. 2021 Mar;13(3):1517–1530. doi: 10.21037/jtd-20-2790

Table 6. Multivariate linear regression models of the impact of duration of hospitalization and severity on quantitative CT-based airway dimension in patients with COVID-19 at the convalescent stage.

Variables	β	95% CI		P value for β	Adjusted R²	P value for adjusted R²
Variables	β	Lower limit	Upper limit	P value for β	Adjusted R²	P value for adjusted R²
Duration of hospitalization
1st gen. WA (%)^†	−0.0007	−0.0014	0.0000	0.051	0.164	0.004
2nd gen. WA (%)^†	−0.0012	−0.0019	−0.0004	0.002	0.213	0.001
3rd gen. WA (%)^†	−0.0016	−0.0025	−0.0006	0.001	0.218	0.001
4th gen. WA (%)^†	−0.0012	−0.0018	−0.0005	0.001	0.227	<0.001
5th gen. WA (%)^†	−0.0009	−0.0014	−0.0004	0.001	0.271	<0.001
6th gen. WA (%)^†	−0.0008	−0.0012	−0.0003	0.001	0.245	<0.001
7th gen. WA (%)^†	−0.0006	−0.0013	0.0001	0.098	0.066	0.080
8th gen. WA (%)^‡	−0.0006	−0.0013	0.0000	0.038	0.062	0.093
Pi10 (mm)^†	−0.0027	−0.0058	0.0005	0.097	0.285	<0.001
Severity
1st gen. WA (%)^§	−0.0054	−0.0182	0.0073	0.400	0.119	0.016
2nd gen. WA (%)^§	−0.0080	−0.0223	0.0063	0.268	0.097	0.032
3rd gen. WA (%)^§	−0.0173	−0.0354	0.0008	0.061	0.109	0.022
4th gen. WA (%)^§	−0.0151	−0.0280	−0.0021	0.023	0.134	0.010
5th gen. WA (%)^§	−0.0061	−0.0162	0.0040	0.231	0.116	0.018
6th gen. WA (%)^§	−0.0052	−0.0141	0.0038	0.253	0.106	0.024
7th gen. WA (%)^§	0.0007	−0.0125	0.0138	0.920	0.007	0.358
8th gen. WA (%)^‡	0.0016	−0.0091	0.0124	0.761	−0.007	0.483
Pi10 (mm)^§	−0.0079	−0.0663	0.0506	0.789	0.248	<0.001

All models adjusted for sex, age and smoking status. Sample size of the models: ^†, denotes n=68; ^‡, denotes n=67; ^§, denotes n=69. CI, confident interval; WA%, wall area fraction; gen., generation; Pi10, internal airway perimeter of 10 mm.