History of Diverticulitis: A Population-Based Study

Abstract

Objectives: Data on the incidence and natural history of diverticulitis are largely hospital-based and exclude the majority of diverticulitis patients, who are treated in an outpatient setting for uncomplicated diverticulitis. We assessed temporal trends in the epidemiology of diverticulitis in the general population.

Methods: Through the Rochester Epidemiology Project we reviewed the records of all individuals with a diagnosis of diverticulitis from 1980 to 2007 in Olmsted County, Minnesota, USA.

Results: In 1980-1989, the incidence of diverticulitis was 115/100,000 person-years, which increased to 188/100,000 in 2000-2007 (P<0.001). Incidence increased with age (P<0.001); however, the temporal increase was greater in younger people (P<0.001). Ten years after the index and second diverticulitis episodes, 22% and 55% had a recurrence, respectively. This recurrence rate was greater in younger people (hazard ratio (HR) per decade 0.63; 95% confidence interval (CI), 0.59-0.66) and women (HR 0.68; 95% CI, 0.58-0.80). Complications were seen in 12%; this rate did not change over time. Recurrent diverticulitis was associated with a decreased risk of complications (P<0.001). Age was associated with increased risk of local (odds ratio (OR) 1.27 per decade; 95% CI, 1.04-1.57) and systemic (OR 1.83; 95% CI, 1.20-2.80) complications. Survival after diverticulitis was lower in older people (P<0.001) and men (P<0.001) and worsened over time (P<0.001). The incidence of surgery for diverticulitis did not change from 1980 to 2007.

Conclusions: The incidence of diverticulitis has increased by 50% in 2000-2007 compared with 1990-1999, and more so in younger people. Complications are relatively uncommon. Recurrent diverticulitis is frequent but typically uncomplicated. Younger people with diverticulitis have less severe disease, more recurrence, and better survival.

Figure 1

Age- and Sex-Adjusted Annual Incidence of Diverticulitis in Olmsted County, Minnesota, 1980–2007.

Figure 2

Relation Between Age and Incidence of Diverticulitis in Olmsted County, Minnesota, 1980–1989 and 2000–2007. The separation between the curves was greater for the 2000–2007 period and the earlier epochs in younger people, which reflects a more prominent increase in incidence over time. Ln indicates the natural logarithm of incidence rate of diverticulitis per 100,000 person-years.

Figure 3

Temporal Trends in Radiologic Diagnosis of Diverticulitis, 1997–2007. The proportion of patients in whom computed tomography (CT)-documented diverticulitis increased significantly over time.

Figure 4

Kaplan-Meier Estimates of Cumulative Risk of Recurrent Diverticulitis.

Figure 5

Risks of Recurrence and Complication in Diverticulitis. A) Risk of recurrent diverticulitis after complicated diverticulitis. B) Risk of complicated diverticulitis after recurrent diverticulitis.