Epidemiology of Lower GI Bleed in the United States - An Update From the National Inpatient Survey 2005-2014

Abstract

Introduction: Acute lower gastrointestinal bleeding (LGIB) is a frequent cause of hospitalization and is associated with inpatient morbidity and mortality. There is a scarcity of data on LGIB-related hospitalization trends on a national scale, thus we aimed to study the temporal trends in patient demographics and healthcare utilization using the nationally representative Nationwide Inpatient Survey (NIS). Methods: A retrospective cohort study of LGIB adult patients from the NIS, admitted non-electively from 2005 to 2014, excluding cases with missing data on age/gender/inpatient mortality. We extracted LGIB discharges, using ICD-9-CM codes, defined as follows: LGIB as a primary diagnosis or LGIB sources (e.g., polyps) as secondary diagnoses with a concomitant primary diagnosis of LGIB. Hospitalization Costs (HC) were inflation-adjusted. Ten-year trends for categorical, continuous variables and length of stay (LOS), were analyzed by adjusting for hospital/region variation using mixed-effects models of logistic, linear and accelerated-failure time regression models, respectively. NIS weights yielded national estimates in all analyses. Results: We analyzed 1,526,829 patients admitted for acute LGIB. Mean age was 72.1 years and 53% women (Table 1). Mean Charlson Comorbidity Index (CCI) was 1.33, inpatient mortality 1.1% and LOS 4.3 days (median=3). Mean HC were $9,385±44. Colonoscopy rate was 61.4%. Over the study period, the most common bleeding sources were diverticulosis (47.5%; decreasing trend p<0.001), colorectal polyps (20.4%; increasing trend p<0.001) and hemorrhoids (16.9%; increasing trend p<0.001). The prevalence of LGIB admissions is increasing (p-trend<0.001), while colonoscopy rates have been decreasing (Fig 1A; p-trend<0.001). White patients have been decreasing, while Blacks and Hispanics increasing (Fig 1C; all p-trend<0.001). Of note, CCI has been increasing (Fig 1B; p-trend<0.001), yet inpatient mortality has been decreasing (Fig 1D; p-trend<0.001). HC remained stable (p-trend=0.336), while LOS has been decreasing (p-trend<0.001). Aggregate HC increased from $1.3 billion to $1.4 billion (p-trend<0.001).559_A Figure 1. Baseline CharacteristicsConclusion: The LGIB burden has been increasing in the last decade with improvement in inpatient mortality, shorter LOS, and stable hospitalization costs, while colonoscopy rates have been slowly decreasing. The aggregate cost burden remains increasingly high. Patients present increasingly more comorbid, while the non-white fraction is increasing.559_B Figure 2. Trends