More Colonoscopies, but at What Cost? Determinants of Healthcare Utilization for Patients Requiring Inpatient Colonoscopy

Introduction: Colonoscopy has become one of the most widely utilized diagnostic and therapeutic procedures in America, with approximately 19 million performed annually. As the number of inpatient colonoscopies is on the rise, there is poor understanding of the effects on healthcare utilization. The aim of this study was to determine individual and hospital-related factors which play a role in total length of stay (LOS) and overall cost of inpatient colonoscopy. Methods: Data from the nationwide inpatient sample from 2016 to 2017 were used, which included 108,245 cases. The tenth version of the International Classification of Disease coding system (ICD10) was used for patient selection. We included demographic characteristics with a primary focus on independent variables affecting LOS and overall cost for patients requiring inpatient colonoscopy. The panel data was analyzed using hospital fixed-effects regression models to account for unobserved, time-invariant hospital characteristics. Results: The majority of the hospitals conducting inpatient colonoscopies in our sample period were large, urban, not-for-profit teaching hospitals. The average age of patients was 65 years with a largely female (52%), White (66%), low median household income (31%) and Medicare insured (60%) predominance. Female patients were found to have a shorter LOS compared to males (β = -0.3618, P < 0.05) as well as lower total cost (β = -4339.00, P < 0.05). Total hospital charges decreased with increasing patient age (β = -202.38, P < 0.05). Patients of Black (β = 0.2540, P < 0.05) and Native American races (β = 1.0265, P < 0.05) had longer LOS compared to those who are White. Among the included indications for colonoscopy, patients with inflammatory bowel disease, radiologic evidence of colitis, hematochezia and melena, and irritable bowel syndrome had both shorter LOS and lower overall cost. Patients with documented history of cerebrovascular accident had longer LOS after inpatient colonoscopy. Finally, comorbid conditions associated with higher total charges included chronic anticoagulation use, type 2 diabetes mellitus, obesity, and hypertension. Conclusion: The burden to healthcare utilization for patients undergoing inpatient colonoscopy remains largely variable amongst multiple patient etiologies. With the expanding need for inpatient colonoscopies, further studies are needed to evaluate the timing of colonoscopy with regards to patient characteristics and its impact on length of stay and overall hospitalization cost.Table 1.: Demographic characteristics and inpatient outcomes in oncologic patients with and without CDI in 2015-2017 in the US