CT mucus plugs and emphysema were linked to COPD exacerbations

Design

Prospective cohort

Population

215 patients with COPD in China

Primary outcome

Acute exacerbation

Effect

High mucus/high emphysema vs low/low adjusted OR 3.30 (1.10-10.30)

This prospective Chinese cohort of 215 patients with COPD used quantitative CT to score mucus plugs (cut-off 4) and emphysema (cut-off 5% low attenuation) and grouped patients by both.

Compared with low mucus and low emphysema, the odds of exacerbation were about three times higher in each other group: high emphysema alone (OR 2.89), high mucus alone (3.13) and both (3.30). Each extra point of mucus plug score was associated with 11% higher odds.

The confidence intervals are wide and the study was modest. Mucus plugs on a CT already done for other reasons are worth noticing, but this does not justify CT for risk stratification alone.

• Note mucus plugs on any chest CT in a patient with COPD; they may mark higher exacerbation risk.
• Review airway clearance technique and inhaler therapy in patients with plugging.
• Use exacerbation history as the main predictor of future exacerbations.
• Do not order CT solely to score mucus plugs outside research.

Why it matters

It adds an imaging feature, often reported and ignored, to the picture of which patients are likely to exacerbate.

Don't overread it

This is an association in 215 patients; it does not show that treating mucus plugs prevents exacerbations.

The statistics, in plain English

Odds ratios around 3 look large, but the confidence intervals reach from about 1 to 10, reflecting a small study. The true effect could be small.

Read the rest in the app

You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.

Get Daily Doctor — free

Scan to keep reading on your phone. No account needed to start.