TABLE 2.

One year incidence rates and incidence rate ratios of acute exacerbation in respect of severity among the study subjects.

	PIFR group (n = 160)	Control group (n = 223)	Incidence rate ratio (PIFR group to control group)	p value
Total AE	0.88 (0.71–1.06)	1.14 (0.94–1.34)	0.84 (0.62–1.13)	0.245
Mild AE	0.11 (0.06–0.16)	0.17 (0.11–0.23)	0.68 (0.37–1.23)	0.203
Moderate AE	0.55 (0.42–0.68)	0.55 (0.28–0.57)	1.11 (0.79–1.57)	0.546
Severe AE	0.18 (0.09–0.27)	0.43 (0.28–0.57)	0.52 (0.32–0.87)	0.012
Moderate-severe AE	0.77 (0.60–0.94)	0.98 (0.79–1.16)	0.88 (0.64–1.20)	0.401

Data presented as mean (95% confidence intervals). AE: acute exacerbation. Incidence rate was calculated as events/patient/year. PIFR group: patients who received PIFR-guided inhalation therapy.