What is ECRHS IV?

ECRHS IV is a follow-up prospective survey of around 2,000 adults who were first recruited in 1992-1994.  ECRHS II contacted the original participants 10 years later 1998-2002, with ECRHS III being the third wave of data collection on the cohort, beginning in 2008, and ECRHS IV the fourth data collection wave initiated in 2021. Until now (December 2025) data for ECRHS IV has been collected in 7 countries with clinical investigations (Denmark, Norway, Estonia, Sweden, Iceland, Spain, Australia) and one country with questionnaire data only (United kingdom).
In ECRHS IV, individuals who took part in the clinical stage of ECRHS I and were still alive were invited to a questionnaire survey and/or for a clinical investigation an outpatient or lung function laboratory in a local hospital or Centre. 

The study was primarily funded by two EU projects:

• BRUSH (#804199), an ERC starting grant awarded Randi Bertelsen, Bergen, Norway

• An EU Horizon 2020 grant (Work life exposome, lung function and COPD) in EPHOR (#874703, call SCi-BHC-2018-2020)

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Data collection is ongoing.

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The aims of ECRHS IV are:

1. Describe incidence and prevalence of chronic obstructive lung disease (COPD)

2. Investigate the impact of environmental and oral microbiome on asthma, lung function and other respiratory diseases

3. Explore predictors for COPD and impaired sleep

4. Describe Occupational Exposome and its relation to lung function decline and COPD

5. Explore the importance of susceptibility biomarkers as predictors, effect modifiers or mediators on lung health

6. Describe the association of obesity and physical exercise with asthma and lung function

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Differences in observed effects in men and women will be assessed. Data generated through this project will also be analysed to provide observational evidence of the importance of generational effects, sex specific risk factors and outcomes, and environmental factors with respiratory symptoms, lung function decline, and the development of COPD.

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In the local fieldwork centres the following procedures were performed:

• Detailed administered questionnaire asking about symptoms, exposure to known or suspected risk factors for asthma, and health service utilization

• Generic Quality of life tool and a disease-specific measure of quality of life

• Blood and urine samples for (future) research on exposure and effect biomarkers

• Dust samples, saliva, faeces, gingival samples, gums samples, sit-stand test (some centres)

• Measurement of lung function (FEV1 and FVC); for some centres measurement of bio-impendence; measurement of exhaled nitric oxide (FeNO)

• The Asthma Control Test

• A food frequency questionnaire

• Specific questionnaires for women and men

• The International Physical Activity Questionnaire

• A body shape questionnaire

• A sleep questionnaire

• An exposure to sunlight questionnaire