Development of the Short-Form Yin Deficiency Scale Using Three Item Reduction Approaches

Table 3

Differential item functioning results by sex and age.

Item (no.)	Sex				Age
	Male (logit)	Female (logit)	Chi-square value	value	Younger (logit)	Older (logit)	Chi-square value	value
Night cough (Q1)	0.67	0.76	0.142	0.706	0.85	0.63	1.814	0.178
Persistent cough (Q2)	0.70	0.48	3.355	0.067	0.72	0.35	5.907	0.015
Afternoon cough (Q3)	0.87	0.92	0.272	0.602	1.05	0.81	0.426	0.514
Afternoon fever (Q4)	0.33	0.56	0.711	0.399	0.36	0.65	4.260	0.039
Afternoon flush (Q5)	0.43	0.43	0.006	0.940	0.33	0.54	2.301	0.129
Dry mouth (Q6)	−0.24	−0.24	0.399	0.528	−0.10	−0.37	1.195	0.274
Night fever (Q7)	0.24	0.42	0.945	0.331	0.19	0.55	6.495	0.011
Weakness of the lower limbs (Q8)	−0.11	−0.15	0.949	0.330	−0.05	−0.25	0.134	0.715
Dull pain of the ankle or knee (Q9)	0.06	−0.39	3.044	0.081	−0.24	−0.33	0.248	0.618
Low back pain (Q10)	−0.78	−0.78	0.015	0.902	−0.66	−0.90	0.063	0.802
Wake due to night urination (Q11)	−0.24	−0.24	0.018	0.893	−0.15	−0.32	2.847	0.091
Frequent urination (Q12)	−0.70	−0.48	1.464	0.226	−0.53	−0.53	0.036	0.850
Residual urine (Q13)	−0.05	0.34	1.377	0.241	0.50	0.02	4.509	0.034
Difficulty in containing the urine (Q14)	0.67	0.60	0.012	0.914	0.87	0.38	7.705	0.006
Morning fatigue (Q15)	−0.96	−1.19	0.292	0.589	−1.48	−0.82	6.700	0.010
Susceptibility of heat and cold (Q16)	−0.61	−0.97	1.488	0.223	−1.15	−0.64	5.001	0.025
Fatigue (Q17)	−1.27	−1.54	1.199	0.274	−1.35	−1.60	1.424	0.233
Dry and cracked heel (Q18)	0.12	−0.02	0.281	0.596	−0.07	0.09	0.007	0.932
Night itch (Q19)	0.24	0.30	0.017	0.896	0.27	0.33	0.882	0.348
Dull pain of the heel (Q20)	0.30	0.33	0.435	0.510	0.33	0.33	0.118	0.731
Bone steaming (Q21)	0.77	0.82	0.886	0.347	0.99	0.68	6.234	0.013
Night hot soles (Q22)	0.48	0.18	0.241	0.624	0.09	0.41	7.401	0.007
Sweating during sleep (Q23)	−0.02	0.20	0.923	0.337	0.06	0.24	4.871	0.027
Tinnitus (Q24)	0.18	0.04	0.036	0.850	0.18	−0.03	0.467	0.494
Hair loss (Q25)	0.03	0.03	2.309	0.129	−0.16	0.21	0.010	0.922
Rough skin (Q26)	−0.22	−0.22	0.160	0.689	−0.36	−0.09	3.697	0.055
Dark yellow urine (Q27)	−0.76	−0.25	5.288	0.022	−0.40	−0.32	0.307	0.580

The values in bold indicate significant differences in logit values between sexes or higher and lower age groups.