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Henry Ford Hospital


Introduction: Sphincter of Oddi plays an important physiologic role by controlling the flow of biliary and pancreatic secretions through the ampulla of Vater into the duodenum. Sphincter of Oddi dysfunction (SOD), either from stenosis or dyskinesis, has been associated with complications such as biliary pain, idiopathic recurrent pancreatitis, and post-ERCP pancreatitis. Limited epidemiological data exists on the number of hospitalizations, demographic variations, cost of care, and comorbidity measures associated with SOD.Methods: We analyzed the National Inpatient Sample (NIS) database for all hospitalizations with SOD (ICD-9 code 576.5) as primary or secondary diagnosis during the period from 2005-2011. NIS is the largest all-payer inpatient care database in the United States, containing data on more than 7 million hospital stays. Its large sample size is ideal for developing national and regional estimates. Statistical significance of variation in hospitalizations, patient demographics, comorbidity measures, and cost of care during the study period were determined using Cochran-Armitage trend test.Results: Between 2005 and 2011, hospitalizations with SOD increased from 600 to 980 (p<0.0001, figure 1A). SOD remained more common in women (p=0.01) and Caucasians (p=0.11), trends of which only showed an increase through the study period. Although age group 35-49 remained the most commonly affected, age group 18-34 showed the greatest rise from 15.5% to 25.9% (p<0.0001). There was a significant increase in the number of hospitalizations with SOD in the Midwest which superseded the South to become the most commonly affected region by 2011 (p<0.0001, figure 1B). From 2005 to 2011, the number of hospitalizations with SOD in urban teaching hospitals increased from 38.9% to 49.7% (p<0.0001, figure 1C) whereas urban non-teaching (45.2% to 37.8%, p<0.01, figure 1C) and rural (15.9% to 12.1%, p<0.0001, figure 1C) hospitals experienced an overall decline. Although length of stay did not show a significant variation, ranging between 4.1 and 5.1 days (p=0.53), cost of care associated with SOD hospitalizations did show an overall upward trend, ranging between $8,089 and $10,770 (adjusted for inflation, p<0.0001, figure 1D). Hypertension, renal failure, chronic pulmonary disease, psychiatric disorders and anemia remained some of the most commonly associated comorbidities. Interestingly, over the study period psychiatric disorders superseded renal failure and chronic pulmonary disease to be more commonly associated with SOD (p<0.0001, figure 2).Conclusion: A significant rise in the number of SOD related hospitalizations, with changing trends in demographic variations, cost of care and associated comorbidities, was seen during the study period. Further studies are needed to identify factors responsible for such trends to better elucidate our findings.

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Changing Trends in US Hospitalizations with Sphincter of Oddi Dysfunction: Insights from the National Inpatient Sample Database