Table 4.

Test–retest reliability of the final Hie questionnaire

	Autumn					Winter
	First time		Second time		P	First time		Second time		P
	N	Mean ± SD	N	Mean ± SD		N	Mean ± SD	N	Mean ± SD
Total score of the Hie questionnaire	112	26.9 ± 7.7	108	26.2 ± 7.9	NS	108	20.3 ± 7.9	94	20.3 ± 8.7	NS
Level of Hie
Severe	5	41.4 ± 1.5	5	40.8 ± 1.1	NS	0	–	0	–
Moderate	46	32.9 ± 2.5	38	33.3 ± 2.5	NS	9	33.3 ± 2.5	14	32.1 ± 2.4	NS
Slight	38	24.5 ± 2.7	38	24.6 ± 2.8	NS	54	24.4 ± 3.0	42	24.5 ± 2.7	NS
Not apparent	23	15.7 ± 2.7	27	15.9 ± 2.6	NS	45	12.7 ± 5.1	38	11.3 ± 4.8	NS

Total score of Hie ranged from 10 to 50 points. The levels of Hie were defined as follows: Severe ≥40, 30< moderate <40, 20≤ slight <30, not apparent <20. Test–retest reliability was evaluated by the paired t test (two-tailed) using Satterthwaite’s approximation for adjusting unequal variances

NS not significant