Congenital disorders and inherited syndromes
Advice on health categories
Congenital Disorders should be used to code physical abnormalities and congenital syndromes that are associated with multiple diseases and conditions e.g. cystic fibrosis.
Inherited disorders associated with a single disease or condition should be coded under the appropriate Health Category and not as Congenital Disorders.
e.g. heart defects present at birth should be coded as Cardiovascular.
Advice on health categories
Elevated blood lipids and high cholesterol levels are considered to be a disorders of metabolic regulation and studies in this area are classified as Metabolic and Endocrine. This includes studies of HDL (high density lipoprotein), LDL (low density lipoprotein) and triglycerides.
Studies on nutrition, diet and obesity specifically aimed at reducing cholesterol levels should be coded as Metabolic. However such studies are often context based and should only be coded as Metabolic if they relate to metabolism.
Advice on health categories
Cerebral palsy is a neurological disorder which can be acquired as a result of conditions in pregnancy, birth or childhood and is therefore coded as Neurological and not Congenital Disorders.
Spina bifida is a developmental birth defect involving the neural tube and is usually coded as Neurological.
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.
Advice on health categories
In studies of cancer, only the Cancer category should be used – do not code for the site. This is in line with the coding guidance to assign health categories based on the main disease and not pathogenesis or site of action. However if the research involves studying a condition that predisposes to cancer, it may be appropriate to also code for the condition.
e.g. studies of Barrett’s oesophagus in relation to cancer would be 50% Oral and Gastrointestinal and 50% Cancer.
e.g. studies of pathogens and their association with the development of cancer, such as Human Papilloma Virus (HPV) or Helicobacter pylori, should be coded 50% Infection and 50% Cancer.
Studies of the normal role of oncogenes and tumour suppressor genes in a non diseased cell may be coded as 50% Generic Health Relevance and 50% Cancer.
Advice on research activities
Cancer is not a ‘normal’ process and hence studies that specifically relate to the cause of cancer are rarely coded within the 1 Underpinning code group.
In particular studies of abnormal cell cycle or DNA repair in relation to cancer should not be coded within the 1 Underpinning code group.
Studies of the normal role of oncogenes and tumour suppressor genes in a non diseased cell should be coded as 50% 1.1 Biological and 50% 2.1 Endogenous risks.
Advice on research activities
The term ‘biomarker’ in general refers to a specific molecule, gene or characteristic from which a physiological process can be identified. Biomarkers are typically coded in one of three research activity groups:
2 Aetiology: Where markers may be first identified in epidemiology studies or further assessed to determine how the molecule/gene/etc. contribute to the cause, risk or development of disease.
4 Detection and Diagnosis: Where studies of biomarker discovery and biomarkers screening for the purposes of disease diagnosis or prognosis are usually within 4 Detection and Diagnosis.
5 Treatment Development: Specifically where markers are used to develop treatments. However if looking at pharmacogenetic studies in pre-clinical settings or model systems, most commonly in pharmacogenetic studies (5.1) it should be classified in 5 Treatment Development. Identification of receptor pathways should be classified in 2 Aetiology.
Examples:
- The initial discovery of BRCA1 gene mutations as potential risk factors for breast cancer in epidemiology studies and would be coded in 2 Aetiology.
- Characterisation of BRCA1 gene, protein and pathway in cancer would likewise be coded in 2 Aetiology.
- The pre-clinical development and subsequent clinical application of techniques for screening for BRCA1 mutations to determine diagnosis or prognosis would be coded 4 Detection & Diagnosis.
- Assessment of BRCA1 expression for pharmacogenetics in drug development would be coded 5.1 Treatment Development – Pharmaceuticals.
Advice on health categories
Studies of inner ear vestibular function or disorders are classified as Ear.
Other studies of balance, dizziness and vertigo involving a specific central nervous component should be classified as Neurological.
If there is a specific cognitive/perceptual aspect it may be appropriate to classify as Mental Health.
Advice on health categories
Some cardiovascular conditions such as atherosclerosis arise from involvement of the immune system but they should be coded as 100% Cardiovascular and not coded to Inflammatory and Immune System, even if the research is, for example, focused on transformation of macrophages to foam cells.
This is in line with the coding guidance to assign health categories based on the main disease and not pathogenesis or site of action.
Advice on health categories
In general studies of animal welfare should be assigned the Disputed Aetiology and Other category. This applies to studies with direct focus on laboratory animals and the use of animals in human health research. The wider field of veterinary research is outside the scope of HRCS.
However, if developing models or new techniques with the aim of replacing or reducing animals in research, the Health Category should reflect the subject area of the research.
e.g. a new assay replacing an animal model used in respiratory infection studies should be coded as Infection.
Advice on research activities
General studies of animal welfare and the development of models or new techniques with the aim of replacing or reducing animals in research should be coded to the infrastructure code appropriate to the nature of the study.
Advice on health categories
The coding for studies on alcohol will depend on the nature of the research.
Use Mental Health for any studies of alcohol addiction/misuse and resulting behavioural problems.
Use Oral and Gastrointestinal for studies of cirrhosis following alcohol misuse.
Only use the following standardised breakdown of health categories and percentages for general studies on alcohol consumption where there is no other indication of disease area:
| Health Category | Percentage |
|---|---|
| Cancer and neoplasms | 25 |
| Cardiovascular | 25 |
| Oral and Gastrointestinal | 25 |
| Stroke | 25 |
The standardised breakdown choices select the four main health categories that will be most affected by alcohol consumption. If the study aim relates to these (or any other health category) individually, then the normal rules of HRCS apply:
e.g. “Alcohol misuse and risk of breast cancer” would be 100% Cancer.
e.g. “Reducing health burden by a new alcohol advice service” would use the standardised breakdown (unless the abstract / application text indicates otherwise).
Advice on research activities
Alcohol consumption is considered a risk factor for other diseases. Therefore, interventions to reduce alcohol consumption should be coded as 3 Prevention, even if the person already drinks. Use 5 Treatment Development or 6 Treatment Evaluation for studies focussed on treatment of an existing alcohol-related disease and in cases of secondary prevention.
Additional guidance on differentiating secondary and primary prevention is also available.