Table 3

Univariate analysis in terms of the frequency of exacerbation

Factor	r	95% CI	p Value
Age	0.21	−0.037 to 0.43	0.095
BMI	−0.010	−0.33 to 0.15	0.435
Smoking history pack-year	−0.06	−0.30 to 0.19	0.648
I-SW/SW-I rate	0.37	0.14 to 0.56	0.002
Deglutition apnoea duration	0.27	0.029 to 0.48	0.028
Swallowing latency	0.29	0.046 to 0.50	0.020
FSSG score	0.12	−0.13 to 0.35	0.341
CAT	0.28	0.04 to 0.49	0.025
mMRC Dyspnoea Scale score	0.19	−0.06 to 0.42	0.131
FEV1	−0.30	−0.51 to −0.06	0.013
%FEV1	−0.24	−0.45 to 0.008	0.057
FVC	−0.21	−0.43 to 0.035	0.093
FEV1/FVC	−0.27	−0.48 to −0.03	0.028
VC	−0.32	−0.53 to −0.09	0.007
%VC	−0.25	−0.47 to −0.001	0.049
IC/TLC	−0.35	−0.54 to −0.11	0.004
RV/TLC	0.23	−0.01 to 0.45	0.064
DLco	−0.36	−0.55 to −0.12	0.003

BMI, body mass index; CAT, Chronic Obstructive Pulmonary Disease Assessment Test; DLco, diffusing capacity of carbon monoxide; FEV1, forced expiratory volume in 1 s; FSSG, frequency scale for symptoms of gastro-oesophageal reflux disease; FVC, forced vital capacity; IC, inspiratory capacity; I-SW, swallowing during inspiration; mMRC, modified Medical Research Council; r, Pearson’s correlation coefficient; RV, residual volume; SW-I, swallowing immediately followed by inspiration; TLC, total lung capacity; VC, vital capacity.