Antibiotic perturbation of mixed-strain Pseudomonas aeruginosa infection in patients with cystic fibrosis

BMC Pulmonary Medicine

Table 2 Comparison of clinical outcome data for the 12 patients with single- and mixed-strain infections

Clinical parameter	Single-strain infection					Mixed-strain infection
Clinical parameter	Patients (number)	Start-of-treatment Mean (SD)	End-of-treatment Mean (SD)	Mean difference (95% CI)	P-value	Patients (number)	Start-of-treatment Mean (SD)	End-of-treatment Mean (SD)	Mean difference (95% CI)	P-value
(a) Response to treatment
FEV₁% pred ^a	7	31.2 (20.2 to 84.0)	36.0 (31.2-99.8)	7.2 (3.1 to 15.8) ^b	0.02	5	41.7 (30.3 to 63.1)	41.6 (30.3 to 65.5)	2.4 (0.0 to 14.5) ^b	0.07
BMI (kg/m²)	7	23.2 (6.4)	23.3 (6.3)	0.1 (−0.3 to 0.6)	0.51	5	21.6 (3.5)	21.8 (3.9)	0.2 (−0.9 to 1.2)	0.65
CRP (mmol/L)	7	32.2 (28.6)	6.2 (4.9)	−27.0 (−53.9 to −0.2)	0.05	5	10.3 (8.7)	11.1 (8.0)	0.7 (−2.2 to 3.6)	0.52
Treatment length; mean days (SD)				15.0 (4.3)					16.6 (6.6)	0.65
(b) Longer-term outcomes
	Single-strain infection (n = 7)					Mixed-strain infection (n = 5)				P-value
Relapse ^c; no. (%)	0 (0)					2.0 (40.0)				0.15
Hospitalisation recurrence ^d; median days (range)	154.0 (39.0 to 711.0)					85.0 (44.0 to 145.0)				0.12

Abbreviations: BMI Body mass index, CI confidence interval, CRP C-reactive protein, FEV ₁ % pred forced expiratory volume in the first second percentage predicted, SD standard deviation
^amedian (range) shown for all FEV1% pred data
^bWilcoxon signed rank test used to assess within-pair differences
^cDefined as readmission to hospital before outpatient review occurred
^dTime to next recurrence requiring hospitalisation; data censored for one patient with single-strain infection (time to end of data collection as no recurrence of hospitalisation experienced)

ISSN: 1471-2466