Undiagnosed COPD represents a significant issue in terms of morbidity and mortality, as nearly 50% of smokers with chronic respiratory symptoms also experience impaired quality of life and acute events similar to COPD exacerbations. We aim to study the prevalence of airflow obstruction (AO) and PRISm (preserved ratio impaired spirometry) in the general population.

Chronic Obstructive Pulmonary Disease (COPD), a chronic bronchial disease characterized by irreversible airway obstruction, represents a major public health issue. It is currently the fifth leading cause of death worldwide and, according to the World Health Organization (WHO), is expected to become the third leading cause by 2030. Diagnosis is currently based on spirometry, which reveals an obstructive ventilatory disorder (OVD) defined by a forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) ratio of less than 0.7. However, limited access to this examination can make the diagnosis of COPD difficult. Undiagnosed COPD represents a significant issue in terms of morbidity and mortality, as nearly 50% of smokers with chronic respiratory symptoms also experience impaired quality of life and acute events similar to COPD exacerbations. A French study involving 424 patients hospitalized for a COPD exacerbation found that 21.9% had not been diagnosed previously, meaning they entered the disease during a severe exacerbation. The main challenge, therefore, lies in the early identification of COPD patients, particularly through the use of validated self-questionnaires (e.g., Haute Autorité de Santé). We aim to study the prevalence of airflow obstruction (AO) and PRISm (preserved ratio impaired spirometry) in the general population. The secondary objectives are: to compare the clinical characteristics of patients with and without AO / with and without PRISm (depending on sample size). To identify risk factors for AO and/or PRISm (depending on sample size) (female sex, advanced age, BMI, active smoking, respiratory symptoms). To estimate the prevalence of "undiagnosed" subjects, defined as the presence of OVD without any known respiratory history, and to study their clinical characteristics. We plan to follow up with participants at 6 months through a telephone contact to assess the practical impact of this screening day and to determine the proportion of those who have received a consultation with a general practitioner, a pulmonologist, or the introduction of a treatment.

• Inclusion criteria :
• Age ≥ 18 years
• Participating to the prevention campain "Mai Poumons 2026" on 09 Mai 2026
• Exclusion criteria :
• Contre-indication to perform a spirometry : hemoptysy, pneumothorax, myocardal infarction <1month, thoracic anevrism, recent ophtalmologic, abdominal or thoracic surgery
• Unable to perform a spirometry (understanding, coordination)
• Patient under legal protection
• Patient pregnant or breasting
• Not affiliating to public healthcare
• Patient deprived of liberty

Population attending the "9 Mai Poumon 2026" prevention campaign