Table 3.

Scoring system used for examination of histological abnormalities and for cilia in the trachea.

Tissue scores	Criteria for histological abnormalities	Scoring criteria for cilia
0	No significant histological abnormality is recognised (NHAIR)	Dense, long cilia
1	Minimal – mild changes	Mild shortening or irregularity of cilia
2	Modest – moderate changes	Moderate shortening/irregularity of cilia
3	Marked (multi)focal changes	Marked irregularity with focal cilia loss
4	Marked, extensive/diffuse changes	Marked irregularity with diffuse cilia loss