Table 1. Coding scheme for lung mucus.

A scale from 0-6 was used to code lung mucus on PAS-stained lung slides.

Mucus Score	Description
0	No mucus or very small amounts of mucus
1	Partial thin outline of mucus on 1–2 inner airways
2	Full mucus outline around inner airway on 1–2 airway(s)
3	Full mucus outline on 3 airways
4	Mucus covering 1 entire airway OR mucus outline on 4+ airways
5	Mucus covering 1 entire airway AND mucus outline on 1+ airway(s)
6	Mucus covering 2+ airways AND mucus outline on 2+ airways