Related Experiment Video
Updated: Feb 6, 2026
Hydra, a Computer-Based Platform for Aiding Clinicians in Cardiovascular Analysis and Diagnosis
Published on: September 26, 2018
A review of the complexity adjustment in the Korean Diagnosis-Related Group (KDRG)
Sujeong Kim1, Chaiyoung Jung1, Junheum Yon2
1The Catholic University, Korea.
Insights
The Korean Diagnosis-Related Groups (KDRG) Complication and Comorbidity Level (CCL) shows poor performance in reflecting healthcare costs. Revisions are needed to ensure accurate reimbursement and reflect the current Korean healthcare system.
Area of Science:
- Health Services Research
- Health Economics
- Medical Coding Systems
Background:
- The Korean Diagnosis-Related Groups (KDRG) system, revised in 2003, modified the complexity adjustment mechanism from the Australian Refined Diagnosis-Related Groups (AR-DRGs).
- A 2014 review indicated the Complication and Comorbidity Level (CCL) within the AR-DRG system had a weak correlation with actual healthcare costs.
Purpose of the Study:
- To review the Complication and Comorbidity Level (CCL) for KDRG version 3.4, drawing on Australian experiences.
- To assess the performance of the CCL in reflecting patient complexity and associated hospital charges within the Korean healthcare system.
Main Methods:
- Analysis of inpatient claim data from 2011, selecting 5,731,551 episodes with no or minimal complications and comorbidities (CC).
- Utilized analysis of variance (ANOVA) and Duncan's test to compare average hospital charges across different CCLs within Adjacent Diagnosis-Related Groups (ADRGs).
- Categorized ADRGs into VALID, PARTIALLY VALID, and NOT VALID based on how well CCL reflected complexity and charges, using R-squared (R²) values.
Main Results:
- Out of 600 analyzed ADRGs, 114 (19.03%) were VALID, 190 (31.72%) were PARTIALLY VALID, and 295 (49.25%) were NOT VALID.
- The average R² for hospital charges related to CCL was low at 4.94%.
- The average R² values for VALID, PARTIALLY VALID, and NOT VALID categories were 4.54%, 5.21%, and 4.93%, respectively, indicating inconsistent performance.
Conclusions:
- The CCL, as a primary method for complexity adjustment using secondary diagnoses, demonstrated low performance in the KDRG system.
- Re-evaluation of secondary diagnoses as a complexity indicator is recommended once accurate coding and cost data become available.
- Outdated CC lists and levels in the KDRG system necessitate updates to align with the current Korean healthcare landscape, emphasizing the need for reliable cost data and accurate coding for reimbursement accuracy.
Background:
The Korean Diagnosis-Related Groups (KDRG) was revised in 2003, modifying the complexity adjustment mechanism of the Australian Refined Diagnosis-Related Groups (AR-DRGs). In 2014, the Complication and Comorbidity Level (CCL) of the existing AR-DRG system was found to have very little correlation with cost.
Objective:
Based on the Australian experience, the CCL for KDRG version 3.4 was reviewed.
Method:
Inpatient claim data for 2011 were used in this study. About 5,731,551 episodes, which had one or no complication and comorbidity (CC) and met the inclusion criteria, were selected. The differences of average hospital charges by the CCL were analysed in each Adjacent Diagnosis-Related Group (ADRG) using analysis of variance followed by Duncan's test. The patterns of differences were presented with R 2 in three patterns: The CCL reflected the complexity well (VALID); the average charge of CCL 2, 3, 4 was greater than CCL 0 (PARTIALLY VALID); the CCL did not reflect the complexity (NOT VALID).
Results:
A total of 114 (19.03%), 190 (31.72%) and 295 (49.25%) ADRGs were included in VALID, PARTIALLY VALID and NOT VALID, respectively. The average R 2 for hospital charge of CCL was 4.94%. The average R 2 in VALID, PARTIALLY VALID and NOT VALID was 4.54%, 5.21%, and 4.93%, respectively.
Conclusion:
The CCL, the first step of complexity adjustment using secondary diagnoses, exhibited low performance. If highly accurate coding data and cost data become available, the performance of secondary diagnosis as a variable to reflect the case complexity should be re-evaluated.
Implications:
Lack of reviewing the complexity adjustment mechanism of the KDRG since 2003 has resulted in outdated CC lists and levels that no longer reflect the current Korean healthcare system. Reliable cost data (vs. charge) and accurate coding are essential for accuracy of reimbursement.
Related Concept Videos
01:10Review and Preview
Percentiles are a type of fractile that partition data into...
01:13Review and Preview
01:25The Anchoring-and-Adjustment Heuristic
01:12Adjusting a Traverse
01:11Renal Failure: Dose Adjustments
Reduced renal clearance and elimination rate are common outcomes of renal impairment. These alterations lead to a prolonged elimination half-life and an altered apparent volume of distribution for drugs. As a result, dosage adjustments are typically necessary to maintain optimal drug levels in the body.
However, dosage adjustments...
01:22Nursing Diagnosis
The nursing diagnosis focuses on evidence-based...