Trends in hospital admission for acute diverticulitis in Italy from 2008 to 2015

Background: Epidemiological studies in Western countries have documented an increase of hospitalizations for acute diverticulitis (AD) but Italian evidence is scarce. The aim of the present study was to analyse the trend in hospitalization for AD, including in-hospital mortality, in Italy from 2008 to 2015. Methods: Through the Italian Hospital Information System of the National Health System, we identified diverticulitis of the colon as a discharge diagnosis. Age- and gender-specific rates of hospitalization for AD were assessed. Results: 174,436 hospitalizations were identified with an increasing rate in 2008–2015 from 39 to 48 per 100,000 inhabitants (p < 0.001). The rate of hospitalization was higher for women, but the increasing trend over time was even more pronounced among men (mean increase per year 3.9% and 2.1% among men and women, respectively) (p < 0.001). The increased rate of hospitalization was accounted for by patients less than 70 years old, especially those under 60. In contrast, the hospitalization rate for older patients (age ≥ 70 years) was higher but remained unchanged during the study period. The number of patients with one hospital admissions was significantly higher than the number of patients with at least two hospitalizations (p < 0.001) and both groups showed a significant and comparable increase year by year. The overall in-hospital mortality rate increased from 1.2 to 1.5% (p = 0.017). More specifically, the increase was observed in patients at their first hospitalization [from 1 to 1.4% (mean increase per year of 3%, p = 0.003)]. An increase in mortality was most evident among women (from 1.4 to 1.8% p = 0.025) and in older patients [age 70–79 years from 1.2 to 1.7% (p = 0.034), ≥ 80 years from 2.9 to 4% (p = 0.001)]. Conclusions: In Italy, between 2008 and 2015, the rate of hospitalization for AD has been constantly increasing due to the hospitalization of younger individuals, especially men. There was a significant increase of in-hospital mortality especially among women, elderly and during the first hospitalization. These findings suggest the need for increased awareness and clinical skills in the management of this common condition.