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Common Aggregation Hierarchy - list

The Common Aggregation Hierarchy (CAH) provides a standardised hierarchical aggregation of HECoS codes suitable for the majority of uses.

The table below shows the simplified view of the Common Aggregation Hierarchy (version 1.3.4)

Read more about the Common Aggregation Hierarchy

Download the Common Aggregation Hierarchy (version 1.2)

Download the Common Aggregation Hierarchy (version 1.3.4)

Common Aggregation Hierarchy (version 1.3.4)

In version 1.3.4 of the CAH, level 1 comprises 21 groups; level 2 comprises 35 groups; level 3 comprises 167 groups.

CAH1 level 1

CAH2 level 2

CAH3 level 3

(CAH01) medicine and dentistry

(CAH01-01) medicine and dentistry

(CAH01-01-01) medical sciences (non-specific)

(CAH01-01-02) medicine (non-specific)

(CAH01-01-03) medicine by specialism

(CAH01-01-04) dentistry

(CAH02) subjects allied to medicine

(CAH02-02) pharmacology, toxicology and pharmacy

(CAH02-02-01) pharmacology

(CAH02-02-02) toxicology

(CAH02-02-03) pharmacy

(CAH02-04) nursing and midwifery

(CAH02-04-01) nursing (non-specific)

(CAH02-04-02) adult nursing

(CAH02-04-03) community nursing

(CAH02-04-04) midwifery

(CAH02-04-05) children's nursing

(CAH02-04-06) dental nursing

(CAH02-04-07) mental health nursing

(CAH02-04-08) learning disabilities nursing

(CAH02-04-09) others in nursing

(CAH02-05) medical sciences

(CAH02-05-01) medical technology

(CAH02-05-02) healthcare science (non-specific)

(CAH02-05-03) biomedical sciences (non-specific)

(CAH02-05-04) anatomy, physiology and pathology

(CAH02-06) allied health

(CAH02-06-01) health sciences (non-specific)

(CAH02-06-02) nutrition and dietetics

(CAH02-06-03) ophthalmics

(CAH02-06-04) environmental and public health

(CAH02-06-05) physiotherapy

(CAH02-06-06) complementary and alternative medicine

(CAH02-06-07) counselling, psychotherapy and occupational therapy

(CAH03) biological and sport sciences

(CAH03-01) biosciences

(CAH03-01-01) biosciences (non-specific)

(CAH03-01-02) biology (non-specific)

(CAH03-01-03) ecology and environmental biology

(CAH03-01-04) microbiology and cell science

(CAH03-01-05) plant sciences

(CAH03-01-06) zoology

(CAH03-01-07) genetics

(CAH03-01-08) molecular biology, biophysics and biochemistry

(CAH03-01-09) hair and beauty sciences

(CAH03-01-10) others in biosciences

(CAH03-02) sport and exercise sciences

(CAH03-02-01) sport and exercise sciences

(CAH04) psychology

(CAH04-01) psychology

(CAH04-01-01) psychology (non-specific)

(CAH04-01-02) applied psychology

(CAH04-01-03) developmental psychology

(CAH04-01-04) psychology and health

(CAH04-01-05) others in psychology

(CAH05) veterinary sciences

(CAH05-01) veterinary sciences

(CAH05-01-01) veterinary medicine and dentistry

(CAH05-01-02) others in veterinary sciences

(CAH06) agriculture, food and related studies

(CAH06-01) agriculture, food and related studies

(CAH06-01-01) animal science

(CAH06-01-02) agricultural sciences

(CAH06-01-03) agriculture

(CAH06-01-04) rural estate management

(CAH06-01-05) forestry and arboriculture

(CAH06-01-06) food and beverage studies (non-specific)

(CAH06-01-07) food sciences

(CAH06-01-08) food and beverage production

(CAH07) physical sciences

(CAH07-01) physics and astronomy

(CAH07-01-01) physics

(CAH07-01-02) astronomy

(CAH07-02) chemistry

(CAH07-02-01) chemistry

(CAH07-04) general, applied and forensic sciences

(CAH07-04-01) physical sciences (non-specific)

(CAH07-04-02) forensic and archaeological sciences

(CAH07-04-03) sciences (non-specific)

(CAH07-04-04) natural sciences (non-specific)

(CAH09) mathematical sciences

(CAH09-01) mathematical sciences

(CAH09-01-01) mathematics

(CAH09-01-02) operational research

(CAH09-01-03) statistics

(CAH10) engineering and technology

(CAH10-01) engineering

(CAH10-01-01) engineering (non-specific)

(CAH10-01-02) mechanical engineering

(CAH10-01-03) production and manufacturing engineering

(CAH10-01-04) aeronautical and aerospace engineering

(CAH10-01-05) naval architecture

(CAH10-01-06) bioengineering, medical and biomedical engineering

(CAH10-01-07) civil engineering

(CAH10-01-08) electrical and electronic engineering

(CAH10-01-09) chemical, process and energy engineering

(CAH10-01-10) others in engineering

(CAH10-03) materials and technology

(CAH10-03-01) minerals technology

(CAH10-03-02) materials technology

(CAH10-03-03) polymers and textiles

(CAH10-03-04) maritime technology

(CAH10-03-05) biotechnology

(CAH10-03-06) others in technology

(CAH10-03-07) materials science

(CAH11) computing

(CAH11-01) computing

(CAH11-01-01) computer science

(CAH11-01-02) information technology

(CAH11-01-03) information systems

(CAH11-01-04) software engineering

(CAH11-01-05) artificial intelligence

(CAH11-01-06) computer games and animation

(CAH11-01-07) business computing

(CAH11-01-08) others in computing

(CAH26) geography, earth and environmental studies

(CAH26-01) geography, earth and environmental studies

(CAH26-01-01) geography (non-specific)

(CAH26-01-02) physical geographical sciences

(CAH26-01-03) human geography

(CAH26-01-04) environmental sciences

(CAH26-01-05) others in geographical studies

(CAH26-01-06) earth sciences

(CAH13) architecture, building and planning

(CAH13-01) architecture, building and planning

(CAH13-01-01) architecture

(CAH13-01-02) building

(CAH13-01-03) landscape design

(CAH13-01-04) planning (urban, rural and regional)

(CAH15) social sciences

(CAH15-01) sociology, social policy and anthropology

(CAH15-01-01) social sciences (non-specific)

(CAH15-01-02) sociology

(CAH15-01-03) social policy

(CAH15-01-04) anthropology

(CAH15-01-05) development studies

(CAH15-01-06) cultural studies

(CAH15-02) economics

(CAH15-02-01) economics

(CAH15-03) politics

(CAH15-03-01) politics

(CAH15-04) health and social care

(CAH15-04-01) social work

(CAH15-04-02) childhood and youth studies

(CAH15-04-03) health studies

(CAH16) law

(CAH16-01) law

(CAH16-01-01) law

(CAH17) business and management

(CAH17-01) business and management

(CAH17-01-01) business and management (non-specific)

(CAH17-01-02) business studies

(CAH17-01-03) marketing

(CAH17-01-04) management studies

(CAH17-01-05) human resource management

(CAH17-01-06) tourism, transport and travel

(CAH17-01-07) finance

(CAH17-01-08) accounting

(CAH17-01-09) others in business and management

(CAH24) media, journalism and communications

(CAH24-01) media, journalism and communications

(CAH24-01-01) information services

(CAH24-01-02) publicity studies

(CAH24-01-03) publishing

(CAH24-01-04) journalism

(CAH24-01-05) media studies

(CAH19) language and area studies

(CAH19-01) English studies

(CAH19-01-01) English studies (non-specific)

(CAH19-01-02) English language

(CAH19-01-03) literature in English

(CAH19-01-04) studies of specific authors

(CAH19-02) Celtic studies

(CAH19-01-05) creative writing

(CAH19-01-06) others in English studies

(CAH19-01-07) linguistics

(CAH19-02-01) Celtic studies (non-specific)

(CAH19-04) languages and area studies

(CAH19-02-02) Gaelic studies

(CAH19-02-03) Welsh studies

(CAH19-02-04) others in Celtic studies

(CAH19-04-01) French studies

(CAH19-04-02) German and Scandinavian studies

(CAH19-04-03) Italian studies

(CAH19-04-04) Iberian studies

(CAH19-04-05) Slavic studies

(CAH19-04-06) Asian studies

(CAH19-04-07) African and modern Middle Eastern studies

(CAH19-04-08) American and Australasian studies

(CAH19-04-09) others in language and area studies

(CAH20) historical, philosophical and religious studies

(CAH20-01) history and archaeology

(CAH20-01-01) history

(CAH20-01-02) history of art, architecture and design

(CAH20-01-03) archaeology

(CAH20-01-04) heritage studies

(CAH20-01-05) classics

(CAH20-02) philosophy and religious studies

(CAH20-02-01) philosophy

(CAH20-02-02) theology and religious studies

(CAH25) design, and creative and performing arts

(CAH25-01) creative arts and design

(CAH25-01-01) creative arts and design (non-specific)

(CAH25-01-02) art

(CAH25-01-03) design studies

(CAH25-01-04) cinematics and photography

(CAH25-01-05) others in creative arts and design

(CAH25-02) performing arts

(CAH25-02-01) performing arts (non-specific)

(CAH25-02-02) music

(CAH25-02-03) drama

(CAH25-02-04) dance

(CAH22) education and teaching

(CAH22-01) education and teaching

(CAH22-01-01) education

(CAH22-01-02) teacher training

(CAH23) combined and general studies

(CAH23-01) combined and general studies

(CAH23-01-01) combined, general or negotiated studies

(CAH23-01-02) personal development

(CAH23-01-03) humanities (non-specific)

(CAH23-01-04) liberal arts (non-specific)