Cultural adaptation and validation of the Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO) in a Mexican population

Osteoporosis and Fragility Fractures in Mexico: A Call to Action

Osteoporosis (OP) is a chronic disease that affects older adults' quality of life, with fragility fractures (FF) being its most significant consequence due to their impact on healthcare systems in terms of morbidity, and economic and caregiving burden. FF are defined as fractures resulting from low-energy trauma, defined as falls from a standing height or less, and are usually considered osteoporotic (1). World demographic projections warn of a significant increase in adults aged 65 and older by 2050. These demographic changes mean that OP and FF will soon become an even greater challenge for healthcare systems, where prevention programs should be a priority. In Mexico, FF is also a public health challenge, with an initial reported incidence of nearly 2,000 cases per 100,000 population, and a projected seven-fold increase by 2050. Given this scenario, there is an urgent need for policy- and decision-makers to change their approach and formulate health policies that guarantee that people aged 65 and older are screened for fractures and have access to appropriate care. These policies should be part of a strategy to minimize FF and ensure active and healthy aging according to the WHO's Decade of Healthy Ageing. In this context, a group of Mexican experts representing different health organizations interested in the burden of OP and FF met to discuss possible strategies to reduce their burden for the next decade and summarize them in this Call to Action to promote public policies that prioritize an evidence-based approach to the prevention and treatment of OP and FF.

Health-related quality of life in osteoporosis: a systematic review of measurement properties of the QUALEFFO-41

The 41-item Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41) is a widely used and freely available patient-reported outcome measure (PROM). However, data on its reliability, validity, and responsiveness remain unclear. Therefore, this study aimed to systematically review the measurement properties of the QUALEFFO-41. A systematic search of MEDLINE, EBSCOhost, and Cochrane Library from their inception up to December 2022 was performed. Data were extracted, and the methodological quality of each measurement property was evaluated according to the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guidelines. The evidence of the measurement properties was rated against the updated criteria for good measurement properties, and the quality of evidence was graded using the modified GRADE approach. A total of 99 articles were identified, of which eight studies were included in the review. The QUALEFFO-41 is categorized as B as it demonstrated moderate quality evidence for sufficient content validity, moderate-to-high quality evidence for sufficient hypothesis testing for construct validity (except for the social function domain for convergent validity), and very low-quality evidence for sufficient responsiveness. For structural validity and internal consistency, only the domains of pain and general health perception were sufficient with low-quality evidence. For reliability, only the domain of physical function was sufficient with low-quality evidence. None of the studies reported measurement error, cross-cultural validity, and criterion validity. The QUALEFFO-41 may be a promising, valid, and reliable PROM to assess HRQoL in osteoporosis patients with vertebral fractures. However, future studies must focus on good methodological quality to strengthen the evidence of measurement properties, especially on structural validity, reliability, responsiveness, and cross-cultural validity. The systematic review evaluated the measurement properties of the QUALEFFO-41 questionnaire for assessing Health-Related Quality of Life (HRQoL) in osteoporosis patients. The review found moderate-to-high-quality evidence for construct validity but limited evidence for responsiveness and other properties. Future studies should focus on strengthening the evidence, particularly for structural validity, reliability, responsiveness, and cross-cultural validity. The QUALEFFO-41 shows promise as a valid and reliable PROM for HRQoL assessment in osteoporosis patients.

Transcultural adaptation and psychometric properties of the Korean version of the Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41)

We translated and adapted transculturally the Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41) for Korean patients. The translated Korean version of QUALEFFO-41 showed satisfactory reliability and validity.

PURPOSE

The aim of this study was to translate the QUALEFFO-41 for Korean patients and then validate the Korean version of QUALEFFO-41.

METHODS

Translation and transcultural adaptation of the QUALEFFO-41 was conducted according to the international recommendations. Ninety-seven patients (mean age, 73.6 years) with osteoporosis were participated in validating the Korean version of QUALEFFO-41. To test reliability, internal consistency was evaluated using Cronbach's alpha coefficient. To test validity, convergent validity was assessed using correlation with the SF-12 and EQ-5D and discriminant validity was assessed using ROC curve analysis.

RESULTS

The English version of QUALEFFO-41 was translated and adapted to Korean without notable discrepancies. The Korean QUALEFFO-41 had good reliability with Cronbach's alpha ranging from 0.733 to 0.942. QUALEFFO-41 had good correlations to SF-12 and EQ-5D. Compared with subjects without history of vertebral fracture (VF), those with history of VF showed significantly worse scores according to QUALEFFO-41, but not according to SF-12 or EQ-5D. ROC curve analysis revealed that the physical function domain of QUALEFFO-41 had significant ability to discriminate between subjects with and without history of VF, while SF-12 or EQ-5D did not.

CONCLUSIONS

The Korean version of QUALEFFO-41 demonstrated relevant internal consistency, convergent validity, and discriminant validity, which can be recommended to evaluate quality of life in Koreans.

Health-related quality of life in older people with osteoporotic vertebral fractures: a systematic review and meta-analysis

Health-related quality of life in osteoporotic patients with vertebral fracture is of increasing interest, but relevant studies have yielded debatable results. This systematic review and meta-analysis of 16 observational studies demonstrate a clear association between physical health status and presence of vertebral fracture after accounting for age. This meta-analysis was conducted to identify if there are any differences between physical and/or mental health-related quality of life (HRQoL) in older people with osteoporosis based on conventional T-score definitions and the presence or absence of vertebral fracture. A comprehensive search was undertaken using the databases of PubMed, Embase, Medline, Web of Science, and the "grey" literature from 1950 to the end of April 2015. Search terms for vertebral fracture (VF) included VF, osteoporotic fracture, fragility fracture, and spinal fracture. Quality of life was searched using the following terms: quality of life, health-related quality of life, HRQoL, and QoL. Strict inclusion and exclusion criteria were used. The standardized mean difference (SMD) was calculated for each HRQoL domain by the difference in means between case and control groups divided by the pooled SD of participants. Sixteen eligible studies were identified involving 3131 men and women. There was evidence of publication bias and heterogeneity. The meta-analysis showed worse physical (SMD = 0.53, 95 % confidence interval (CI) 0.38 to 0.68; P < 0.001) and mental (SMD = 0.19, 95 % CI 0.05 to 0.33; P = 0.009) HRQoL in osteoporotic older people with vertebral fracture compared to those without fracture. Similar differences were observed for physical HRQoL in further analyses accounting for possible confounding effects of age. Sub-analysis to assess associations between number/severity of fractures and time since fracture was not possible due to small numbers of studies that accounted for age. Osteoporotic older people with vertebral fracture have worse physical HRQoL than osteoporotic older people without vertebral fracture, even after accounting for age differences.

Validation of the simplified Chinese version of the quality of life questionnaire of the European foundation for osteoporosis (QUALEFFO-31)

PURPOSE

To translate quality of life questionnaire of the European foundation for osteoporosis (QUALEFFO-31) into a simplified Chinese version, and test its reliability and validity in osteoporosis patients from mainland Chinese population.

METHODS

Postmenopausal osteoporosis women with history of vertebral fracture were included as cases, and age-matched healthy female were included as controls. All subjects were from mainland China. The simplified Chinese version of QUALEFFO-31 and SF-36 were assigned to the two groups. Reliability was assessed using kappa statistics of agreement for each item and the intra-class correlation coefficient (ICC). The internal consistency was assessed with Cronbach's α. Pearson's correlation was used to assess convergent and discriminant validity.

RESULTS

Overall, 66 cases and 66 age-matched controls were included. The ICC for the test-retest reliability ranged from 0.76 to 0.91. Cronbach's α for pain, physical function, and mental function domains were 0.94, 0.87, and 0.79, respectively. Convergent validity and discriminant validity showed that each correlation coefficient between score of each item with total score of related domain was higher than that with total score of unrelated domain. Pearson's correlation coefficients indicated significantly high correlations between corresponding domains of QUALEFFO-31 and SF-36.

CONCLUSIONS

The simplified Chinese version of the QUALEFFO-31 is a reliable and valid outcome measure of functional status in patients with osteoporosis. This Chinese version of the QUALEFFO-31 can be utilized for future clinical studies in mainland China.

Validation of the Quality of Life Questionnaire of the European Foundation for Osteoporosis-31 in Spanish postmenopausal women

OBJECTIVE

The Quality of Life Questionnaire of the European Foundation for Osteoporosis-31 (QUALEFFO-31) is a reliable and validated questionnaire that assesses quality of life in osteoporotic women. Our objective was to analyze the reliability and validity of the Spanish version of QUALEFFO-31 and its ability to discriminate between women with osteoporosis and women without osteoporosis in a Spanish postmenopausal population.

METHODS

One hundred eighteen women (aged 50-65 y) completed the Spanish version of QUALEFFO-31. Bone mineral density was measured by dual-energy x-ray densitometry. Internal consistency and test-retest reliability were analyzed. Concurrent validity of QUALEFFO-31 was evaluated using Spearman's rank correlation coefficient with the 36-item Short-Form Health Survey (SF-36). To determined responsiveness, we analyzed mean differences between osteoporotic and nonosteoporotic women and performed receiver operating characteristic curve analysis.

RESULTS

The Spanish version of QUALEFFO-31 has shown excellent test-retest reliability with a high intraclass correlation coefficient for all its domains, especially for the total score (0.988; P < 0.001), and good internal consistency with optimal Cronbach α values in all scales (0.70-0.90). In concurrent validity analysis, QUALEFFO-31 total score showed a high and negative correlation with several scales of the SF-36 (P < 0.001). In responsiveness analysis, significant differences in the pain (P = 0.002) and QUALEFFO-31 total score (P = 0.004) scales were found between osteoporotic and nonosteoporotic women. No differences in areas under the receiver operating characteristic curve were found between the QUALEFFO-31 and the SF-36 scales.

CONCLUSIONS

The Spanish version of QUALEFFO-31 has good internal consistency, concurrent validity, and test-retest reliability, with satisfactory general psychometric properties, and is a valid tool for discriminating between osteoporotic and nonosteoporotic postmenopausal women aged 50 to 65 years.

Validation of the Malay version of the Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41) in Malaysia

PURPOSE

To assess the validity and reliability of the Malay version of the Quality of Life (QOL) Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41) in Malaysia.

METHODS

The QUALEFFO-41 was translated from English to Malay and administered to 215 post-menopausal osteoporotic women ≥50 years who could understand Malay, at baseline and 4 weeks. The SF-36 was administered at baseline to assess convergent validity. To assess discriminative validity, patients with and without back pain were recruited.

RESULTS

Confirmatory factor analysis showed that the QUALEFFO-41 had five domains. Good internal consistency was seen in all domains (0.752-0.925) except for the social activity domain (0.692). Test-retest reliability showed adequate correlation for all items (0.752-0.964, p < 0.001). Patients with back pain had significantly worse QOL compared with those without (back pain = 42.2 ± 10.9, no back pain = 33.3 ± 8.9; p < 0.001). The total QUALEFFO-41 score and the SF-36 physical and mental composite scores were significantly correlated (-0.636 and -0.529, p < 0.001, respectively).

CONCLUSIONS

The Malay version of the QUALEFFO-41 was found to be a reliable and valid instrument to evaluate the QOL of osteoporotic patients in Malaysia. To enable the QUALEFFO-41 to be used in a multiracial population, further studies should look into validating other versions of the QUALEFFO-41 in Malaysia.

An outcome measure of functionality and quality of life in Iranian women with osteoporotic vertebral fractures: a validation study of the QUALEFFO-41

BACKGROUND

Osteoporosis is a very common disease and often results in vertebral fractures. The Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41) is a tool to measure health-related quality of life in these patients. This study aimed to cross-culturally translate and validate the QUALEFFO-41 in Iran.

METHODS

This was a prospective clinical validation study. A forward-backward procedure was used to translate the questionnaire from English into Persian. The translation and cross-cultural adaptation were made in accordance with published guidelines. Patients were divided into two study groups according to the World Health Organization criteria: those with at least one vertebral fracture who had undergone surgery and those with osteoporosis and no fractures as a control group. All of the participants were assessed by both the QUALEFFO-41 and SF-36. The surgery group was asked to respond to the QUALEFFO-41 at two points in time: the pre- and postoperative assessments (6-month follow-up). To test reliability, the internal consistency was evaluated using Cronbach's alpha coefficient. Validity was evaluated by assessing convergent validity between the QUALEFFO-41 and SF-36 and item-scale correlations and discriminatory ability. Internal responsiveness of the QUALEFFO-41 to the clinical intervention (surgery) also was evaluated comparing patients' pre- and postoperative scores.

RESULTS

A total of 149 patients completed the questionnaire: 48 surgical patients and 101 as a control group. At the pre- and postoperative assessments, the QUALEFFO-41 showed adequate internal consistency in all domains (Cronbach's alpha of 0.71 to 0.81). Additionally, the correlation of each item with its hypothesized domain on the QUALEFFO-41 indicated acceptable results, suggesting that the items had a substantial relationship with their own domains. Further analysis also indicated that the questionnaire was responsive to change (P < 0.0001). Significant correlations existed between scores of similar subscales of the QUALEFFO-41 and SF-36 (P < 0.001).

CONCLUSIONS

The findings show that the Iranian version of the QUALEFFO-41 is a reliable and valid measure of functionality and quality-of-life evaluation among patients with osteoporotic vertebral fractures.

Validation of the Portuguese version of the quality of life questionnaire of the European foundation for osteoporosis (QUALEFFO-41) in Brazilian women with postmenopausal osteoporosis with vertebral fracture

To validate the Portuguese version of the quality of life questionnaire of the European foundation for osteoporosis (QUALEFFO-41) in Brazilian women with osteoporotic vertebral fractures (VF). A questionnaire validation study of 86 postmenopausal women was conducted. Women were divided into two groups: 43 in a group with VF and 43 in a group without osteoporosis, age-matched (±3 years). The QUALEFFO-41 questionnaire was administered twice in 4 weeks and compared to a generic questionnaire SF-36. For analysis of the QUALEFFO-41, internal consistency, repeatability, and discriminant capacity between VF patients and control patients were assessed. The significance level adopted was 5 %. The mean age of the women was 66.1 ± 7.2 years for the group with VF and 64.9 ± 6.3 years for the control group (p = 0.4259). The QUALEFFO showed adequate internal consistency in all domains (Cronbach's α of 0.74 to 0.84) and good repeatability (ICC of domains = 0.67-0.90). Of the total questions, 92.6 % demonstrated satisfactory convergent validity, and 95 % of the questions showed good discriminant validity. The mean scores of both questionnaires were significantly higher in the group with VF. There was a good correlation among the QUALEFFO-41 domains and their corresponding SF-36 domains, except for social function. All QUALEFFO-41 domains were significantly predictive of VF on assessment of the ROC curve. The Portuguese version of the QUALEFFO-41 may be used in Brazilian women with osteoporotic VF because it shows good reliability, repeatability, and validity. It was also shown to impair quality of life (QOL) in women with VF and had good ability to discriminate QOL in women with osteoporotic VF.

Health-related quality of life in patients with osteoporosis in the absence of vertebral fracture: a systematic review

To review whether osteoporosis in the absence of vertebral fracture (VFX) affects health-related quality of life (HRQoL), a systematic search of the main literature databases for HRQoL in patients with osteoporosis without VFX was undertaken. This was undertaken. This identified 1,327 articles as potentially relevant to the review. After screening of abstracts and reviewing 168 articles in detail, 27 were considered relevant. HRQoL data were extracted and collated into tables and, where possible, were converted into normative scores and further analysed. Data relating to the associations between HRQoL and bone mineral density (BMD) were also collated. Of the 27 articles included, only 5 directly compared osteoporosis without VFX with a control group (BMD T-score > -1.0, without VFX). Extracted raw data from 21 articles demonstrated that patients with osteoporosis without VFX had clinically relevant reductions in role physical, general health, vitality, mental health domains and the mental component summary score, using SF36. Using Qualeffo-41, pain and physical function were worse in these patients. Also, HRQoL was related to upper femur, but not lumbar spine BMD. HRQoL data in patients with osteoporosis without VFX are limited and variable but suggest that HRQoL is adversely affected by osteoporosis in the absence of VFX. The association of lower BMD and worse HRQoL suggests that more attention should be paid to HRQoL in those without VFX. Future studies are needed to investigate HRQoL in patients with osteoporosis in the absence of fracture, controlling for co-morbidities and social and economic status.

Quality of life measurements in patients with osteoporosis and fractures

To review all specific questionnaires regarding quality of life in osteoporosis and to describe their distinctive indications, we searched Medline, the Scientific Electronic Library Online database, and the Latin-American and Caribbean Health Sciences Literature database. Nine specific questionnaires related to osteoporosis quality of life were found: 1) the Women's Health Questionnaire, 2) Osteoporosis Quality of Life Questionnaire, 3) Osteoporosis Assessment Questionnaire, 4) Osteoporosis Functional Disability Questionnaire, 5) Quality of Life Questionnaire of the European Foundation for Osteoporosis, 6) Osteoporosis-Targeted Quality of Life Questionnaire, 7) Japanese Osteoporosis Quality of Life Questionnaire, 8) the 16-item Assessment of Health-Related Quality of Life in Osteoporosis, and 9) the Quality of Life Questionnaire in Osteoporosis (QUALIOST™). The Quality of Life Questionnaire of the European Foundation for Osteoporosis is the osteoporosis-specific questionnaire most commonly used in the literature. The Quality of Life Questionnaire of the European Foundation for Osteoporosis and the Osteoporosis Quality of Life Questionnaire are targeted more toward fracture assessment, and the Osteoporosis Functional Disability Questionnaire can be used for longitudinal studies involving exercise. In the present study, the authors summarize all of the specific questionnaires for osteoporosis and demonstrate that these questionnaires should be selected based on the objectives to be evaluated. Osteoporosis-specific quality of life questionnaires should be validated in the language of the country of origin before being used.

Validation of the osteoporosis quality of life questionnaire QUALEFFO-41 for the Serbian population

Background

Vertebral fractures could lead to reduced physical, social and mental functioning, and loss of personal independence. Therefore, during the treatment of osteoporosis, it has become necessary to examine the changes in everyday functioning, well-being and health related quality of life (HRQOL). To that effect, this study aims to translate, culturally adapt, and validate the Serbian version of Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41) for patients with vertebral fractures.

Methods

Nine female patients with osteoporosis participated in the pre-validation study. A validation, case–control study included two groups of female patients: one that consisted of 50 female patients with osteoporosis, and with at least one vertebral fracture, and another one that consisted of 50 control patients with osteoporosis but without fractures. They completed the QUALEFFO-41 and the EuroQol group questionnaire with five dimensions (EQ-5D) twice within a month. The validation study examined internal consistency, concurrent validity, test-retest reliability, sensitivity and specificity.

Results

During the pre-validation study, three of the items in the QUALEFFO-41 were slightly changed. Afterwards, during the validation study, the statistically significant differences (adjusted for: age, duration of menopause, current employment and marital status) in the mean values of all domains and total scores between the groups were noted. For the case group, the internal consistency of the QUALEFFO-41 domains and of total questionnaire was above 0.70. The test-retest reliability was tested by the intraclass correlation coefficients (ICC) that were in range 0.87 – 0.96 for the case, and 0.15 – 0.83 for the control group. Correlations between the total scores of the QUALEFFO-41 and the EQ-5D health state value, for both groups were negative and statistically significant (r = -0.78, p<0.001 and r = -0.73, p<0.001, respectively). The QUALEFFO-41 had a better prediction of the value of HRQOL of cases compared to the generic questionnaire EQ-5D (the AUC difference was 0.099, p = 0.013).

Conclusions

The Serbian QUALEFFO-41 version is reliable, valid, sensitive and predictive for examinations of HRQOL in patients with prevalent vertebral fractures and can be used in further studies.

Association between generic and disease-specific quality of life questionnaires and mobility and balance among women with osteoporosis and vertebral fractures

BACKGROUND AND AIMS

The aims of this study were to assess correlations between two health-related quality of life (HRQOL) measurements, the Quality of Life Questionnaire issued by the European Foundation for Osteoporosis (QUALEFFO- 41) and the total score of The General Health Questionnaire (GHQ-20) in a population of women living at home with well-established osteoporosis and at least one vertebral fracture, as well as the internal consistency and floor and ceiling effects of these measurements. Also examined were the mean values of these measurements, to ascertain whether they were significantly different for the group consisting of 75% of the women with the best performance on mobility and balance, compared with the other participants.

METHODS

Across-sectional study of 89 women aged 60 years or more, evaluated by QUALEFFO-41 (consisting of one total score and five section scores), GHQ-20 (one total score), maximum speed and Functional Reach (FR).

RESULTS

Cronbach's alpha coefficient for measurements of HRQOL ranged from 0.61 to 0.92. Significant correlations between 'QUALEFFO- 41: total score' and 'GHQ-20: total score' were 0.49, and between 'GHQ-20: total score' and section scores of 'QUALEFFO-41' 0.28-0.63. Those in the 75% group with the highest maximum walking speed or longest distance on FR reported significantly better disease-specific HRQOL than the others, with poorer results on these tests.

CONCLUSIONS

Disease-specific and generic HRQOL instruments are not redundant when applied together, and the disease-specific 'QUALEFFO-41' and generic GHQ-20 measure different aspects of HRQOL.

Psychometric properties evaluation of the quality of life questionnaire of the European Foundation for Osteoporosis in Arabic population

We aimed to validate QUALEFFO-41 in Arabic language and to examine the use of QUALEFFO-41 in clinical practice for assessing quality of life in patients with vertebral fractures (VF). A total of 201 women were included in the study: 106 (53%) cases with at least one vertebral fracture which had been defined morphometrically and 95 (47%) women with OP or osteopenia and no fractures as a control group. The QUALEFFO was translated into Arabic and applied to case-control pairs with prevalent osteoporotic vertebral fractures to evaluate its reliability, validity, and discriminatory ability. It was also used to evaluate the quality of life (QOL) of case-control with prevalent morphometric fractures. The QOL of all subjects was concurrently assessed using SF-36 for comparison. QUALEFFO-41 had good reliability with adequate convergent and discriminatory validity. There were good correlations between QUALEFFO-41 and SF-36. Subjects with clinical osteoporotic vertebral fractures showed significant impairment of HRQoL on the QUALEFFO compared with controls. Similar results were also observed using the SF-36. ROC curve analysis revealed that QUALEFFO-41 had significant ability to discriminate between morphometric fracture subjects versus and controls. The QUALEFFO discriminates for pain (P = 0.002), physical function (P < 0.0001), social function (P = 0.04), general health (P = 0.001), and mental function (P = 0.01), whereas the SF-36 discriminates exclusively for physical function (P = 0.01) and social function (P = 0.02). The Moroccan Arabic version of the QUALEFFO is a reliable and valid instrument that can be administered to Arabic patients suffering from vertebral fracture osteoporosis to evaluate their quality of life. Its measurement properties were comparable with versions in other languages. In addition, the quality of life measured by QUALEFFO is decreased in patients with vertebral fracture due to OP.

Validation of the Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-31) in Chinese

QUALEFFO-31 is a recently developed disease-specific instrument derived from QUALEFFO-41 and intended to have improved efficacy and response rates. We aimed to validate QUALEFFO-31 in Chinese and examine the use of QUALEFFO-31 in clinical practice. This questionnaire was translated into Chinese and applied to 118 case-control pairs aged between 50 and 85 years with prevalent osteoporotic vertebral fractures to evaluate its validity, repeatability, and discriminatory ability. It was also used to evaluate the quality of life (QOL) of 69 case-control trios with prevalent clinical and morphometric fractures. The QOL of all subjects was concurrently assessed using SF-36 for comparison. QUALEFFO-31 had good internal consistency with adequate convergent and discriminatory validity. The median test-retest repeatability ranged from 0.65-0.85. In general, there were good correlations between QUALEFFO-31 and SF-36. ROC curve analysis revealed that QUALEFFO-31 had significant ability to discriminate between clinical fracture subjects versus morphometric fracture subjects and controls. QUALEFFO-31 also demonstrated higher discriminatory capacity for pain. Subjects with clinical vertebral fractures (CVFs) had a significant reduction in QOL compared with other subjects. The QUALEFFO-31 is a useful tool for assessing QOL in Chinese. It was well accepted and significantly predictive of subjects with CVFs.