Table 6. The comparisons for the differences in coughing scores as assessed by the parents among the four groups by Kruskal—Wallis test.

Parameters	IFN Injection	Control	IFN Nebulization 1	IFN Nebulization 2	χ2	P
The differences of parents’ coughing score of days 1 and 3	2.29±0.19	1.41±0.11	1.82±0.14	2.46±0.16	25.727	<0.001
The differences of parents’ coughing score of days 3 and 5	2.24±0.13	1.83±0.13	2.22±0.12	2.21±0.15	8.192	0.042
The differences of parents’ coughing score of days 5 and 7	1.95±0.15	1.45±0.11	1.50±0.12	1.54±0.21	6.904	0.075