BackgroundThe study of regional variations in surgical outcomes and cost has been used to identify areas for improvement and savings. This study investigates potential regional differences in the outcomes and cost of adult appendicitis. We hypothesized that there would be no difference in rates of laparoscopy, perforation, morbidity, length of stay (LOS), and cost among different regions of the United States. Materials and methodsData were obtained from the California (CA), New York (NY), and Florida (FL) State Inpatient Databases from 2005-2011. Patients between the ages of 18-69 who underwent nonincidental appendectomy in the three different states were evaluated with hierarchical and multivariate negative binomial regression analyses. Primary outcomes included laparoscopy, perforation, negative appendectomy, morbidity, LOS, and cost. ResultsThere were 371,354 appendectomies performed. Multivariate analysis revealed multiple regional differences. Patients in FL were most likely to get laparoscopy (P < 0.01). CA had higher rates of perforation than NY (P < 0.01) and FL (P < 0.05). CA also had higher rates of negative appendectomy compared to both NY and FL (P < 0.01). Morbidity was lower in NY compared to CA and FL (P < 0.01). The LOS was shortest in CA (P < 0.01), despite CA having the highest median per patient cost (P < 0.01). ConclusionsSignificant regional variations do exist with CA having the highest rate of perforation and negative appendectomy. Patients in CA also incurred the highest overall costs. A better understanding of the factors that drive these variations will help improve outcomes and lower cost across all states.