Validity of a Diagnostic Scale for Acupuncture: Application of the Item Response Theory to the Five Viscera Score
Table 2
Item discrimination and difficulty of the Five Viscera Score by Item Response Theory. ().
Subscale
Item number
Item
a (SE)
Mean b
b1 (SE)
b2 (SE)
b3 (SE)
b4 (SE)
Factor loading
Cronbach's α
Liver
0.77
Q1
I have a stiff neck
2.11 (0.11)
0.11
−0.76 (0.10)
−0.22 (0.07)
0.35 (0.08)
1.07 (0.13)
0.82
Q2
I have a pulled muscle in my neck
2.57 (0.14)
0.55
−0.14 (0.08)
0.25 (0.08)
0.76 (0.13)
1.35 (0.20)
0.81
Q3
I have a backache
0.77 (0.06)
1.40
−0.17 (0.05)
0.71 (0.06)
2.12 (0.09)
2.94 (0.14)
0.49
Q4
I have migraine headaches (headaches)
0.58 (0.05)
2.40
−0.26 (0.05)
1.10 (0.06)
3.46 (0.12)
5.32 (0.27)
0.41
Heart
0.82
Q5
I worry about many things
2.40 (0.12)
0.40
−0.66 (0.10)
0.09 (0.08)
0.82 (0.12)
1.35 (0.18)
0.83
Q6
I worry frequently
1.84 (0.10)
0.50
−0.63 (0.09)
0.23 (0.07)
0.96 (0.11)
1.46 (0.15)
0.76
Q7
I have a lot on my mind and am not able to enjoy anything
1.09 (0.07)
1.19
−0.38 (0.06)
0.76 (0.07)
1.86 (0.11)
2.54 (0.16)
0.57
Q8
I sigh often
0.80 (0.06)
0.89
−0.85 (0.06)
0.36 (0.06)
1.68 (0.08)
2.37 (0.11)
0.39
Spleen
0.82
Q9
I am fatigued and this is not alleviated by anything
1.76 (0.09)
0.25
−1.14 (0.11)
−0.09 (0.07)
0.72 (0.09)
1.50 (0.14)
0.69
Q10
I have to lie down due to fatigue
0.93 (0.06)
0.61
−1.24 (0.07)
0.02 (0.06)
1.37 (0.08)
2.32 (0.12)
0.60
Q11
My body feels heavy
1.62 (0.08)
0.33
−0.90 (0.09)
−0.11 (0.07)
0.83 (0.09)
1.52 (0.13)
0.55
Q12
I don't have much energy in the morning
1.12 (0.07)
0.83
−0.50 (0.06)
0.46 (0.06)
1.33 (0.09)
2.02 (0.12)
0.47
Lung
0.64
Q13
My stomach rumbles
1.45 (0.08)
0.70
−0.88 (0.09)
0.03 (0.06)
1.46 (0.12)
2.21 (0.18)
0.74
Q14
I feel hungry constantly
1.01 (0.07)
1.29
−0.43 (0.06)
0.77 (0.07)
1.96 (0.11)
2.85 (0.18)
0.58
Q15
I have a runny nose
0.61 (0.05)
1.30
−1.25 (0.06)
0.32 (0.05)
2.34 (0.08)
3.79 (0.15)
0.41
Q16
I get the hiccups
0.48 (0.05)
3.85
−0.09 (0.05)
2.24 (0.07)
5.95 (0.24)
7.30 (0.41)
0.36
Kidney
0.79
Q17
I am absent minded
1.70 (0.09)
0.80
−0.48 (0.08)
0.38 (0.07)
1.25 (0.12)
2.06 (0.20)
0.58
Q18
I am not energetic
1.45 (0.08)
0.98
−0.42 (0.07)
0.63 (0.08)
1.59 (0.13)
2.12 (0.17)
0.53
Q19
My memory has deteriorated
1.01 (0.07)
1.03
−0.34 (0.06)
0.61 (0.06)
1.60 (0.09)
2.25 (0.13)
0.49
Q20
I feel lethargic to the point where I have to lie down
0.96 (0.06)
0.81
−0.58 (0.06)
0.39 (0.06)
1.43 (0.08)
2.00 (0.11)
0.43
FVS: Five Viscera Score, a: item discrimination, b: item difficulty (θ), b1: point of intersection with curve 1 and curve 2, b2: point of intersection with curve 2 and curve 3, b3: point of intersection with curve 3 and curve 4, b4: point of intersection with curve 4 and curve 5, and SE: standard error. Mean b is the average of 4 item difficulty values. Item discrimination represents the ability of an item to differentiate the subjects. Overall Cronbach’s α 0.91.
