The aim of the RESPECT study is to gain a better understanding of the prevalence, pathogenesis and symptoms of early chronic obstructive pulmonary disease (COPD). This study seeks to address the following specific objectives/research questions: 1) to estimate the prevalence of airflow limitation (AL) and COPD in adults 35-70 years of age in St.Petersburg and Arkhangelsk based on sex, age, environmental conditions, socioeconomic status and smoking status; 2) to compare the prevalence of COPD in the study population based on the Global Strategy for Diagnosis, Management and Prevention of COPD (GOLD) and lower limit of normal (LLN) criteria; 3) to identify the diagnostic value of various signs, symptoms and background characteristics for the diagnosis of COPD; 4) to determine whether differences in background characteristics and inflammatory biomarkers are evident between smokers with and without COPD; and 5) to describe co-morbidity, functionality and global health status in a cohort of newly diagnosed COPD patients.

Two northwestern of Russian Federation (RF) cities (St.Petersburg and Arkhangelsk) were selected for the RESPECT study. Fifteen primary care centers were invited to participate in this study.

Fifteen investigators (10 from St.Petersburg and 5 from Arkhangelsk) were recruited (predominantly doctors and two highly educated nurses). All investigators received study information, including a detailed study protocol and recent guidelines on COPD, and participated in a three-week course on spirometry and the clinical diagnosis and management of obstructive lung diseases. The sample size was calculated based on two goals: 1) to determine a reliable estimate of the prevalence of COPD and 2) to estimate the diagnostic value of symptoms with an acceptable confidence interval.

The sample size for the RESPECT study was estimated using 2828 subjects (based on an 8% prevalence of COPD in RF). Assuming an anticipated refusal rate of 20%, 3500 participants from St.Petersburg and 1500 from Arkhangelsk were invited to participate in this study.

The analyses will include cross-sectional and prospective approaches. Prospective analyses will be performed on the entire cohort.

Inclusion Criteria:

•written consent to participate

Inclusion criteria for the cohort component:

•100 newly detected persons with FEV1/FVC less than 0.7 or less than LLN before and after reversibility test.

Inclusion criteria for the case-control component:

Both for cases and controls:

•A smoking history of more than 10 pack-years based on pack/year criteria

Test cases will include 100 participants that meet the following criteria:

• Smokers aged 35-70 years with a smoking history of >10 pack-years.
• Completely irreversible airway obstruction based on the following criteria: FEV1/FVC < 0.70 according to GOLD criteria or FEV1/FVC < LLN.

Test controls will include 100 participants based on the following criteria:

•Smokers aged 35-70 years with a smoking history of >10 pack/years and without COPD according to GOLD or LLN criteria, without asthma (absence of symptoms), with a negative history of allergies, and free from use of bronchodilators.

Exclusion Criteria:

• COPD exacerbation during last 3 months
• Patient did not sign an informed consent
• Patient refuses to participate

First component: The study population was randomly selected from the lists of the 15 participating centers (these patient lists are organized based on territories).

Second component (cohort study): All newly identified individuals with airflow limitation before and/or after the reversibility test were included in the cohort study.

Third component: One hundred patients with COPD and a smoking history of more than 10 pack-years (cases) and one hundred patients with the same smoking history without COPD (controls) will be included in the third study.