Table 2– Associations of serum uric acid levels with clinically relevant outcomes

	r_s coefficient	p-value
Age years	-0.563	0.320
Charlson score	0.117	0.039
BMI kg·m⁻²	-0.071	0.209
FEV₁ % predicted	-0.599	<0.001
Borg dyspnoea score	0.332	<0.001
Arterial blood gases
P_aO₂/F_IO₂ mmHg	-0.188	0.001
P_aCO₂ mmHg	0.165	0.003
Hospitalisation days	0.630	<0.001
Serum CRP mg·L⁻¹	0.287	<0.001

Bold indicates statistical significance. r_s: Spearman’s rank correlation coefficient; BMI: body mass index; FEV₁: forced expiratory volume in 1 s; P_aO₂: arterial oxygen tension; F_IO₂: inspiratory oxygen fraction; P_aCO₂: arterial carbon dioxide tension; CRP: C-reactive protein.