Table 2.

The occurrence of moderate-to-severe AECOPD in the follow-up period.

	The conventional treatment group (n = 30)	The vaccination strategy group (n = 31)	The oral probiotics group (n = 27)	The aerosol inhaled amikacin group (n = 24)	p value*
days to the first moderate-to-severe AECOPD	198.2 ± 75.4	239.7 ± 46.5	248.8 ± 29.0	237.3 ± 43.5	0.026*
the frequency of moderate-to-severe exacerbations	0.84 ± 0.91	0.53 ± 0.79	0.58 ± 0.68	0.57 ± 0.68	0.614
the difference of the frequency of moderate-to-severe AE before and after the treatment	0.79 ± 0.75	1.42 ± 1.79	0.54 ± 0.75	0.86 ± 0.62	0.130

Data are shown as means ± standard deviation. p value was derived from comparison among groups. *p value < 0.05.

AECOPD, acute exacerbation of chronic obstructive pulmonary disease; AE, acute exacerbation.