Impact of Ascites on Morbidity and Length of Hospital Stay: A Large Retrospective Study from a Tertiary Referral Center.

Background and

Objectives

Ascites is associated with substantial symptom burden and increased healthcare utilization, and it is observed in patients with advanced disease across multiple etiologies. However, because ascites is a clinical sign rather than a diagnosis category, it can be challenging to study using routine health reporting. In routinely collected hospital administrative data, ascites is commonly captured using International Classification of Diseases, Tenth Revision (ICD-10) code R18, an etiologically non-specific classification whose outcome implications are less documented. We aimed to evaluate the incremental association of R18-coded ascites with length of stay (LOS), readmission burden, and in-hospital mortality in the Gastroenterology and Internal Medicine inpatient department, beyond comorbidity burden and other coded decompensation proxies. Materials and

Methods

We conducted a single-center retrospective study using routinely collected administrative discharge data from adult inpatient admissions (2015-2023) in the Gastroenterology and Internal Medicine department of a Romanian tertiary-care hospital. Admissions were classified by the presence of ICD-10 R18-coded ascites. Outcomes were LOS, readmission burden (count of subsequent admissions), and in-hospital mortality. Multivariable models adjusted for age, sex, and comorbidity burden (Charlson Comorbidity Index), with additional models incorporating ICD-10-derived decompensation proxies to assess overlap in administrative severity signal. LOS was further examined within Charlson strata to evaluate incremental stratification.

Results

Coded ascites was associated with higher hospital burden, including longer LOS and greater readmission burden, and with higher in-hospital mortality in partially adjusted models. Within each CCI stratum, LOS remained higher among admissions with R18-coded ascites, supporting incremental stratification beyond comorbidity alone. Furthermore, mobility impairment was an important predictor of LOS. Age-stratified analyses suggested a high-burden phenotype among younger patients and infrequent R18 coding among the very elderly in this cohort.

Conclusions

These findings support the potential utility of R18-coded ascites as a pragmatic administrative marker for risk adjustment and service planning.