Underdiagnosis of Obstructive Lung Disease

Findings From the French CONSTANCES Cohort

Marie-Christine Delmas; Laetitia Bénézet; Céline Ribet; Yuriko Iwatsubo; Marie Zins; Rachel Nadif; Nicolas Roche; Bénédicte Leynaert


BMC Pulm Med. 2021;21(319) 

In This Article

Abstract and Introduction


Background: The burden of undiagnosed obstructive lung disease (OLD) (mainly asthma and chronic obstructive pulmonary disease) is not fully established, and targets for corrective action are yet to be identified. We assessed the underdiagnosis of OLD and its determinants in France.

Methods: CONSTANCES is a French population-based cohort of adults aged 18–69 years at inception. We analysed data collected at inclusion in 2013–2014. Undiagnosed OLD was defined as spirometry-confirmed airflow limitation (FEV1/FVC < lower limit of normal) without prior diagnosis of asthma, chronic obstructive pulmonary disease, or bronchiectasis. Multivariate analysis was performed with weighted robust Poisson regression models to estimate the adjusted prevalence ratios (aPR) of undiagnosed OLD.

Results: Spirometry results were available for 19,398 participants. The prevalence of airflow limitation was 4.6%. Overall, 64.4% of adults with airflow limitation did not report a previous diagnosis of OLD. Individuals with high cumulative tobacco consumption (≥ 10 pack-years) (aPR: 1.72 [1.28–2.32]), without respiratory symptoms (aPR: 1.51 [1.28–1.78]), and with preserved lung function (aPR: 1.21 [1.04–1.41] for a 10-point increase in FEV1% predicted) had a higher risk of being undiagnosed. Half of symptomatic individuals with airflow limitation (45% of those with moderate to severe airflow limitation) were undiagnosed with OLD.

Conclusion: Underdiagnosis of OLD is very common among French adults, even in patients with respiratory symptoms. Efforts should be made in France to raise awareness about OLD in the general population, improve the detection of respiratory symptoms, and increase the use of spirometry among primary care professionals.


Obstructive lung disease (OLD), which mainly relates to asthma and chronic obstructive pulmonary disease (COPD), is both common and serious, representing a growing public health challenge worldwide.[1] Nevertheless, asthma and COPD are frequently undiagnosed. Regarding asthma, population-based studies showed that 20% to 70% of adults with current asthma remained undiagnosed.[2] A pooled analysis of national and international COPD surveys estimated that 81% of COPD patients were undiagnosed.[3] In France, the most recent estimate of the prevalence of current asthma in adults varies from 6 to 9% according to the definition.[4] In the early 2000s, the prevalence of airflow limitation (based on pre-bronchodilator tests) was estimated at 7.5% among non-asthmatic individuals aged 45 years and over.[5] A recent study conducted in middle-aged adults living in two northern French cities showed prevalence estimates ranging from 9.5% to 16.0% according to the city and definition used.[6] More than 70% of those with airflow limitation did not report a diagnosis of OLD.

Undiagnosed OLD is associated with negative health outcomes such as respiratory symptoms, functional impairment and exacerbation, treatment delays, and substantial healthcare utilisation.[7–9] Identifying the factors that contribute to undiagnosed OLD is therefore essential. The present analysis aimed to estimate the prevalence of undiagnosed OLD and identify the risk factors for underdiagnosis in the large French population-based CONSTANCES cohort.