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Biomedical subjects

Julian Thumboo

Publications and source records attributed to Julian Thumboo.

At least 19 recordsLinked to original sources

Direct and indirect costs of osteoarthritis in Singapore: a comparative study among multiethnic Asian patients with osteoarthritis.

OBJECTIVE: To estimate and compare the direct and indirect costs of osteoarthritis (OA) in multiethnic Asian patients with OA in Singapore. METHODS: The study was a retrospective and cross-sectional design. Patients were stratified according to ethnicity and presence or absence of joint surgery. Direct costs were estimated from both a societal and a patient perspective using the Singapore General Hospital database; indirect costs were estimated using the human capital approach. All costs were expressed as mean costs per patient per annum in 2003 Singapore dollars. RESULTS: A total of 1179 patients (83.6% Chinese, 7.2% Malay, 3.5% Indian, 5.7% others) were included in estimating direct costs, of which 513 (43.5%) had total knee replacement (TKR) and 92 (7.8%) total hip replacement (THR), while 105 patients (71.4% Chinese, 14.3% Malay, 14.3% Indian) were included in estimating indirect costs. Direct costs to patients ranged from 1460 dollars to 7477 dollars for Chinese, 1362 dollars-7211 dollars for Malays, 1688 dollars-6226 dollars for Indians, and 1437 dollars-12,140 dollars for other ethnic patients; direct costs to society ranged from 3351 dollars to 15,799 dollars for Chinese, 2939 dollars-15,436 dollars for Malays, 3150 dollars-10,990 dollars for Indians, and 2597 dollars-17,879 dollars for other ethnic patients. In contrast, the indirect costs ranged from 1215 dollars to 3834 dollars for Chinese, 1138 dollars-6116 dollars for Malays, and 1371 dollars-5292 dollars for Indians. However, most ethnic variations were not statistically significant. CONCLUSION: The economic burden of OA to society and patients increased by 3-fold or more in the patients with TKR/THR compared to those without. The ethnic differences in health resources consumed were more apparent when the disease progressed.

Aged↗

Are Asians comfortable with discussing death in health valuation studies? A study in multi-ethnic Singapore.

BACKGROUND: To characterize ease in discussing death (EID) and its influence on health valuation in a multi-ethnic Asian population and to determine the acceptability of various descriptors of death and "pits"/"all-worst" in health valuation. METHODS: In-depth interviews (English or mother-tongue) among adult Chinese, Malay and Indian Singaporeans selected to represent both genders and a wide range of ages/educational levels. Subjects rated using 0-10 visual analogue scales (VAS): (1) EID, (2) acceptability of 8 descriptors for death, and (3) appropriateness of "pits" and "all-worst" as descriptors for the worst possible health state. Subjects also valued 3 health states using VAS followed by time trade-off (TTO). The influence of sociocultural variables on EID and these descriptors was studied using univariable analyses and multiple linear regression (MLR). The influence of EID on VAS/TTO utilities with adjustment for sociocultural variables was assessed using MLR. RESULTS: Subjects (n = 63, 35% Chinese, 32% Malay, median age 44 years) were generally comfortable with discussing death (median EID: 8.0). Only education significantly influenced EID (p = 0.045). EID correlated weakly with VAS/TTO scores (range: VAS: -0.23 to 0.07; TTO: -0.14 to 0.11). All subjects felt "passed away", "departed" and "deceased" were most acceptable (median acceptability: 8.0) while "sudden death" and "immediate death" were least acceptable (median acceptability: 5.0). Subjects clearly preferred "all-worst" to "pits" (63% vs. 19%, p < 0.001). CONCLUSION: Singaporeans were generally comfortable with discussing death and had clear preferences for several descriptors of death and for "all-worst". EID is unlikely to influence health preference measurement in health valuation studies.

Adult↗

A study of the construct validity of the Health Utilities Index Mark 3 (HUI3) in patients with schizophrenia.

This study assessed the construct validity of the Health Utilities Index Mark 3 (HUI3) in patients with schizophrenia. Patients with schizophrenia recruited from a tertiary mental hospital in Singapore completed the HUI3, the Short-Form 36 Health Survey (SF-36) and the Schizophrenia Quality of Life Scale (SQLS). Patients were assessed for presence and absence of 22 common psychiatric symptoms. Construct validity was assessed using 6 a priori hypotheses. Two hundred and two patients (mean age: 37.8 years, female: 52%) completed the survey. As hypothesized, overall HUI3 utility scores were correlated with SF-36 measures (Spearman's rho: 0.19 to 0.51), SQLS scales (Spearman's rho: -0.56 to -0.36), and the number of psychiatric symptoms (Spearman's rho: -0.49). The HUI3 emotion attribute was moderately correlated with SF-36 mental health (Spearman's rho: 0.45) and SQLS psychosocial scales (Spearman's rho: -0.43), and HUI3 pain attribute was strongly correlated with SF-36 bodily pain scale (Spearman's rho: 0.58). The mean HUI3 overall, emotion, cognition, and speech scores for patients with schizophrenia were 0.07, 0.09, 0.04 and 0.04 points lower than respective age-, sex- and ethnicity-adjusted population norms (p<0.001 for all, ANCOVA). This study provides evidence for the construct validity of the HUI3 in patients with schizophrenia.

Adult↗

Quality of life scores differed according to mode of administration in a review of three major oncology questionnaires.

OBJECTIVE: To assess whether scores on the three major quality-of-life questionnaires in oncology (FACT-G, FLIC, and EORTC QLQ-C30) are associated with modes of administration in a realistic clinical research setting. STUDY DESIGN AND SETTING: A heterogeneous sample of 1,265 cancer patients was recruited in Singapore. About one-fourth of the patients chose to have the interview administered by research staff; the rest self-completed the questionnaires. Multiple regression was used to adjust for differences in demographic and clinical characteristics between patients. An equivalence margin was defined as 0.25 standard deviations. RESULTS: Apart from one exception (the EORTC QLQ-C30 global functioning scale), all scales showed higher mean values in patients who were interviewed than patients who self-administered the questionnaires. For the physical and functional well-being scales of FACT-G and the physical and social functioning scales of EORTC QLQ-C30, the differences were small and the confidence intervals fell totally within the equivalence zone. The emotional well-being score of the FACT-G was different across modes of administration and the confidence interval fell outside the equivalence zones. There was no interaction between modes of administration and respondents' education level. CONCLUSION: The physical aspect of quality-of-life is not sensitive to interviewer administration but the psychological aspect is. Statistical adjustment for some scales is recommended.

Adult↗

Recurrent aortic aneurysms following thoracic aortic stent-graft repair in a patient with Cogan syndrome.

PURPOSE: To report the need for multiple surgical interventions to treat recurrent aortic aneurysms in a patient with Cogan syndrome. CASE REPORT: A 17-year-old Chinese man with clinical Marfanoid features had a left common carotid artery pseudoaneurysm electively repaired with an autologous saphenous vein graft. Four months later, he presented with acute chest pain. Computed tomography (CT) revealed a 1-cm pseudoaneurysm at the mid descending aorta; a 24 x 100-mm Talent stent-graft was implanted to exclude the pseudoaneurysm. He was also found to have increasing left-sided hearing loss. A month later, the patient was re-admitted with vertigo and keratitis, which were treated appropriately. Nine months following stent-graft insertion, he was admitted with acute hemoptysis. Urgent CT showed a rupture at the proximal end of the stent-graft, with hemorrhage into the lung parenchyma. In an emergent procedure, the stent-graft was removed, and the descending thoracic aorta was repaired. Intraoperatively, a large pseudoaneurysm was found arising from the proximal part of the stented aorta, which appeared thickened. His postoperative recovery was uneventful. Nine months after the thoracotomy, a routine CT revealed an aneurysm at the distal descending thoracic aorta. On re-thoracotomy, a de novo saccular aneurysm was found 2.5 cm from the distal anastomosis. The affected segment was replaced with a Dacron graft. The distal aorta appeared thickened and edematous; histology confirmed aortitis. The patient was subsequently diagnosed with Cogan syndrome and given corticosteroids and methotrexate. There is no evidence of recurrence at nearly 2 years after the last intervention. CONCLUSION: This case highlights the pitfalls of stent-graft repair in a patient with presumed connective tissue disease.

Aneurysm, False↗

Developing health-related quality-of-life instruments for use in Asia: the issues.

About half of the world's population live in Asia. Mandarin (the official language of China), Hindi and Japanese are among the ten languages spoken by the largest number of primary speakers. The numbers of Tamil and Malay speakers are expected to grow rapidly in the next few decades. Most health-related quality-of-life (HR-QOL) instruments currently used in Asia are translations and/or adaptations of instruments developed in North America and Western Europe. We illustrate and discuss several major issues in the development of HR-QOL instruments for use in Asia. We have seen insufficient quality in translation and semantic equivalence, which is not a uniquely Asian problem. This problem will be alleviated by putting recently proposed guidelines for translation and adaptation of patient-reported outcomes into practice and formally conducting equivalence studies. For copyright or other reasons it is rare to see major adaptations, such as exclusion of a domain in the original instrument or inclusion of a new domain, made to existing instruments. Evidence is limited and mixed as to whether there are differences in the concepts of HR-QOL between Asian and North American/Western European cultures that are important enough to justify such major adaptations, or the development of indigenous instruments, as opposed to the translation/adaptation of existing instruments. There are substantial cultural differences concerning what questions are appropriate to ask and answer. Many HR-QOL instruments are designed for self-completion. This mode of administration is often not feasible in Asia because of low literacy rates and the presence of many different regional languages. Alternative administration methods and analytic strategies that allow for pooling data collected by different modes are needed. The availability of HR-QOL instruments in various Asian countries seems to reflect the status of economic development of the countries rather than their disease burden. For instance, many important HR-QOL instruments are available in Japanese but not in Hindi or Tamil.

Asia↗

Variability and sample size requirements of quality-of-life measures: a randomized study of three major questionnaires.

PURPOSE: To compare the variability and sample size requirements of the global quality-of-life (QOL) scores of the following three major QOL instruments: the Functional Assessment of Cancer Therapy-General (FACT-G), Functional Living Index-Cancer (FLIC), and European Organisation for Research and Treatment of Cancer Core Quality of Life Questionnaire C30 (EORTC QLQ-C30). PATIENTS AND METHODS: Cancer patients were randomly assigned to answer two of the three instruments using an incomplete block design (n = 1,268). The instruments were compared in terms of coefficient of variation, effect size in detecting a difference between patients with different performance status, and correlation coefficient between scores at baseline and follow-up. RESULTS: The FACT-G and FLIC had significantly smaller coefficients of variation than the EORTC QLQ-C30 (both P < .05). The FLIC also had significantly larger correlation coefficients between scores at baseline and follow-up than the EORTC QLQ-C30 (P < .05). The FACT-G and the FLIC had a larger effect size in a cross-sectional and longitudinal setting, respectively, than the EORTC QLQ-C30 in differentiating patients with different performance status (both P < .05). CONCLUSION: In some aspects, the FACT-G and FLIC global QOL scores had smaller variability and larger discriminative ability than the EORTC QLQ-C30. Further research using other criteria to compare the three instruments is recommended.

Female↗

Order effects: a randomised study of three major cancer-specific quality of life instruments.

BACKGROUND: In methodological studies and outcomes research, questionnaires often comprise several health-related quality of life (HRQoL) measures. Previous psychological studies have suggested that changing the sequential order of measurement scales within a questionnaire could alter the pattern of responses. Yet, information on the presence or absence of order effects on the assessment of HRQoL in cancer patients is limited. METHODS: An incomplete block design was used in this study of 1277 cancer patients. Each patient filled out a questionnaire package that contained two of the three major cancer-specific HRQoL instruments, namely the Functional Assessment of Cancer Therapy--General, the European Organization for the Research and Treatment of Cancer Core Quality of Life Questionnaire and the Functional Living Index--Cancer. Within a questionnaire package the sequential order of the instruments contained were randomised. Measurement properties of the instruments, including the number of missing values, mean HRQoL scores, known-groups validity and internal consistency were compared between samples of different presentation orders. RESULTS: No effect of presentation order on the four properties aforementioned was found. CONCLUSION: Presentation order is unlikely to alter the responses to these HRQoL instruments administered in cancer patients when any two of them are used together.

Activities of Daily Living↗

The impact of diabetes mellitus and other chronic medical conditions on health-related Quality of Life: is the whole greater than the sum of its parts?

BACKGROUND: Diabetes mellitus (DM) is an important public health concern, the impact of which is increased by the high prevalence of co-existing chronic medical conditions among subjects with DM. The aims of this study were therefore to (1) evaluate the impact of DM and co-existing chronic medical conditions on health-related quality of life (HRQoL) (which could be additive, synergistic or subtractive); (2) to determine the extent to which the SF-6D (a single-index preference measure) captures the multidimensional information provided by the SF-36 (a profile measure). METHODS: Using data from a cross-sectional, population-based survey of Chinese, Malay and Indians in Singapore, we developed 9 separate multiple linear regression models, with each SF-36 scale or SF-6D index score being the dependent variable for one model. The influence of DM and a second chronic medical condition (hypertension (HTN), heart disease (HD), musculoskeletal illnesses (MS)) and their interactions were studied after adjusting for the influence of potential confounding variables. RESULTS: Among 5,224 subjects, the prevalence of DM, HTN, HD and MS were 5.9%, 10.7%, 2.4% and 26.6% respectively. DM lowered SF-36 scores by more than 2 points on 3 SF-36 scales and lowered SF-6D scores by 0.03 points. Subjects with DM and HTN, DM and HD or DM and MS experienced further lowering of SF-36 scores exceeding 2 points on at least 6 scales and further lowering of SF-6D scores by 0.05, 0.08 and 0.10 points respectively. Generally, DM and co-existing medical conditions exerted additive effects on HRQoL, with the exception of DM and heart disease, where a subtractive effect was noted. SF-6D index scores generally reflected the patterns of influence of DM and chronic medical conditions on SF-36 scores. CONCLUSION: DM and chronic medical conditions generally reduced HRQoL in this multiethnic general population in an additive, rather than synergistic or subtractive fashion. In this study, the SF-6D was a reasonably good summary measure for the SF-36.

Adult↗

Does being bilingual in English and Chinese influence changes in quality of life scale scores? Evidence from a prospective, population based study.

BACKGROUND: Bilinguals differ from monolinguals in language use, but the influence of bilingualism on changes in Health-Related Quality of Life (HRQoL) scores is not known. OBJECTIVE: To determine the influence of bilingualism on changes in HRQoL scores. RESEARCH DESIGN: A prospective cohort study of a population-based, disproportionately stratified random sample of monolingual or bilingual ethnic Chinese who completed the Short-Form 36 Health Survey (SF-36) in English or Chinese twice in 2 years. Least squares regression models were used to assess the influence of bilingualism on SF-36 scores, while adjusting for the influence of questionnaire language and determinants of HRQoL. RESULTS: Usable English and Chinese questionnaires were returned by 1013 and 910 subjects respectively (aged 21-65 years, 48.5% female, 52.8% bilingual). Bilinguals differed from monolinguals in known determinants of HRQoL (being younger and better educated), changes in determinants of HRQoL over 2 years (more bilinguals had changes in work or marital status) and had mean SF-36 scores that were up to 10 points higher than monolinguals. After adjusting for these differences, bilingualism did not influence 2 year change scores for any of 8 SF-36 scales. CONCLUSION: Bilingualism did not influence changes in HRQoL scores over 2 years in this large, population-based study of subjects fluent in English and/or Chinese (representing an alphabet and/or pictogram based language respectively).

Adult↗

Do health-related quality-of-life domains and items in knee and hip osteoarthritis vary in importance across social-cultural contexts? A qualitative systematic literature review.

OBJECTIVES: To identify and summarize the existing literature on domains/items of health-related quality of life (HRQoL) that are important for patients with knee or hip osteoarthritis (OA) in various sociocultural contexts and critically evaluate existing OA-specific HRQoL instruments based on the important domains/items identified. METHODS: A qualitative systematic literature review was performed using (1) an electronic search of Medline, PsycINFO, ISI Web of Knowledge, and the Cochrane Library (using 29 relevant keywords), and (2) a manual search of relevant journals, textbooks, and bibliographies. Titles and abstracts were reviewed using predefined criteria to select potential articles for full text review. RESULTS: From 20,768 reviewed references, 77 articles were selected for full text review, of which 15 articles fulfilled inclusion criteria. Studies were conducted in English (4 each in the United States and Canada, 2 in the United Kingdom, and 1 in Ireland), French (n = 2), and Swedish (n = 2). Important HRQoL domains in 1 or more countries included pain, physical disability, sports/recreational activities, other symptoms of OA, mental health, social health, and knee/hip-related quality of life. Items within each domain varied from country to country except some physical disability items. The paucity of available information did not allow adequate assessment of OA-specific instruments coverage of important domains/items in various sociocultural contexts. CONCLUSIONS: A surprisingly sparse literature reports the important HRQoL domains/items from the perspective of patients with knee or hip OA. Additional studies are needed to determine the important domains/items for these patients and to confirm that OA-specific measures are truly accurate and comprehensive when applied in various sociocultural contexts.

Culture↗

The equivalence and difference between the English and Chinese versions of two major, cancer-specific, health-related quality-of-life questionnaires.

BACKGROUND: English and Chinese are two of the most widely used primary languages in the world. Patients in many cancer centers have a variety of ethnic backgrounds and primary languages. The comparability of version 4 of the English and Chinese versions of the Functional Assessment of Cancer Therapy-General (FACT-G) and version 3 of the European Organization for the Research and Treatment of Cancer Core Quality of Life Questionnaire (EORTC QLQ-C30) have not been established. METHODS: In total, 1136 ethnic Chinese patients with cancer were recruited from the National Cancer Centre of Singapore. Patients chose to answer an English or Chinese questionnaire, according to their own preference. Multiple regression analysis was used to adjust for differences in demographic and health characteristics. Equivalence was confirmed if the 90% confidence intervals of the adjusted mean difference fell completely within an equivalence zone of +/- 0.25 standard deviations (SD). RESULTS: The English and Chinese versions of the Total, Emotional, and Functional Well Being Scales of the FACT-G and the Physical and Emotional Functioning Scales of the EORTC QLQ-C30 were equivalent. Scores for the other scales on the two questionnaires, at most, had a small differences that did not exceed 0.5 SD. Nevertheless, the Chinese translation of the question "I have a lack of energy" in the Physical Well Being Scale of the FACT-G produced results that differed from the results produced by the original English version. CONCLUSIONS: Data collected from English-speaking and Chinese-speaking respondents were capable of being pooled, and either version could be used for bilingual respondents. Nevertheless, the authors recommend modification of the Physical Well Being question that produced different results ("I have a lack of energy").

Asian People↗

Does the 12-item General Health Questionnaire contain multiple factors and do we need them?

BACKGROUND: The 12-item General Health Questionnaire (GHQ-12) is widely used as a unidimensional instrument, but factor analyses tended to suggest that it contains two or three factors. Not much is known about the usefulness of the GHQ-12 factors, if they exist, in revealing between-patient differences in clinical states and health-related quality of life. METHODS: We addressed this issue in a cross-sectional survey of out-patients with psychological disorders in Singapore. The participants (n = 120) completed the GHQ-12, the Beck Anxiety Inventory, and the Short-Form 36 Health Survey. Confirmatory factor analysis was used to compare six previously proposed factor structures for the GHQ-12. Factor scores of the best-fitting model, as well as the overall GHQ-12 score, were assessed in relation to clinical and health-related quality of life variables. RESULTS: The 3-factor model proposed by Graetz fitted the data better than a unidimensional model, two 2-factor models, and two other 3-factor models. However, the three factors were strongly correlated. Their values varied in a similar fashion in relation to clinical and health-related quality of life variables. CONCLUSIONS: The 12-item General Health Questionnaire contains three factors, namely Anxiety and Depression, Social Dysfunction, and Loss of Confidence. Nevertheless, using them separately does not offer many practical advantages in differentiating clinical groups or identifying association with clinical or health-related quality of life variables.

Adult↗

Validity and reliability of the PDQ-39 and the PDQ-8 in English-speaking Parkinson's disease patients in Singapore.

The purpose of the study was to assess the validity and reliability of the Parkinson's disease questionnaire (PDQ-39, UK English version) as well as its briefer version (the PDQ-8) among Asian patients with Parkinson's disease (PD) in Singapore. Eighty-eight patients recruited from movement disorder clinics or patient support groups completed the PDQ-39 and EQ-5D, a generic health related quality of life questionnaire previously validated for use in Singapore. PDQ-39 items showed good convergent and discriminant validity. Construct validation against the EQ-5D showed strong correlation between these scales as hypothesised (Spearman's rho: 0.53-0.71, P<0.001 for all). Factor analysis yielded a component on which all eight PDQ-39 dimensions were substantially loaded (loading range: 0.50-0.79). The PDQ-39 also demonstrated acceptable internal consistency (Cronbach's alpha: 0.59-0.94) and test-retest reliability (intra-class correlation coefficient:0.67-0.87, n=68). Six of eight PDQ-8 items showed the strongest correlation with their PDQ-39 dimensions as hypothesised. PDQ-39 and PDQ-8 summary indexes were highly correlated (Pearson's r=0.96, ICC=0.95), and both were strongly correlated with the EQ-5D utility index and EQ-5D visual analogue scale (P<0.001). We conclude that the PDQ-39 and PDQ-8 are valid and reliable disease-specific HRQoL instruments for PD in Singapore.

Adult↗

Are English- and Chinese-language versions of the SF-6D equivalent? A comparison from a population-based study.

OBJECTIVE: The goal of this study was to assess the equivalence of English- and Chinese-language versions of the SF-6D (a 6-dimensional health classification system based on the 36-Item Short Form Health Survey) using a model of equivalence proposed previously. METHODS: We analyzed data from a previously published, cross-sectional, population-based survey of ethnic Chinese in Singapore, using linear regression models to adjust for the influence of potential confounding variables. Based on equivalence clinical trial methods, measurement (ie, scale) and item equivalence were assessed by comparing 90% CIs of differences in scores due to language with predefined equivalence margins, that corresponded to the minimum clinically important difference for SF-6D utility and item scores. RESULTS: Data from 2,558 respondents (aged 21-65 years; 48.8% completed the English-language version) were analyzed. The utility scores of respondents using the English- or Chinese-language versions of the SF-6D had similar distribution patterns, with a mean (SD) utility score of 0.8 (0.12). Adjusted 90% CIs for differences in utility and item scores due to language fell within predefined equivalence margins, suggesting measurement and item level equivalence. The 90% CI for scale scores was -0.0089 to 0.0065 (range, 0.0154; equivalence margin, 0.033); the 90% CI for item scores varied from -0.0046 to -0.0020 (range, 0.0026; equivalence margin, 0.0036) for vitality to -0.0024 to 0.0037 (range, 0.0061; equivalence margin, 0.0088) for social functioning. Functional equivalence was suggested because the various aspects of equivalence proposed previously were demonstrated in this study. CONCLUSIONS: English- and Chinese-language versions of the SF-6D demonstrated item, measurement, and functional equivalence in this population-based study comparing 2 widely used languages with very different linguistic structures. This suggests that English and Chinese SF-6D scores can be pooled, thus increasing the representativeness and power of studies using the SF-6D, and providing a basis for studies to value health by obtaining SF-6D utility scores in Asian populations.

Adult↗

Factors influencing health-related quality of life of Asians with anxiety disorders in Singapore.

As little is known about health-related quality of life (HRQoL) in Asians with anxiety disorders, we assessed HRQoL in Singaporeans with anxiety disorders and identified factors influencing their HRQoL. Outpatients with anxiety disorders (n = 119) attending a hospital psychiatric clinic completed the Short Form 36 Health Survey (SF-36), Beck Anxiety Inventory (BAI) and General Health Questionnaire (GHQ-12). SF-36 score reduction from population norms (quantified as the number of standard deviations below the mean) in these subjects was compared with existing data on Singaporeans with various medical conditions and Americans with panic disorder (PD). Factors influencing HRQoL were examined using stepwise multiple linear regression models. SF-36 score reduction in these subjects (0.3-1.4 SD) was greater than that in Singaporeans with systemic lupus erythematosus or thyroid cancer survivors for seven scales but similar to that in Americans with PD (0.5-1.7 SD). BAI and GHQ-12 scores, presence of PD/generalized anxiety disorder, presence of chronic medical conditions, being married or increasing age accounted for 19-61% of the variance in six selected SF-36 scales. In conclusion, it can be said that Singaporeans with anxiety disorders experience clinically important reductions in HRQoL; both clinical and socio-demographic factors influence HRQoL in such subjects.

Adolescent↗