Table 5– Comparison of the clinical features of the patients with acute exacerbation (AE) and the bilateral infection at the time of rapid deterioration (RD)

Characteristics	AE	Infection	p-value
Patients	90	37
Age yrs	65.3±7.9	66.1±7.6	ns
Males	69 (76.7)	30 (81.1)	ns
Disease duration months	16.5±24.5	29.5±34.7	0.014
Steroid with/without cytotoxic agent use^#	56 (62.2)	20 (54.1)	ns
Duration^¶ months	3.4±3.8	4.5±5.2	ns
Last dose^¶ mg	18.8±13.2	18.4±15.0	ns
Duration of dyspnoea days	11.2±12.5	6.1±7.4	0.030
Initial symptoms
Documented fever	18 (20.0)	19 (51.4)	0.001
Sputum production	63 (70.0)	31 (83.8)	ns
CRP mg·dL⁻¹	8.3±6.8	14.7±9.8	<0.001
P_a,O₂/F_I,O₂	253±83	228±91	ns
BAL
Total cells·mm⁻³	292±168	349±342	ns
Lymphocytes %	19.7± 19.6	8.1±7.5	0.041
Neutrophils %	22.9±19.9	55.2±28.9	0.001

Data are presented as n, mean±sd or n (%), unless otherwise stated. CRP: C-reactive protein; P_a,O₂: arterial oxygen tension; F_I,O₂: inspiratory oxygen fraction; BAL: bronchoalveolar lavage; ns: nonsignificant. ^#: within 30 days prior to RD; ^¶: steroid (prednisolone) treatment.