Table 2.
Overview of the evolution of the English HRG system
| 1st DRG version | 2nd DRG version | 3rd DRG version | 4th DRG version | 5th DRG version | 6th DRG version | |
|---|---|---|---|---|---|---|
| Date of introduction | May 1992 | August 1994 | June 1997 | October 2003 | October 2006 | Phase 1: April 2013 |
| (Main) Purpose | Patient classification | Patient classification | Patient classification | Patient classification, reimbursement | Patient classification, reimbursement | Patient classification, reimbursement |
| DRG system | HRG1 | HRG2 | HRG3.1 | HRG3.5 | HRG4 | HRG4+ |
| Cost and/or performance data used for development | Adaptation of United States DRGs | Data analysis of groupings | Clinical review to refine for ICD-10. Statistical analysis | Clinical Working Groups refined categories. | Expert working groups’ | Expert working groups, clinical communities, as well as international casemix developments and best practice* |
| micro-costing data | ||||||
| Statistical analysis | ||||||
| Number of DRGs | 534 | 533 | 572 | 610 | Updated annually: | Updated annually: |
| 1389 (2006/7) to 1657 (2011/12) | 2100 | |||||
| Applied to | Public hospitals | Public hospitals | Public hospitals | Public hospitals/private hospitals or treatment centres treating NHS patients | Public hospitals/private hospitals or treatment centres treating NHS patients | Public/private hospitals or treatment centres treating NHS patients |
| Acute admissions | Acute admissions | Acute admissions | Acute admissions | Acute admissions | Acute admissions | |
| Outpatients | Outpatients | |||||
| Critical Care | Accident and Emergency | |||||
| Critical Care |
*Developed in partnership with the clinical community, as represented and endorsed by the Royal Colleges Associations and Professional Bodies. The increased applicability of the Casemix classification to emerging policy requirements has been influenced by findings from the Department of Health's International Review of Classifications, as well as international casemix developments and best practice
Sources: Anthony, 1993 [2]; Benton, 1998 [3]; Casemix Design Authority, 2009 [4]; NHS Information Centre for Health and Social Care, 2008 [5]; Information Standards Board for Health and Social Care, 2009 [6]; National Casemix Office, 2013 [7]; National Casemix Office, 2014 [35]