Seasonal and weekly patterns of hospital admissions for acute diverticulitis

OBJECTIVE: Onset and hospitalization of acute diseases do not occur randomly, but exhibit preferred high-risk temporal periods. The aim of this study, based on the database of hospital admissions of the Emilia-Romagna region of Italy, was to evaluate the possible existence of a seasonal or weekly pattern of hospitalization for acute diverticulitis (AD), and different rates of complications between weekend (WE) vs. weekday (WD) admissions. PATIENTS AND METHODS: The study included all emergency hospital admissions in Emilia Romagna Region for AD between 1999 and 2011 (ICD-9-CM codes: 562.11-562.13). Day of admission was categorized, respectively, into four 3-month intervals, twelve 1-month intervals, seven 1-day intervals for statistical analysis, performed by c2 test goodness of fit and partial Fourier series on total number of cases, males and females, nonfatal or fatal cases, without and with hemorrhage. RESULTS: The database contained records of 29,428 events of AD, relative to 24,843 different patients (mean age: 71.2±13.8 years; 40.5% males). Chronobiological analysis yielded a biphasic rhythmic pattern in AD admissions, characterized by two peaks in Autumn and Spring. As for day of admission, a progressive decrease of frequency during the week was observed. In turn, a slight increase of admissions on WE was observed for hemorrhagic events. CONCLUSIONS: An excess burden of hospitalization for AD is observed in the region Emilia-Romagna of Italy, with demonstration of a biphasic cyclical pattern with peaks in Autumn and Spring. Again, a decreasing number of Monday to Friday admissions was observed. Further studies are needed to identify possible underlying causes.