Cross-cultural adaptation of the SF-36 and SF-12 Physical and Mental Summary Scales on a Chinese Population

Abstractpreprin

Is the standard SF-12 Health Survey valid and equivalent for a Chinese population?

Introduction: Chinese is the world's largest ethnic group but few health-related quality of life (HRQoL) measures have been tested on them. The aim of this study was to determine if the standard SF-12 was valid and equivalent for a Chinese population. Methods: The SF-36 data of 2410 Chinese adults randomly selected from the general population of Hong Kong (HK) were analysed. The Chinese (HK) specific SF-12 items and scoring algorithm were derived from the HK Chinese population data by multiple regressions. The SF-36 PCS and MCS scores were used as criteria to assess the content and criterion validity of the SF-12. The standard and Chinese (HK) specific SF-12 PCS and MCS scores were compared for equivalence. Results: The standard SF-12 explained 82% and 89% of the variance of the SF-36 PCS and MCS scores, respectively, and the effect size differences between the standard SF-36 and SF-12 scores were less than 0.3. Six of the Chinese (HK) specific SF-12 items were different from those of the standard SF-12, but the effect size differences between the Chinese (HK) specific and standard SF-12 scores were mostly less than 0.3. Conclusions: The standard SF-12 was valid and equivalent for the Chinese, which would enable more Chinese to be included in clinical trials that measure HRQoL. © Springer 2005.postprin

Population based norming of the Chinese (HK) version of the SF-36 health survey

Objective: The aim of this study was to establish normative values of the SF-36 Health Survey of the Chinese adult population in Hong Kong so that local references for meaningful interpretation of health-related quality of life (HRQOL) measurements would be available. Design: A cross-sectional telephone survey. Subject: Chinese adults aged 18 years or above randomly selected from the general population in Hong Kong. Main outcome measures: The Chinese (HK) SF-36 Health survey and demographic variables. The normative values of the SF-36 of the general population and different age/sex groups. Results: 2410 subjects completed the survey. The SF-36 scores on Physical Functioning, Role-physical, Bodily Pain and Social Functioning of the study sample were higher but the scores on General Health, Role-emotional and Mental Health were lower than those of the US norms. Age and gender had significant and substantial effects on the SF-36 scores. There was a social class gradient on the General Health, Vitality and Mental Health scores. Other demographic factors had little or no effects on the SF-36 scores. Conclusion: The Chinese (HK) version of the SF-36 is, at present, the only HRQOL measure that has been both validated and normed on Chinese adults in Hong Kong. It can be used as a standard HRQOL instrument to measure the impact of illnesses and the effect of interventions on the quality of life of our Chinese population.published_or_final_versio

Psychometrics and population norm of the Chinese (HK) SF-36 Health Survey_version 2

Objective: To establish the psychometric properties and norm of the Chinese (HK) SF-36 version 2 Health Survey for the adult population in Hong Kong (HK) to facilitate its application and interpretation. Design: A cross-sectional random telephone survey of the general adult population. Subjects: 2410 Chinese adults randomly selected from the general Chinese adult population in Hong Kong. The mean age of the subjects was 42.9 (S.D. 17.3) years, 48% were men and 38% had one or more chronic disease. Main outcome measures: Responses to the SF-36v2 Health Survey questions were extracted. Item-scale correlations, internal and test-retest reliabilities, and the factor structure of the SF-36v2 Health Survey scores were analysed. The SF-36v2 Health Survey scores were calculated by the standard algorithm to establish the population norm. Results: All items had 100% scaling success indicating discriminant validity. Internal consistency and test-retest reliabilities of all scales were good (coefficients 0.66 to 0.89). The hypothesized two-factor structure underlying construction of the physical and mental health summary scales was confirmed. The psychometric properties of the SF-36v2 Health Survey were generally better than version 1. There were significant differences in the population norms between versions 1 and 2 of the Chinese (HK) SF-36 Health Survey, especially in the role-physical and role-emotional scales. Conclusion: The Chinese (HK) SF-36v2 Health Survey is valid and reliable for measuring HRQOL of Chinese adults in Hong Kong, and population norm is now available to support the interpretation of its scores.published_or_final_versio

Tests of scaling assumptions and construct validity of the Chinese (HK) version of the SF-36 Health Survey

Few health-related quality of life (HRQOL) survey instruments are available to the Chinese, although many have been developed for Western populations. This article describes the testing of the acceptability, conceptual equivalence, scaling assumptions and construct validity of a Chinese (HK [Hong Kong]) version of the MOS SF-36 Health Survey. A Chinese (HK) SF-36 survey form was developed by an iterative translation process. It was administered to 236 Chinese subjects who also rated the understanding, difficulty, relevance, and acceptability of each question. The scores were tested against the original scaling assumptions. The SF-36 profile of our subjects was compared to U.S. results for conceptual equivalence. Most subjects did not have any problem in understanding and answering the SF-36. Item means were generally clustered as hypothesized. All but a few items satisfied all scaling assumptions. The shape of the eight-scale SF-36 profile was similar to that of American patients, suggesting conceptual equivalence. We conclude that the Chinese (HK) version of the SF-36 Health Survey has achieved conceptual equivalence and satisfied the psychometric scaling assumptions well enough to warrant further use and testing, using the standard scoring algorithms.postprin

The SF-36 summary scales were valid, reliable, and equivalent in a Chinese population

Objectives: To find out whether the SF-36 physical and mental health summary (PCS and MCS) scales are valid and equivalent in the Chinese population in Hong Kong (HK). Study Design and Setting: The SF-36 data of a cross-sectional study on 2,410 Chinese adults randomly selected from the general population in HK were analyzed. Results: The hypothesized two-factor structure of the physical and mental health summary scales (PCS and MCS) was replicated and the expected differences in scores between known morbidity groups were shown. The internal reliability coefficients of the PCS and MCS scales ranged from 0.85 to 0.87. The effect size differences between the U.S. standard and HK-specific PCS and MCS scores were mostly <0.5. The effect size differences in the standard PCS and MCS scores of specific groups between the U.S. and H.K. populations were all <0.5. Conclusion: The PCS and MCS scales were applicable to the Chinese population in HK. The high level of measurement equivalence of the scales between the U.S. and H.K. populations suggests that data pooling between the two populations could be possible. To our knowledge, this is the first study to show that the SF-36 summary scales are valid and equivalent in an Asian population. © 2005 Elsevier Inc. All rights reserved.postprin

Liposomes and Extracellular Vesicles as Drug Delivery Systems:A Comparison of Composition, Pharmacokinetics, and Functionalization

Over the past decades, lipid-based nanoparticle drug delivery systems (DDS) have caught the attention of researchers worldwide, encouraging the field to rapidly develop improved ways for effective drug delivery. One of the most prominent examples is liposomes, which are spherical shaped artificial vesicles composed of lipid bilayers and able to encapsulate both hydrophilic and hydrophobic materials. At the same time, biological nanoparticles naturally secreted by cells, called extracellular vesicles (EVs), have emerged as promising more complex biocompatible DDS. In this review paper, the differences and similarities in the composition of both vesicles are evaluated, and critical mediators that affect their pharmacokinetics are elucidate. Different strategies that have been assessed to tweak the pharmacokinetics of both liposomes and EVs are explored, detailing the effects on circulation time, targeting capacity, and cytoplasmic delivery of therapeutic cargo. Finally, whether a hybrid system, consisting of a combination of only the critical constituents of both vesicles, could offer the best of both worlds is discussed. Through these topics, novel leads for further research are provided and, more importantly, gain insight in what the liposome field and the EV field can learn from each other

Validation of the Kiswahili version of the SF-36 Health Survey in a representative sample of an urban population in Tanzania

The objective of this study was to assess the validity of a Kiswahili translation of the SF-36 Health Survey (SF-36) among an urban population in Tanzania, using the method of known-groups validation. People were randomly selected from a demographic surveillance system in Dar es Salaam. The representative sample consisted of 3,802 adults (15 years and older). Health status differences were hypothesized among groups, who differed in sex, age, socio-economic status and self-reported morbidity. Mean SF-36 scale scores were calculated and compared using t-test and ANOVA. Women had significantly lower mean SF-36 scale scores (indicating worse health status) than men on all scales and scores were lower for older people than younger on all domains, as hypothesized. On five of the eight SF-36 scales, means were higher for people of higher socio-economic status compared to those of lower socio-economic status. People who reported an illness within the previous 2 weeks scored significantly lower on all scales compared to those who were healthy, as did people who said they had a disability or a chronic conditio

Developing a new version of the SF-6D health state classification system from the SF-36v2: SF-6Dv2

Objective: The objective of this study was to develop the classification system for version of the SF-6D (SF-6Dv2) from the SF-36v2. SF-6Dv2 is an improved version of SF-6D, one of the most widely used generic measures of health for the calculation of quality-adjusted life years. Study Design and Setting: A 3-step process was undertaken to generate a new classification system: (1) factor analysis to establish dimensionality; (2) Rasch analysis to understand item performance; and (3) tests of differential item function. To evaluate robustness, Rasch analyses were performed in multiple subsets of 2 large cross-sectional datasets from recently discharged hospital patients and online patient samples. Results: On the basis of factor analysis, other psychometric evidence, cross-cultural considerations, and amenability to valuation, the 6-dimension classification used in SF-6D was maintained. SF-6Dv2 resulted in the following modifications to SF-6D: a simpler classification of physical function with clearer separation between levels; a more detailed 5-level description of role limitations; using negative wording to describe vitality; and using pain severity rather than pain interference. Conclusions: The SF-6Dv2 classification system describes more distinct levels of health than SF-6D, changes the descriptions used for a number of dimensions and provides clearer wording for health state valuation. The second stage of the study has developed a utility value set using discrete choice methods so that the measure can be used in health technology assessment. Further work should investigate the psychometric characteristics of the new instrument