Acute Health Care Utilization of Patients with Mild and Moderate Anemia, Role of Chronic Diseases: A Retrospective Study
Authors: Anne Krishna Kishore , Gvajaia Ani , Albuja Altamirano Maria Fernanda , Choi Eunhee , Imeh Michael , Galicia Garcia Gabriela , Javaid Fazeel , Soe May Hnin Pwint , Oh Jaha , Mazhude Tawana , Pius Ruth , Cuello-Ramirez Alejandrina , Hernandez Aurelia Maria , Altonen Brian , Menon Vidya 
Published: December 2024

Anemia is one of the most common diagnoses in day-to-day practice. It is known that anemia is associated with increased morbidity and mortality in patients with chronic comorbidities, however the association of severe anemia with health care utilization and adverse outcomes have been previously established.
Methods
Here is an IRB-approved Retrospective study that we did to investigate healthcare utilization comprising hospital Emergency Department (ED) visits and Inpatient (IP) admissions over 12 months in patients discharged from Lincoln Medical Center between Jan 1, 2022 - May 15, 2022. A Retrospective chart review of 2410 patients was performed, where 796 of them with severe anemia, active cancer, blood diathesis, or &lt; 24-hour stays were excluded. The remaining 1,614 patients were categorized into control, mild, and moderate anemia groups, based on the hemoglobin level on discharge comprising 851, 418, and 345 patients, respectively. Patients in all cohorts are further divided into 2 groups based on the Charlson Comorbidity Index (CCI) with &lt;3 and 3 & above to compare the association of chronic diseases with healthcare utilization in each cohort. Kaplan Meier graphs were plotted based on the chronic diseases used in the Charleston comorbidity index. Mild anemia was defined as a hemoglobin level between 10 and 11.9 g/dL and moderate anemia between 7 and 9.9 g/dL.
Results:
Comparing the health care utilization with baseline patient characteristics using ANOVA test between the 3 cohorts, IP admissions alone at 1(p&lt;0.001), 3(p&lt;0.001), 6 (p=0.011), & 12(p&lt;0.001) month periods showed increased readmission rates with a mean of 1.325, 1.124, & 0.771 at 12-month period in moderate, mild and control cohorts respectively.To compare the role of change in hemoglobin, the patients were further divided into 4 groups based on their Hemoglobin change as an increase in Hemoglobin of 0-25% and &gt;25% from baseline and decrease of hemoglobin by 0-25% and &gt;25% from baseline. An increase in IP admissions was noted in patients with a hemoglobin drop of &gt;25% (p&lt;0&lt;0.001) from baseline compared to other groups. When comparing respective to the CCI score using the Combined ED and IP visits at 12 months in the mild anemia group, patients with high CCI scores showed increased visits (p&lt;0.001) with a mean of 5.141 compared to 3.167 in low CCI group whereas in the moderate anemia group, patients with low CCI score showed increased visits with a mean of 4.182 when compared to the mean of 3.613 in high CCI group (p&lt;0.001). Similar kind of association is seen when comparing the IP visits along a 12 months in the mild anemia group, patients with high CCI score showed increased visits (p&lt;0.001) with a mean of 1.633 compared to 1.076 in low CCI group where as in the moderate anemia group, patients with low CCI score showed increased visits with a mean of 1.354 when compared to the mean of 2.243 in high CCI group (p&lt;0.001). [VM5] The Pearson Chi-square analysis was run on the groups to see which comorbidities have a significant association with health care utilization in 12 months comprising combined ER and IP visits, chronic diseases like Hypertension, Coronary artery Disease, Congestive heart failure, Peripheral vascular disease, chronic kidney disease (CKD), End Stage Renal Disease (ESRD), Cirrhosis, Peptic ulcer disease, cancer, and HIV had p&lt;0.05, with ESRD and CKD having the strongest association.Kaplan Meier graphs were plotted to evaluate the overall survival rate between the patients with each chronic disease in all cohorts and a Survival difference was noted in Diabetes, Hypertension, Coronary artery Disease, Congestive heart failure, CKD, and ESRD had a P&lt;0.05 with high event rates in moderate anemia group.
Conclusion
In this retrospective study the rates of readmission (ER/IP visits) in patients with mild and moderate anemia were increased when compared to controls. Based on this analysis we establish that moderate anemia patients require more follow up visits as severe anemia patients due to increased health care utilization and poor survival outcomes.