ISSN: 2222-6990
Open access
The Case Mix Index (CMI) is a cornerstone metric in healthcare, quantifying patient complexity and resource intensity, with direct implications for hospital reimbursement and operational performance. Despite its importance, CMI and related financial metrics are not typically included in the specialty training or competency frameworks of healthcare professionals, particularly physicians, limiting their ability to align clinical practices with institutional objectives. This study highlights the foundational role of the Diagnosis-Related Group (DRG) system in CMI calculation and demonstrates how accurate documentation and coding effectively capture patient complexity. The research integrates quality improvement methodologies, such as the Plan-Do-Study-Act (PDSA) cycle, to drive CMI optimization. For instance, targeted interventions, including real-time documentation reviews, multidisciplinary team collaboration, and CDI specialist engagement, are shown to increase documentation accuracy and DRG alignment. It is critical for healthcare professionals to learn how CMI is calculated to understand the metrics fully, respond effectively, and implement improvements that reflect the true complexity of patient care. The study provides a structured framework that combines CDI programs, AI-driven technologies, and quality improvement methodologies, empowering healthcare professionals to address documentation gaps and enhance operational efficiency. By bridging this knowledge gap, the research emphasizes that optimizing CMI is not only an administrative task but a strategic imperative for achieving clinical excellence, value-based care, and financial sustainability.
ACDIS White Paper. (2022). Demystifying and communicating case-mix index. Simplify Compliance LLC.
Adonis Content Team. (2024, February). Case Mix Index (CMI) explained: Its impact in healthcare. https://www.adonis.io/resources/case-mix-index-cmi-explained-its-impact-in-healthcare
Apathy, N. C., Holmgren, A. J., & Cross, D. A. (2024). Physician EHR time and visit volume following adoption of Team-Based Documentation support. JAMA Internal Medicine, 184(10), 1212. https://doi.org/10.1001/jamainternmed.2024.4123
Böcking, W., & Trojanus, D. (2008). Diagnosis Related Groups (DRGs). In Springer eBooks (pp. 263–265). https://doi.org/10.1007/978-1-4020-5614-7_790
Boes, S., Schmid, C., & Brach, M. (2021). The economics of DRGs in modern healthcare systems. Health Economics Journal, 23(4), 233-248.
CMS. (2022). What is the CMS National Quality Strategy? Retrieved from CMS Website.
Dubai Health Authority. (2015). Dubai Health Insurance Major Diagnostic Categories - 2014 Overview and comparison. https://www.isahd.ae/content/docs/2nd%20Report%20-%20Major%20Diagnostic%20Categories,%202014.pdf
HCPro. (2022). Demystifying and communicating case-mix index. https://acdis.org/sites/acdis/files/resources/CR-6483_ACDIS-Advisory%20Board%20CMI-WP_Final.pdf
Hjelm, N., Sanan, A., Gill, K., Sagalow, E., Krein, H., & Heffelfinger, R. (2020). Economic Impact of Facial Plastic and Reconstructive Surgery: The Case Mix Index. Journal of Otorhinolaryngology and Facial Plastic Surgery, 6(1), 1-4. https://doi.org/10.22037/orlfps.v6i1.32937
International Refined-DRGs (IR-DRGs) | 3M UAE. (n.d.). MMM-ext. https://www.3mae.ae/3M/en_AE/health-information-systems-ae/patient-classification-methodologies/ir-drgs/
Ren, S., Yang, L., Du, J., He, M., & Shen, B. (2024). DRGKB: a knowledgebase of worldwide diagnosis-related groups’ practices for comparison, evaluation and knowledge-guided application. Database, 2024. https://doi.org/10.1093/database/baae046
Shamloo, N., & Hjelm, D. (2020). Case mix analysis and implications for DRG reform. Journal of Healthcare Systems Research, 14(3), 15-29.
Yale University. (2019). Design and development of the Diagnosis Related Group (DRG). In PBL-038.https://www.cms.gov/icd10m/version37-fullcode cms/fullcode_cms/Design_and_development_of_the_Diagnosis_Related_Group_(DRGs).pdf
Zheng, X., Xiao, X., Shen, K., Pei, T., Lin, X., Liu, W., ... & Meng, X. (2024). Impact of Diagnosis-Related Groups (DRG) reform on cost homogeneity of treatment for patients with malignant tumors. Scientific Reports, 14(21212). https://doi.org/10.1038/s41598-024-71917-y
Ahmed, A. M., & Almessabi, A. M. (2025). What Every Healthcare Professional should Know About Case Mix Index (CMI): A Guide to Understanding Complexity and Value in Patient Care. International Journal of Academic Research in Business and Social Sciences, 15(1), 1225–1239.
Copyright: © 2025 The Author(s)
Published by HRMARS (www.hrmars.com)
This article is published under the Creative Commons Attribution (CC BY 4.0) license. Anyone may reproduce, distribute, translate and create derivative works of this article (for both commercial and non-commercial purposes), subject to full attribution to the original publication and authors. The full terms of this license may be seen at: http://creativecommons.org/licences/by/4.0/legalcode