Colonic Diverticulosis and Uncomplicated Diverticulitis Are Associated With a Lower Not Higher Risk of Mortality When Confounding Factors Are Held Constant

Background and Aim

The association between colonic diverticulosis, diverticulitis, and mortality is controversial. This study evaluated the association between diverticular disease and mortality over a prolonged period in a GP cohort.

Methods

GP records were sourced from the United Kingdom medical database (THIN). Diverticulosis and diverticulitis were identified via Read codes. The overall patient cohort (n = 1 274 260) included patients with colonic diverticula (n = 39 521 [3.1%], mean age 54) and no diverticula (control group) (n = 1 234 739 [96.9%], mean age 38). Poisson regression estimated relative rates, and durational time at risk and survival probability were calculated.

Results

Colonic diverticula are associated with an increased mortality risk when compared with nondiverticular patients (OR = 1.89, 95% CI 1.84–1.94; p < 0.001). However, controlling for age, sex, and potential confounding variables yielded a decreased mortality risk overall for colonic diverticula patients (HR = 0.66, 95% 0.64–0.6; p < 0.001). When the diverticulitis cohort is separated into uncomplicated and complicated, increased mortality is observed in both uncomplicated diverticulitis (HR = 0.64, 95% CI 0.61–0.66; p < 0.001) and complicated diverticulitis (HR = 1.14, 95% CI 1.02–1.28; p = 0.024), but on controlling for confounding, there is a decreased risk of mortality for uncomplicated diverticulitis (HR = 0.65, 95% CI 0.63–0.66; p < 0.001) but almost two times increased mortality risk for complicated diverticulitis (HR = 1.18, 95% CI 1.05–1.32; p = 0.006).

Conclusions

In this large UK GP sample, controlling for age, sex, and comorbidities, patients with uncomplicated diverticula are associated with a lower mortality risk. However, complicated diverticulitis still carries two times the risk of mortality than those with no or uncomplicated colonic diverticula.