Rectal and Anal Ulceration: Analysis of Demographic Trends, Comorbidity Measures, and Outcomes from the National Inpatient Sample Database

Introduction: Rectal and anal ulceration can occur in the setting of benign or malignant process including but not limited to prolonged constipation, inflammatory bowel disease, infection, ischemia, trauma, or cancer. Limited epidemiological data exist on trends in demographic variation, comorbidity measures, and outcomes for hospitalizations with rectal and anal ulceration. Methods: We analyzed the National Inpatient Sample (NIS) database for all hospitalizations with rectal and anal ulceration (ICD-9 code 569.41 and ICD-10 code K62.6 as applicable) as primary or secondary diagnosis during the period from 2012-2018. 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 during the study period was determined using Cochran-Armitage trend test. Results: Between 2012 and 2018, hospitalizations for rectal and anal ulceration increased from 15,480 to 17,460 (P< 0.0001, Figure 1A). During the study period, slight male preponderance was noted except the year 2013 (47.9% male versus 52.1% female, P< 0.0001). Hospitalizations were more common in Caucasians compared to other races (P< 0.0001). Age group 65-84 remained the most affected (P=0.003, Figure 1B). South remained the most affected region (P=0.0003) throughout the study period. A proportional decrease in hospitalizations was seen at both, urban non-teaching (39.8% to 19.9%, P< 0.0001, Figure 1C) and rural hospitals (5.7% to 4.0%, P< 0.0001, Figure 1C), while the number increased at urban teaching hospitals (54.5% to 76.1%, P< 0.0001, Figure 1C). Mean length of hospital stay ranged from 9.9 ± 0.3 to 10.5 ± 0.3 days (P=0.43). Overall mortality ranged from 3.5% to 4.8% (P< 0.0001, Figure 1D). Some of the most associated comorbid conditions with rectal and anal ulceration were hypertension, fluid and electrolyte disorders, anemias, renal failure, chronic pulmonary disease, and weight loss. Conclusion: During the study period, a nationwide increase in the number of hospitalizations with rectal and anal ulceration was noted. Generally, male gender, Caucasian race, and age group 65-84 remained at the highest risk. Interesting regional demographic, hospital setting, and mortality trends were seen. Further studies are needed to identify potential predictors, and factors responsible for such results, to better elucidate our findings.Figure 1.: Study population and results.