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UKCRC Health Research Classification System

Case studies, exemplars or tracer conditions

Advice on health categories

The term ‘case study’ is used in a variety of contexts in biomedicine, such as a clinical case study chronicling the treatment of a single patient. However in this context we use ‘case study’ to describe where patients with a particular condition may be used as a proxy / exemplar / tracer condition in studies evaluating models, services or systems that are applicable to other (or a wider range of) conditions.

In these circumstances the specific condition used in the patient group (the ‘case study’) may not be the main aim of carrying out the study, but is used purely to demonstrate a broader argument. Therefore in this specific context the appropriate health category for the condition used as the case study may not be relevant to this wider study aim.

e.g. If the study examines prescriptions for a specified condition, but the wider aim is to assess prescriptions across all areas of health or wellbeing, it would may be more appropriate to ignore the exemplar condition and use the Generic Health Relevance health category instead.

However in many cases the health category of the case study / proxy / exemplar / tracer condition will still be intrinsically linked to the wider study being addressed. In this case, dual coding of both example condition and wider topic would be appropriate.

e.g. Asthma is routinely coded as Respiratory in HRCS, but if it is used as an example of allergenic reactions, it would be appropriate to add the Inflammatory & Immune System health category to the coding of the project.

This approach of when to apply dual coding is similar to the approach taken when considering sequelae (one disease as a consequent of another), studies of cachexia and in co-morbidity research.


Main inclusion criteria

  • Research applicable to all diseases and conditions or to general health and well-being of individuals.
  • Public health research, epidemiology and health services research that is not focused on specific conditions.
  • Underpinning biological, psychosocial, economic or methodological studies that are not specific to individual diseases or conditions.


Advice on health categories

There are four main circumstances where the Generic Health Relevance category is most applicable:

  1. Research that is relevant to all diseases and conditions or to general health and well-being.
  2. Any research that cannot be attributed to a particular disease or condition or to normal function of a specific type of cell or system, defined by the top 19 health categories.
  3. If research is judged relevant to more than five Health Categories then these should be substituted for 100% Generic Health Relevance.
  4. As an additional code for studies with a disease(s)/condition(s) of focus which also has relevance to many other diseases/conditions.
    • This final circumstance has considerable scope, so additional guidance is given below.


Generic Health Relevance as an additional code

If the main focus of the research is directed at several specified diseases and also has implications for many other conditions, the appropriate specific Health Categories should be used as well as applying the Generic category. (Note that this does not apply to diseases that may be listed within the background information or are noted as ‘being relevant’ to the study under investigation; many awards will reference multiple conditions to provide a context for the research, but always apply coding based on the lifetime of the award – (see the coding guidance on assigning health categories.)

Examples of this use of Generic Health Relevance coding appears across the HRCS guidance, including:


Official terminology

Full name of category

Short name Unique ID
Generic health relevance Generic



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