Technical / HSCIC tool shines light on HRG grouping

 They are assigned on the basis of codes covering procedures (OPCS) and diagnoses (ICD10). There are tens of thousands of these codes with some 16 million finished consultant episodes for admitted care each year needing to be assigned an HRG. So it is a good job the grouping process is automated, with software groupers developed and provided by the National Casemix Office at the Health and Social Care Information Centre.

But what happens if you need to understand the grouping process in more detail? How do you investigate if changed grouping logic is behind a shift in individual HRG costs rather than changes in clinical practice or costing?

The answer is a ‘code to group’ tool, published each year by the HSCIC to enable practitioners manually to explore the grouping process. The latest version, which documents the logic used in the 2014/15 reference cost grouper, was published earlier this year (www.hscic.gov.uk/casemix/costing).

The ‘code to group’ tool looks complicated at first glance, covering 17 separate spreadsheets. Six ‘look-up tables’ cover basics such as lists of HRG chapters, sub-chapters, HRGs and the underpinning diagnosis and procedure codes. Nine worksheets provide reference lists with information on flags, hierarchies and comorbidity lists (all key to correct grouping). But the main components are the ‘code to group’ and ‘group to split’ worksheets.

The ‘code to group’ worksheet allows users to determine the HRG root for a code (dominant procedure or primary diagnosis, say) from an FCE/spell. The ‘group to split’ worksheet allows the specific HRG to be determined based on conditions being met by the FCE spell, as defined by flags.

Walkthrough examples, set out in the guidance, help the user to get to grips with the tool. For example, consider a patient whose record shows one procedure and one diagnosis code as shown in figure 1.

Step 1 Look up the OPCS procedure code D084 (procedure code for incision of external auditory canal) in the hierarchy list. Procedure hierarchies provide a way of comparing the relative complexity of procedures across HRG chapters. Each procedure has an associated value between 0 and 40, reflecting rising resource intensity. Procedures scored from 5 to 40 can be used for grouping, so as long as the procedure has a hierarchy value in this range, you can proceed. In this case, the value is 12.

Step 2 Select D084 in the code to group worksheet. This indicates a single HRG root – CA55 – with a flag ‘Los 0 to 1’. In this case, it is obvious what the condition is for this root HRG to be correct – and the patient meets the criteria with a length of stay of one day – and so the HRG root has been determined. In other cases the flag can be looked up in the documentation list to find out the necessary criteria and this can be checked with the patient record.

Step 3 On the ‘group to split’ worksheet, select the HRG root. This suggests two potential HRG splits, each identified by different flags. Working from right to left, each flag should be looked up in the documentation flag worksheet until the specific patient details meet the flag criteria described. In this case the first HRG split has a flag of ‘p’ – the flag for 18 years or under – and so the HRG split has been determined as CA55B.

Looking up this HRG in the HRG worksheet reveals the HRG to be Minimal ear procedures within the ear, nose, mouth, throat and neck procedures sub-chapter.

More complex examples in the guidance involve complications and comorbidities and primary diagnosis qualifiers. This may be too much detail for some. But the tool provides a powerful way to unlock the grouping process.

Figure 1

Likely survey questions