Development of a Vietnamese version of the Short form-36 Health Survey

We aimed to test the psychometric properties of a culturally relevant translation of the medical outcomes study short form-36 health survey (SF-36) with prospective Vietnamese migrants. The translated survey was interviewer-administered to 1610 Vietnamese aged over 15 years who had applied to migrate to Australia. All but two SF-36 items had good discriminant validity, and all eight scales of the Vietnamese version of the SFS-36 had good discriminant validity, which supports the use of SF-36 constructs to assess self-reported health status among Vietnamese migrants. However, the mental health, vitality and bodily pain scales demonstrated low internal consistency. This finding is likely to be a product of the increased diversity among scale items following modifications to improve cultural relevance. Further modifications to improve the internal consistency of these scales are required.     

SF-36 health survey reliability, validity and norms for New Zealand

OBJECTIVE: To assess the acceptability, reliability and validity of the SF-36 health survey in the New Zealand population and provide key population norms. METHOD: The SF-36 questionnaire was part of the 1996/97 New Zealand health survey, a cross-sectional, nationally representative survey of 7,862 adults (15 years and over). RESULTS: Overall, in the New Zealand population the questionnaire performed as well as or better than in other national surveys, but there was variability in data completeness across subgroups, and responses were skewed towards the healthy end of the scales. Males scored higher than females on almost all scales; increasing age was associated with decreasing scores (with the exception of the mental health scale); and New Zealand Europeans tended to report better health than the other ethnic groups. CONCLUSIONS: Satisfactory psychometric performance was demonstrated for the SF-36 in the New Zealand population, but researchers need to find ways of increasing data completeness in population groups shown here to have lower completion rates. The questionnaire may be better at discriminating patient rather than population subgroups. The SF-36 normative data confirm in kind, if not in degree, population subgroup disparities in health status observed using objective measures. IMPLICATIONS: Overall, the SF-36 questionnaire appears to be a valid and reliable measure of health-related quality of life for the New Zealand population. However, this paper highlights issues for researchers using the SF-36, such as the skewed nature of responses obstained in a population sample.     

Telephone administration of the SF-36 health survey: validation studies and population norms for adults in Queensland

Abstract: The Rand Corporation medical outcomes short-form 36 health survey (SF-36) is a multidimensional measure of self-perceived general health status, which has been validated in adult populations in the United States and Great Britain, and, more recently, in an Australian population. The SF-36 is increasingly being used in health outcomes research internationally, mainly as a self-administered tool, and clearly has potential for use in Australia. This study aimed to assess the acceptability, reliability and validity of telephone administration of the instrument in the Queensland adult population, and to provide reliable population norms. We report the results of a telephone survey in which we interviewed 12 793 adults. It was the first large-scale, statewide application of the SF-36 in Australia. A response rate of 82 per cent was achieved, and the SF-36 satisfied psychometric criteria for reliability and construct validity. Population norms broken down by age and sex are provided. They will be important for the interpretation of future studies using the SF-36 in particular population or patient groups.     

Is the SF-36 health survey questionnaire suitable as a self-report measure of the health status of older adults with Parkinson's disease?

An amended version of the Short Form 36 health survey questionnaire (SF-36), which has been suggested as being more suitable for self-completion in older adults, was evaluated among a group of elderly subjects with Parkinson's disease (PD). In the subjects who were able to fully complete the modified SF-36 unaided, the severity of PD was broadly reflected by low reported levels of functioning and well-being with this measure. However, the modified questionnaire still did not overcome the problemof missing responses from elderly subjects. A total of 24% of respondents missed one or more of the 36 statements and 80% of missing responses were concentrated in the three statements which had been modified. The SF-36 in its original form would need to be combined with a disease-specific measure to adequately evaluate the health status of older adults with PD.     

The SF-36 in an Australian sample: validating a new,generic health status measure

Abstract: The SF-36 is a self-reported, 36-item, generic measure of health status that has been validated for adult age groups in the United States, the United Kingdom and in some non-English-speaking countries. The Australian Bureau of Statistics used it in the 1995 National Health Survey and it has been used in health status measurement, in monitoring health outcomes and in clinical trials. The validity of the SF-36 was examined in the National Centre for Epidemiology and Population Health Record Linkage Study using a sample of 555 respondents to the National Heart Foundation Risk Factor Prevalence Survey in 1989; they were followed up in 1992. Items chosen for the scale had been used in health status assessment and had stood the test of time. The health concepts measured demonstrated good internal consistency. The eight scales of the SF-36 formed factors as predicted in the general health dimensions of physical and mental health. The component scales of the SF-36 demonstrated good discrimination between people with and without health conditions, including those with medical and those with psychiatric types of conditions. Although the SF-36 was a valid measure of general health status among Australian respondents, further work is needed to establish clinical validity and to produce population norms for Australia. Use of the SF-36 will allow Australian and international comparison of health status from the point of view of the users of health services.     

Evaluation of the SF-36 health index applied to methadone maintenance program users. Reference values for the Basque Autonomous Community, Spain

BACKGROUND: The questionnaires that measure perceived health are used in clinical practice to determine the impact of illnesses and the benefits of treatments. Population-based norms have been proposed to increase their interpretability. The aim of this paper was to obtain reference values for users of Methadone Maintenance Programs (MMP) in the Basque Autonomous Community (BAC). METHODS: Cross-sectional study carried out in 2000 on a stratified random sample of users included in MMP of BAC (n=726). SF-36 Health Survey was used; central trend, dispersion and percentile data were estimated for each of the SF-36 dimension scores to generate reference values according the dwell time in the methadone program. RESULTS: All Cronbach's alpha coefficients were higher than 0.7, and the percentage or non-responds were lower 1%. The MMP users had lower punctuations in all dimensions of SF-36 than population values of reference (p<0.001). The health status of the participants was worse among those than they began the treatment that among those that took more than six months in the MMP; the differences in all SF-36 dimensions scores were statistically significant (p<0.001). CONCLUSIONS: The SF-36 as a measure of health status in MMP population shows a high internal consistence, and is able to discriminate patients with different stages of treatment evolution. Results presented should be considered the population-based norms for monitoring the improvement progression or response to treatment in patients included in MMP.     

Correlations between disease-specific and generic health status questionnaires in patients with advanced COPD: a one-year observational study

ABSTRACT: BACKGROUND: Longitudinal studies analyzing the correlations between disease-specific and generic questionnaires at different time points in patients with advanced COPD are lacking. The aim of this study was to determine whether and to what extent a disease-specific health status questionnaire (Saint George's Respiratory Questionnaire, SGRQ) correlates with generic health status questionnaires (EuroQol-5-Dimensions, EQ-5D; Assessment of Quality of Life instrument, AQoL; Medical Outcomes Study 36-Item Short-Form Health Survey, SF-36) at four different time points in patients with advanced COPD; and to determine the correlation between the changes in these questionnaires during one-year follow-up. METHODS: Demographic and clinical characteristics were assessed in 105 outpatients with advanced COPD at baseline. Disease-specific health status (SGRQ) and generic health status (EQ-5D, AQoL, SF-36) were assessed at baseline, four, eight, and 12 months. Correlations were determined between SGRQ and EQ-5D, AQoL, and SF-36 scores and changes in these scores. Agreement in direction of change was assessed. RESULTS: Eighty-four patients (80%) completed one-year follow-up and were included for analysis. SGRQ total score and EQ-5D index score, AQoL total score and SF-36 Physical Component Summary measure (SF-36 PCS) score were moderately to strongly correlated. The correlation of the changes between the SGRQ total score and EQ-5D index score, AQoL total score, SF-36 PCS, and SF-36 Mental Component Summary measure (SF-36 MCS) score were weak or absent. The direction of changes in SGRQ total scores agreed slightly with the direction of changes in EQ-5D index score, AQoL total score, and SF-36 PCS score. CONCLUSIONS: At four, eight and 12 months after baseline, SGRQ total scores and EQ-5D index scores, AQoL total scores and SF-36 PCS scores were moderately to strongly correlated, while SGRQ total scores were weakly correlated with SF-36 MCS scores. The correlations between changes over time were weak or even absent. Disease-specific health status questionnaires and generic health status questionnaires should be used together to gain complete insight in health status and changes in health status over time in patients with advanced COPD.     

Do the SF-36 and WHOQOL-BREF Measure the Same Constructs? Evidence from the Taiwan Population*

Background: The SF-36 and WHOQOL-BREF are available for international use, but it is not clear if they measure the same constructs. We compared the psychometric properties and factor structures of these two instruments. Methods: Data were collected from a national representative sample (n=11,440) in the 2001 Taiwan National Health Interview Survey, which included Taiwan versions of the SF-36 and WHOQOL-BREF. We used Cronbach’s alpha coefficient to estimate scale reliability. We conducted exploratory factor analysis to determine factor structure of the scales, and applied multitrait analysis to evaluate convergent and discriminant validity. We used standardized effect size to compare known-groups validity for health-related variables (including chronic conditions and health care utilization) and self-reported overall quality of life. Structural equation modeling was used to analyze relationships among the two SF-36 component scales (PCS and MCS) and the four WHOQOL subscales (physical, psychological, social relations, and environmental). Results: Cronbach’s alpha coefficients were acceptable (⩾0.7) for all subscales of both instruments. The factor analysis yielded two unique factors: one for the 8 SF-36 subscales and a second for the 4 WHOQOL subscales. Pearson correlations were weak (<0.3) among subscales of both instruments. Correlations for subscales hypothesized to measure similar constructs differed little from those measuring heterogeneous subscales. Effect sizes suggested greater discrimination by the SF-36 for health status and services utilization known groups, but greater discrimination by the WHOQOL for QOL-defined groups. Structural equation modeling suggested that the SF-36 PCS and MCS were weakly associated with WHOQOL. Conclusions: In this Taiwan population sample, the SF-36 and WHOQOL-BREF appear to measure different constructs: the SF-36 measures health-related QOL, while the WHOQOL-BREF measures global QOL. Clinicians and researchers should carefully define their research questions related to patient-reported outcomes before selecting which instrument to use. * Presented in part at (1) 11th Annual Conference of the International Society for Quality of Life Research. Hong Kong, China, 2004. (2) 2004 Quality of Life Symposium – Conceptualization and Measurement issues in QOL. Tai-Chuan, Taiwan, 2004     

Diabetes-Specific or Generic Measures for Health-Related Quality of Life? Evidence from Psychometric Validation of the D-39 and SF-36

Objective:  There is a debate regarding the use of disease-specific versus generic instruments for health-related quality of life (HRQOL) measures. We tested the psychometric properties of HRQOL measures using the Diabetes-39 (D-39) and the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36).
Methods:  This was a cross-sectional study collecting data from 280 patients in Taiwan. Exploratory factor analysis was conducted to evaluate construct validity of the two instruments. Known-groups validity was examined using laboratory indicators (fasting, 2-hour postprandial plasma glucose, and hemoglobin A1c), presence of diabetic complications (retinopathy, nephropathy, neuropathy, diabetic foot disorder, cardiovascular and cerebrovascular disorders), and psychosocial variables (sense of well-being and self-reported diabetes severity). Overall discriminative power of the two instruments was evaluated using the C-statistic.
Results:  Three distinct factors were extracted through factor analysis. These factors tapped all subscales of the D-39, fourphysical subscales of the SF-36, and four mental subscales of the SF-36, respectively. Compared with the SF-36, the D-39 demonstrated superior known-groups validity for 2-hour postprandial plasma glucose groups but was inferior for complication groups. Compared with the SF-36, the D-39 discriminated better between self-reported severity known groups, but was inferior between well-being groups. In overall discriminative power, the D-39 discriminated better between laboratory known groups. The SF-36, however, was superior in discriminating between complication known groups.
Conclusions:  For psychometric properties, the D-39 and the SF-36 were superior to each other in different regards. The combined use of a disease-specific instrument and a generic instrument may be a useful strategy for diabetes HRQOL assessment.     

The validity of the SF-36 in an Australian National Household Survey: demonstrating the applicability of the Household Income and Labour Dynamics in Australia (HILDA) Survey to examination of health inequalities

Background  

The SF-36 is one of the most widely used self-completion measures of health status. The inclusion of the SF-36 in the first Australian national household panel survey, the Household, Income and Labour Dynamics in Australia (HILDA) Survey, provides an opportunity to investigate health inequalities. In this analysis we establish the psychometric properties and criterion validity of the SF-36 HILDA Survey data and examine scale profiles across a range of measures of socio-economic circumstance.     

A comparison of the responsiveness of different generic health status measures in patients with asthma

Generic health status has been recommended to be measured separately from disease-specific health status, because they can yield complementary information. In particular, generic health status can provide comprehensive health ratings across various disorders. However, the weakness with generic measures is that they may be less responsive to clinical changes than disease-specific ones. Therefore, when using generic health status as an endpoint in clinical trials, the instrument to be used is a problem with respect to responsiveness. In the present study, we investigated and compared the responsiveness of health status measures during asthma treatment using three different generic instruments: the Medical Outcomes Study Short Form 36-items Health Survey (SF-36), the Nottingham Health Profile (NHP) and the EQ5D (EuroQoL), as well as one disease-specific instrument, the Asthma Quality of Life Questionnaire (AQLQ). Fifty-four new patients with asthma who consulted our clinic were recruited. The health status measurements were performed on the initial visit, and at 3 and 6 months. All subscales of the SF-36 showed a significant improvement during the first 6 months. Each dimension of the EQ5D showed stronger ceiling effects than the SF-36. With respect to the responsiveness indices, the SF-36 was regarded as more responsive than the NHP or EQ5D utility. The changes in the SF-36 had a weak to moderate correlation with the changes in the AQLQ. In conclusion, the SF-36 had a higher responsiveness for asthma as a generic measure than the NHP or EQ5D, and evaluated different aspects from the AQLQ. The SF-36 can be used effectively in asthma clinical trials.     

Quality of life in an urban Asian population: the impact of ethnicity and socio-economic status

The relationships between ethnicity, socio-economic status (SES) and health-related quality of life (HRQoL) have not been well characterised in most Asian populations. We therefore studied the influence of ethnicity and SES on HRQoL in a multi-ethnic urban Asian population, adjusting for the influence of other known determinants of HRQoL. In a disproportionately stratified, cross-sectional, population-based survey, Chinese, Malay and Indian subjects in Singapore completed the Short Form 36 Health Survey (SF-36) HRQoL measure and were assessed to determine demographic, socio-economic, psychosocial and other characteristics. Multiple linear regression models were used to study the influence of ethnicity and SES on SF-36 scores while adjusting for the influence of other determinants of HRQoL. The survey participation rate was 92.8%. Ethnic differences in HRQoL were present for all 8 SF-36 scales (p<0.001 for all scales except General Health) among the 4122 Chinese, Malays and Indians surveyed. These ethnic groups also differed in several known determinants of HRQoL (e.g., Chinese had more years of education and Indians had more chronic medical conditions). After adjusting for the influence of these factors, ethnicity and SES independently influenced HRQoL, with mean differences in SF-36 scores due to ethnicity ranging from 1.4 to 13.1 points. Educational level and housing type (markers of SES) were also associated with SF-36 scores (0.5-0.6 point increase per year of education and 3.5-4.0 point increase with better housing type, respectively). Better HRQoL was also associated with better family support, and poorer HRQoL with acute and chronic medical conditions and sick days. The study concludes that ethnicity and SES are associated with clinically important differences in HRQoL in a multi-ethnic, urban Asian population.     

Home telecare for COPD/CHF patients: outcomes and perceptions

We evaluated the use of home telehealth for patients with chronic obstructive pulmonary disease (COPD) and/or congestive heart failure (CHF). Patients diagnosed with COPD and/or CHF who were prescribed home health-care services were randomly assigned to an experimental group where they received home health care through a combination of traditional face-to-face and telemedicine visits (n = 83), and a control group where only conventional home care was employed (n = 78). Data were collected via the Short Form 36 (SF-36), Outcome and Assessment Information Set (OASIS) and patient charts. In the experimental group, patient perceptions of the home telecare services were collected via telephone interviews. Overall, the addition of telehealth to COPD/CHF patient care was not a significant predictor of health and wellbeing, either positively or negatively. Although those receiving telehealth had worse ratings on the SF-36 general health subscale after the intervention, this measure was only significant when controlling for a number of key variables in the model. In regard to patient perceptions of home telecare, patients were satisfied with the technology and the way that care was delivered via this modality.     

Confirmatory factor analysis of the Child Health Questionnaire-Parent Form 50 in a predominantly minority sample

The Child Health Questionnaire-Parent Form 50 (CHQ-PF50; Landgraf JM et al., The CHQ User's Manual. Boston, MA: The Health Institute, New England Medical Centre, 1996) appears to be a useful method of assessing children's health. The CHQ-PF50 is designed to measure general functional status and well-being and is available in several versions to suit the needs of the health researcher. Several publications have reported favorably on the psychometric properties of the CHQ. Landgraf et al. reported the results of an exploratory factor analysis at the scale level that provided evidence for a two-factor structure representing physical and psychosocial dimensions of health. In order to cross-validate and extend these results, a confirmatory factor analysis was conducted with an independent sample of generally healthy, predominantly minority children. Results of the analysis indicate that a two-factor model provides a good fit to the data, confirming previous exploratory analyses with this questionnaire. One additional method factor seems likely because of the substantial similarity of three of the scales, but that does not affect the substantive two-factor interpretation overall.     

A comparison of the Nottingham Health Profile and Short Form 36 Health Survey in patients with chronic lower limb ischaemia in a longitudinal perspective

Background

Different generic quality of life instruments such as the Nottingham Health Profile (NHP) and the Short Form 36 Health Survey (SF-36) have revealed conflicting results in patients with chronic lower limb ischaemia in psychometric attributes in short-term evaluations. The aim of this study was to compare the NHP and the SF-36 regarding internal consistency reliability, validity, responsiveness and suitability as outcome measures in patients with lower limb ischaemia in a longitudinal perspective.

Methods

48 patients with intermittent claudication and 42 with critical ischaemia were included. Assessment was made before and one year after revascularization using comparable domains of the NHP and the SF-36 questionnaires.

Results

The SF-36 was less skewed and more homogeneous than the NHP. There was an average convergent validity in three of the five comparable domains one year postoperatively. The SF-36 showed a higher internal consistency except for social functioning one-year postoperatively and was more responsive in detecting changes over time in patients with intermittent claudication. The NHP was more sensitive in discriminating among levels of ischaemia regarding pain and more able to detect changes in the critical ischaemia group.

Conclusion

Both SF-36 and NHP have acceptable degrees of reliability for group-level comparisons, convergent and construct validity one year postoperatively. Nevertheless, the SF-36 has superior psychometric properties and was more suitable in patients with intermittent claudication. The NHP however, discriminated better among severity of ischaemia and was more responsive in patients with critical ischaemia.

     

Selecting a generic measure of health-related quality of life for use among older adults. A comparison of candidate instruments

Selecting an outcomes assessment instrument requires knowledge of their relative merits, especially head-to-head comparisons. The authors compare health-related quality-of-life (HRQOL) instruments among older adults for their psychometric properties and subject burden, specifically the Sickness Impact Profile (SIP) and Medical Outcomes Study Short-Form 36 (SF-36). Subjects were 282 of 373 eligible older adults (75.6% response) ranging in age from 65 to 96. SIP scores demonstrated a strong skew toward low (good health) scores with a mean of 11.1% (+/- SD 11.5) on the Total SIP index score. Similar components of the SIP and SF-36 were moderately to strongly correlated. The SIP suffered from a ceiling (good health) scaling effect, and the SF-36 scales also demonstrated some scaling extremes. These results demonstrate the relative scaling limits, especially the ceiling effect, of the SIP compared to the SF-36, and in general, the SF-36 is preferred for use among community-living older adults.     

Health outcomes by self-report: validity of the SF-36 among Australian hospital patients

This paper examines the performance of the SF-36 as a self-reported outcome measure in a diverse sample of Australian hospital in-patients. The data derive from the Care Continuum and Health Outcomes Project with a total of 2088 randomly selected patients, yielding a response rate of 80%. Distributions, completion rates and, in particular, correlates of measures were used to investigate the validity of the SF-36 according to clinical and psychometric criteria. Physical functioning, bodily pain, role limitations- physical, general health and vitality scales better represented physical than mental health, with the relative strength decreasing in that order; while mental health, role limitations-emotional and social functioning scales better represented mental health, with the relative strength decreasing in order. A cultural dimension was a strong independent correlate of all scales. While the SF-36 performed satisfactorily, there were weaknesses: the social functioning scale was too narrow to cover social health, both role limitations scales had crude response categories and particular subgroups, the frail elderly and those with complex health conditions, required measures with finer gradings for scales such as physical functioning and bodily pain. Further testing is needed to develop self-reports for use in hospital outcomes measurement which is already proposed in Australia.     

Smoking and functional status among Medicare managed care enrollees

BACKGROUND: Smoking is a major determinant of health status and outcomes. Current smoking has been associated with lower scores on the Short Form-36 Health Survey (SF-36). Whether this occurs among the elderly and disabled Medicare populations is not known. This study assessed the relationships between smoking status and both physical and mental functioning in the Medicare managed-care population. METHODS: During the spring of 1998, data were collected from 134309 elderly and 8640 disabled Medicare beneficiaries for Cohort 1, Round 1 of the Medicare Health Outcomes Survey. We subsequently used these data to calculate mean standardized SF-36 scores, self-reported health status, and prevalence of smoking-related illness, by smoking status, after adjusting for demographic factors. RESULTS: Among the disabled, everyday and someday smokers had lower standardized physical component (PCS) and mental component (MCS) scores than never smokers (-2.4 to -4.5 points; p <0.01 for all). Among the elderly, the lowest PCS and MCS scores were seen among recent quitters (-5.1 and -3.7 points, respectively, below those for never smokers; p <0.01 for both), but current smokers also had significantly lower scores on both scales. For the elderly and disabled populations, MCS scores of long-term quitters were the same as nonsmokers. Similar patterns were seen across all eight SF-36 scales. Ever smokers had higher odds of reporting both less-than-good health and a history of smoking-related chronic disease. CONCLUSIONS: In the elderly and disabled Medicare populations, smokers report worse physical and mental functional status than never smokers. Long-term quitters have better functional status than those who still smoke. More effort should be directed at helping elderly smokers to quit earlier. Smoking cessation has implications for improving both survival and functional status.     

Validation and calibration of the SF-36 health transition question against an external criterion of clinical change in health status

Purpose  Cross-sectional surveys depend on retrospective health transition questions (HTQ) to estimate recent changes in health status. This paper assesses the validity of the SF-36 HTQ and calibrates its categories against change assessed prospectively on the SF-36 domain scales in a sub-group known to have experienced clinically important changes in health status. Methods  Adults (n = 9,649) from a longitudinal population survey completed the SF-36 in 2001 and 2002. Prospective measures were calculated as mean changes in SF-36 scale scores adjusted for age and gender, and also expressed as standardised response means. Comparison groups were those who had developed a long-term health condition since the last interview and the HTQ response categories for those who had not developed any new conditions. Results  Those with a new condition and those without a new condition but who described their health as “somewhat worse” than a year ago had comparable declines in health status on all domain scales except role physical, where those with a new condition experienced a greater decline. Conclusions  This analysis demonstrates the validity and limitations of the HTQ as a measure of change in population studies. The calibration is useful for interpreting the meaning of the HTQ categories at the group level but not at the individual level.