Major Changes in Thai Diagnosis Related Group Version 6.2

Abstract

Thai Diagnosis Related Group (TDRG) is a patient classification system aiming to classify inpatients with similar clinical severity and hospital resource consumption in the same group. Thailand has used several versions of TDRG as a hospital inpatient payment tool starting with the National Health Security Office, then the Social Security Office and the Comptroller General’s Department, Ministry of Finance respectively. Three public insurance schemes have used TDRG version 5.1 since 2012, therefore TDRG should be updated to reflect new patterns of medical treatment and resource consumption. This paper presents results and major changes of TDRG version 6.2 compared with TDRG version 5.1. Major changes of TDRG version 6.2 comprised initial reclassification methodology by organizing several workshops with experts in many medical specialties exploring diagnosis complexity level in relationships with level of resource use in existing claim data. The iterative meetings with experts achieved higher correlation between evidence-based patient classification and hospital resource consumption. The final recalibration of TDRG version 6.2 adopted the normalization methodology to smoothen the untoward fluctuations of new relative weights (RW). Most statistics results showed better performance of TDRG version 6.2, despite the lower number of disease clusters in TDRG version 6.2 than TDRG version 5.1 (603 vs. 726 DCs), and lower number of DRGs (1,541 vs. 2,451 DRGs, a 910 reduction). TDRG version 6.2 achieved a higher reduction in variance (RIV) on standardized charge than TDRG version 5.1, suggesting that TDRG version 6.1 could classify better than the previous TDRG. In addition, relative weight of TDRG version 6.2 had higher explanatory power on hospital resource use than TDRG version 5.1. Furthermore, the adjusted RW could explain nearly 60% of total hospital resource use. In conclusion, TDRG version 6.2 better classified patients into the same groups with higher correlation to hospital resource use than TDRG version 5.1. The three public insurance schemes should adopt TDRG version 6.2 and determine appropriate base rates to pay for hospital inpatient care according to the adjusted RW of TDRG version 6.2.