Table 6.

Total and subscale score of English and Chinese MFSI-SF versions and measurement equivalence between the two versions

(Theoretical Score Range)	Mean ± S.D.			English vs. Chinese
	Total (N = 236)e	English-version (n = 155)	Chinese-version (n = 81)	Equivalence margina (±0.25 S.D.)	Equivalence marginb (±0.5 S.D.)	95% CI of Unadjusted difference	95% CI of Adjusted differencec
Total MFSI-SF score	0.720 (19.06)	1.56 (20.32)	− 0.889 (16.36)	± 4.59	± 9.17	− 2.450 (− 7.599 to 2.698)	0.095 (− 1.512 to 0.097)
General	4.34 (4.51)	4.87 (4.74)	3.33 (3.84)	± 1.07	± 2.15	− 1.538 (− 2.742 to − 0.333)	− 0.009 (− 1.327 to 1.148)
Physical	3.88 (4.11)	4.22 (4.51)	3.22 (3.15)	± 0.96	± 1.91	− 0.997 (− 2.103 to 0.109)	0.023 (− 0.967 to 1.357)
Emotional	3.21 (4.25)	3.34 (4.46)	2.96 (3.83)	± 1.04	± 2.07	− 0.373 (− 1.522 to 0.777)	0.096 (−  0.423 to 2.142)d
Mental	3.00 (3.91)	3.32 (4.28)	2.38 (3.01)	± 0.91	± 1.82	− 0.933 (− 1.985 to 0.118)	− 0.016 (− 1.274 to 1.017)
Vigour	13.70 (6.48)	13.18 (6.61)	12.79 (6.14)	± 1.59	±3.19	− 1.391 (− 3.134 to 0.353)	− 0.217 (− 4.922 to − 0.991)d

MFSI-SF Multidimensional Fatigue Symptom Inventory - Short Form

Equivalence was assessed by comparing 95% CI of the adjusted difference to the equivalence margin (±0.5 S.D.)

^aThe equivalence margin is the simple average of the standard deviation of the Chinese and English scores multiplied by 0.25

^bThe equivalence margin is the simple average of the standard deviation of the Chinese and English scores multiplied by 0.50

^cMean difference between the English and Chinese version was adjusted for relevant variables that showed statistical significant differences between the English and Chinese version of MFSI-SF (Table 1 and Additional file 1: Table S3): age, race (Chinese vs Non-Chinese), education (low education vs high education), ECOG status, EORTC nausea and vomiting symptom, EORTC dyspnoea item

^d95% CI of the adjusted difference exceeded the equivalence margin threshold (±0.5 S.D.)

^eData for ECOG was missing for 10 patients