From pre-COPD to COPD: a Simple, Low cost and easy to IMplement (SLIM) risk calculator

Area of Science:

• Pulmonology
• Respiratory Medicine
• Epidemiology

Background:

• Chronic Obstructive Pulmonary Disease (COPD) affects 13-22% of smokers.
• Early identification of individuals at risk for COPD is essential for timely intervention.
• This study aimed to identify predictors of chronic airflow limitation (CAL) in ever-smokers.

Purpose of the Study:

• To develop and validate a predictive model for incident chronic airflow limitation (CAL) in ever-smokers.
• To identify key clinical and physiological variables associated with CAL development.
• To enable early intervention strategies for at-risk individuals.

Main Methods:

• Analysis of 677 participants from the Lovelace Smokers' Cohort (LSC) with normal baseline spirometry and at least three follow-up measurements.
• Logistic regression used to identify predictors of incident CAL based on demographics, anthropometrics, smoking history, symptoms, and spirometry.
• Validation of the predictive model in the COPDGene study cohort.

Main Results:

• The incidence of CAL was 26 cases per 1000 person-years over 6.3 years.
• Key predictors of CAL included FEV1/FVC <0.75, smoking ≥30 pack-years, BMI ≤25 kg/m², and chronic bronchitis symptoms.
• A model combining these four factors predicted CAL development with 85% risk over 6 years (AUC ROC 0.84).
• The model demonstrated good performance in the COPDGene cohort (AUC ROC 0.77).

Conclusions:

• A simple predictive model incorporating FEV1/FVC, smoking history, BMI, and chronic bronchitis effectively identifies middle-aged ever-smokers at high risk of developing CAL.
• This model can aid in early detection and intervention for individuals susceptible to COPD.
• The findings support the use of readily available clinical data for risk stratification in smokers.