Measurement equivalence of the English, Chinese and Malay versions of the World Health Organization quality of life (WHOQOL-BREF) questionnaires

Table 3 WHOQOL-BREF scales: mean (SD) by language version, equivalence margin and adjusted difference between the two language versions for only ethnic Chinese and ethnic Malay participants

		Ethnic Chinese^c	Ethnic Malay^d
Scale	Equivalence Margin^a	English vs Chinese Difference^b (90% CI)	English vs Malay Difference^b (90% CI)
Physical	±5	−0.73 (−2.94 to 1.48)^†	− 0.39 (− 3.12 to 2.33)^†
Psychological	±5	−2.37 (− 4.73 to − 0.02)^†	− 2.59 (− 4.98 to − 0.20)^†
Social	±5	−1.76 (− 3.86 to 0.35)^†	− 1.99 (− 4.58 to 0.59)^†
Environmental	±5	−1.32 (− 3.53 to 0.89)^†	− 2.90 (− 5.17 to − 0.63)‡

^aApproximately 0.3 SD
^bEnglish minus Chinese, English minus Malay, adjusted for age, sex, education, marital status, smoking status, chronic disease and BMI
^cData from 172 ethnic Chinese participants completed the English version questionnaire and 427 ethnic Chinese participants completed the Chinese version questionnaire
^dData from 114 ethnic Malay participants completed the English version questionnaire and 345 ethnic Malay participants completed the Malay version questionnaire
^†Equivalence confirmed; ^‡Equivalence inconclusive

ISSN: 1477-7525