Reliability and Validity of the English-, Chinese- and Malay-Language Versions of the World Health Organization Quality of Life (WHOQOL-BREF) Questionnaire in Singapore

<p><b>INTRODUCTION</b>The World Health Organization Quality of Life (WHOQOL-BREF) questionnaire is a 26-item questionnaire that evaluates 4 domains of quality of life (QoL), namely Physical, Psychological, Social Relationships and Environment. This study aimed to evaluate the validity and reliability of the WHOQOL-BREF among Singapore residents aged 21 and above.</p><p><b>MATERIALS AND METHODS</b>We recruited participants from the general population by using multistage cluster sampling and participants from 2 hospitals by using convenience sampling. Participants completed either English, Chinese or Malay versions of the WHOQOL-BREF and the EuroQoL 5 Dimension 5 Levels (EQ-5D-5L) questionnaires. Confirmatory factor analysis, known-group validity, internal consistency (Cronbach's alpha) and test-retest reliability using the intraclass correlation coefficient (ICC) were performed.</p><p><b>RESULTS</b>Data from 1316 participants were analysed (Chinese: 46.9%, Malay: 41.0% and Indian: 11.7%; 57.5% mean, mean standard deviation [SD, range] age: 51.9 [15.68, 24 to 90] years); 154 participants took part in the retest in various languages (English: 60, Chinese: 49 and Malay: 45). Tucker-Lewis Index (TLI) was 0.919, 0.913 and 0.909 for the English, Chinese and Malay versions, respectively. Cronbach's alpha exceeded 0.7 and ICC exceeded 0.4 for all domains in all language versions.</p><p><b>CONCLUSION</b>The WHOQOL-BREF is valid and reliable for assessing QoL in Singapore. Model fit is reasonable with room for improvement.</p>

A new population-based reference for gestational age-specific size-at-birth of Singapore infants

<p><b>INTRODUCTION</b>There is currently a lack of representative data for local gestational age-specific size-at- birth percentile charts. Existing charts also suffer from limitations relating to the measurement of gestational age (GA) and an outdated population. We aim to construct reference values and charts for size-at-birth from 35 to 41 weeks, based on the healthy local population.</p><p><b>MATERIALS AND METHODS</b>Prospective observational birth cohort study which recruited pregnant mothers from the 2 major public hospitals with obstetric service in Singapore, at <14 weeks gestation and data was collected for birth weight, length and head circumference of infants born from November 2009 to May 2011. Percentile curves were created separately for male and female infants using the lambda-mu-sigma (LMS) method. The new percentile curves were then compared with other internationally published growth charts.</p><p><b>RESULTS</b>Smoothened curves for birth weight, length and head circumference centiles were created from 863 infants (460 males, 403 females). Male infants consistently exceeded female infants in all 3 variables at each GA. For a male and female Singapore infant at 38 weeks gestation, the 10-50-90th centile values for weight would be 2663-3096-3597 vs. 2571-2966-3417 grams, for length 46.4-48.6-51.1 vs. 45.6-48.0-50.4 cm, and for head circumference 32.0-33.5-35.2 vs. 31.4-32.9-34.6 cm. There was no statistically significant difference between ethnic groups. On comparing our birth weight curves with data from Finland across all gestations, birth weights in our term infants (GA ≥37 weeks) were found to be lower across the 10-50-90th percentiles.</p><p><b>CONCLUSION</b>The new centile charts in this study may be used as reference charts for size-at-birth for a subgroup of near-term and term infants. The use of foreign charts may lead to misclassification of small for gestational age (SGA) or large for gestational age (LGA) infants.</p>

Height and mental health and health utility among ethnic Chinese in a polyclinic sample in Singapore

<p><b>INTRODUCTION</b>Whether fi nal height is associated with quality of life and mental health is a matter of epidemiological and medical concern. Both social and biological explanations have been previously proposed. This study aims to assess the associations in ethnic Chinese in Singapore.</p><p><b>MATERIALS AND METHODS</b>A cross-sectional study of 4414 respondents aged at least 21 years seen at a major polyclinic was performed. Socioeconomic and behavioural features of the sample and the Singapore population of similar ages were comparable. Height was measured by clinic nurses using an ultrasonic height senor. Participants were interviewed for socioeconomic, behavioural, health and quality of life information. Clinical morbidity data was collected from the participants' treating physicians. The SF-6D utility index and its Mental Health domain were the main endpoints. Linear and ordinal logistic regression models were used to analyse the utility index and the Mental Health scores, respectively.</p><p><b>RESULTS</b>Having adjusted for age and gender, the Mental Health domain (P <0.01) was associated with height but the utility index was not. Further adjustment for health, socioeconomic and behavioural covariates made little difference. Analyses based on height categories showed similar trends.</p><p><b>CONCLUSION</b>Adult height has a positive association with mental health as measured by the SF-6D among ethnic Chinese in Singapore. Socioeconomic status and known physical health problems do not explain this association. Adult height had no association with SF-6D utility index scores.</p>

Measurement properties of the Chinese language version of the functional assessment of cancer therapy-general in a Singaporean population

<p><b>INTRODUCTION</b>Health-related quality of life is an important aspect of health outcome. The assessment of it must be done by validated instruments. There is no published data on the validity, reliability and sensitiveness to change of the official Chinese translation of the Functional Assessment of Cancer Therapy-General (version 4; FACT-G).</p><p><b>MATERIALS AND METHODS</b>A Chinese questionnaire package comprising the FACT-G and Functional Living Index-Cancer (FLIC, which was translated, modified and validated in Singapore) was filled in by 165 ethnic Chinese patients recruited from the National Cancer Centre, Singapore. Four weeks later, the patients were assessed again by a postal questionnaire survey.</p><p><b>RESULTS</b>The FACT-G and FLIC total scores were strongly correlated (r = 0.85). The Physical, Social/Family, Emotional and Functional Well-being scales of the FACT-G converged to and diverged from FLIC components as conceptually expected. The FACT-G and its 4 scales also demonstrated known-groups validity in differentiating patients with different performance status (each P <0.001). Their internal consistency ranged from 0.81 to 0.93 and test-retest reliability ranged from 0.74 to 0.85. The FACT-G and its Physical, Emotional and Functional Well-being scales showed trends of change in relation to change in performance status. The Social/Family Well-being scale was sensitive to decline but not improvement in performance status.</p><p><b>CONCLUSIONS</b>The Chinese version of the FACT-G can be used to assess overall level and some specific aspects of health-related quality of life. However, researchers should be cautious in using this instrument to specifically investigate the social aspect of quality of life.</p>

Cross-cultural adaptation and validation of Singapore Malay and Tamil versions of the EQ-5D

<p><b>INTRODUCTION</b>The aims of this study were to cross-culturally adapt and evaluate the validity of the Singaporean Malay and Tamil versions of the EQ-5D.</p><p><b>MATERIALS AND METHODS</b>The EQ- 5D was cross-culturally adapted and translated using an iterative process following standard guidelines. Consenting adult Malay- and Tamil-speaking subjects at a primary care facility in Singapore were interviewed using a questionnaire (including the EQ-5D, a single item assessing global health, the SF-8 and sociodemographic questions) in their respective language versions. Known-groups and convergent construct validity of the EQ-5D was investigated by testing 30 a priori hypotheses per language at attribute and overall levels.</p><p><b>RESULTS</b>Complete data were obtained for 94 Malay and 78 Indian patients (median age, 54 years and 51 years, respectively). At the attribute level, all 16 hypotheses were fulfilled with several reaching statistical significance (Malay: 4; Tamil: 5). At the overall level, 42 of 44 hypotheses related to the EQ-5D/ EQ-VAS were fulfilled (Malay: 22; Tamil: 20), with 21 reaching statistical significance (Malay: 9; Tamil: 12).</p><p><b>CONCLUSION</b>In this study among primary care patients, the Singapore Malay and Tamil EQ-5D demonstrated satisfactory known-groups and convergent validity.</p>