Airway inflammation contributes to health status in COPD: a cross-sectional study

Respiratory Research

Table 3 Association between sputum cell differential counts and health status assessed with SGRQ (n = 102), results from linear regression analyses.

		SGRQ total score	symptom score	activity score	impact score
Total cell count^†	B (95% CI)	-1.7 (-8.0 to 4.6)	-4.6 (-12 to 3.4)	-0.74 (-9.2 to 7.7)	-1.1 (-7.3 to 5.1)
% Neutrophils	B (95% CI)	-0.17 (-0.36 to 0.02)	-0.20 (-0.44 to 0.04)	-0.24 (-0.49 to 0.02)^‡‡	-0.11 (-0.30 to 0.08)
% Macrophages	B (95% CI)	0.22 (<0.01 to 0.43)*	0.28 (0.01 to 0.56)*	0.28 (-0.01 to 0.56)^‡	0.15 (-0.07 to 0.36)
% Eosinophils#	B (95% CI)	0.22 (-4.0–4.5)	-0.73 (-6.13–4.67)	2.42 (-3.27–8.10)	-0.61 (-4.80–3.58)

The univariate association between SGRQ scores (dependent) and sputum cell counts (independent) was expressed by regression coefficient B with corresponding 95% confidence intervals (95% CI). The regression coefficient B represents the strength of the association. Our results show that an increase in sputum macrophages of 1% is associated with an increase of the mean total score of 0.22 point, indicating that an increase in sputum macrophages of 20% is associated with an increase of the mean total score of 4.4 points, which exceeds the clinically relevant threshold of four units in SGRQ scores. ^†Total cell count was logtransformated; # % eosinophils were transformed using the square root. *p ≤ 0.05, ^‡p = 0.061, ^‡‡p = 0.068.

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