ObGyn Case-mix vs. Medical Complexity: Exploring Patterns in DRG Coding

The paper presents the results of exploratory statistical analysis conducted on eight-month Diagnosis-Related Groups (DRG) reported data from two university clinics of obstetrics-gynecology in Timisoara (3271 records in total). The information included in the analysis consisted of the DRG code, length of hospital stays, the ICD-10 code for the principal diagnosis, and the Case-Mix Index (CMI) values. Although there seemed to be statistically significant differences in length of hospital stay and CMI values between the two clinics (4.33 +/- 3.75 vs. 3.59 +/- 2.51 for hospitalization; and 0.85 +/- 0.01 vs. 0.81 +/- 0.01 for CMI values), these differences did not sustain a closer scrutiny for a substantial, medically meaningful interpretation. They were rather due to the medical complexity of exceptional cases treated in one of the clinics (OG1) during the analyzed period. For grasping the patterns in coding characteristics, more variables should be taken into the analysis, e. g. secondary diagnosis codes and the balance between the incentives for higher CMI values vs. healthcare quality indicators.