Grouping of codes for conditions (RCGs)
Read codes (version 2, Scottish) are the recommended national standard coding system in Scottish general practices for recording clinical information (signs, symptoms, diagnoses or activities). More information on Read codes can be found on the Health and Social Care Information website. Clinicians participating in PTI are asked to code the clinical information as specifically as possible. The number of codes that can be entered per consultation is in theory almost unlimited, but typically only one or two codes will be entered. Nurses are asked to code an activity and an underlying morbidity (the disease or condition that lead to the activity being carried out), whereas GPs are not typically expected to enter an activity. Clinicians only record conditions that are being actively managed within an episode of care. Conditions that a patient has, but which are not a reason for the contact, are not recorded as part of that particular contact. For example, a patient with diabetes who consults because of backache and a cold will have codes recorded for these conditions but not for diabetes.
Read code Groupings (RCGs)
PTI data containing the full range of Read codes can be analysed by combining Read codes for a particular condition into one umbrella grouping. These groupings have the benefit of permitting practitioners to record morbidity using the full richness of Read codes (there are over 80,000 individual codes available), while at the same time facilitating analysis using common, or standard, groupings of morbidity codes.
As part of a larger review of the PTI dataset completed in March 2007, ISD carried out a complete review of the grouping of Read codes as used for analysis (previously called Standard Morbidity Groupings or SMGs). The groupings are broadly based on the chapters of the World Health Organisation International Classification of Diseases(10th revision, ICD-10; ICD-10 is another commonly used coding system, used for example in coding hospital, mortality and cancer registration data in Scotland and elsewhere in the UK & Europe). The groupings now used are referred to as Read code Groupings (RCGs) and were revised to specifically address the following issues:
- Refinement of morbidity groupings to remove non-specific symptoms that do not necessarily define the condition.
- Division of the previous single 'symptoms and signs' category into smaller, more meaningful categories such as respiratory symptoms or psychological symptoms.
- Grouping of activities not previously available.
- Generally, use of categories which directly relate to ICD-10 chapters or parts of chapters.
Although it is now possible to produce PTI analyses based exclusively on Read codes that map to ICD-10 chapters, this would ignore a large quantity of codes covering a host of symptoms, signs, activities and relatively vague (preliminary) diagnoses. Practices continue to record activity codes (such as asthma review) that are likely to indicate a diagnosis (such as asthma) without specifying the condition. While this might not strictly be the correct way to record a clinical diagnosis, excluding such activity codes will result in a misleading exclusion of these consultations, so routine analysis of PTI data includes these codes in the definition of the condition. The full list of Read code groupings is provided in the Excel file PTI_Nov11_RCG_description.xls (55KB).
The Read code groupings are under regular review and limited revisions are carried out each year when also new Read codes are added. Detailed commentary on the impact of such changes is available on the ‘Note of Revisions’ page on the PTI website.