Impact of self-reported smoking status on health-related quality of life in Singapore

Aim

To evaluate possible differences in health-related quality of life (HRQoL) according to self-reported smoking status in a multiethnic urban Asian population in Singapore.

Subjects and methods

In this community-based cross-sectional survey of a stratified random sample, interviewers obtained socioeconomic, clinical and HRQoL—Short Form-36, Version 2 (SF-36v2), Health Utilities Index Mark 3 (HUI3) and EuroQoL 5-Dimensions (EQ-5D)—data in English, Chinese or Malay. The association between self-reported smoking status and HRQoL at the overall scale and individual attribute levels stratified by gender were evaluated using regression analyses.

Results

Of 3,006 consenting participants with a mean age of 48 (SD: 16.44) years, 49.9 % males, Chinese: Malay: Indian?=?49.9 %: 25.3 %: 24.8 %, 727 (34.4 %) male and 1,386 (65.6 %) female are never smokers, 208 (86.7 %) male and 32 (13.3 %) female are ex-smokers, 104 (78.8 %) male and 28 (21.2 %) female are occasional smokers, while 460 (88.3 %) male and 61 (11.7 %) female are regular smokers. After adjusting for socioeconomic and clinical variables, male ex-smokers reported lower SF-36v2 MCS (regression coefficient: ?1.60, P?=?0.026) and HUI3 utility scores (regression coefficient: ?0.024, P?=?0.040) compared to never smokers. Female regular smokers reported lower HUI3 utility scores as compared to never smokers (regression coefficient: ?0.056, P?=?0.004).

Conclusion

Compared with never smokers, male ex-smokers and female regular smokers reported poorer HRQoL in this multiethnic Asian study.     

Cross-cultural evaluation of the French version of the LEIPAD, a health-related quality of life instrument for use in the elderly living at home

Purpose

To cross-culturally adapt a French version of the LEIPAD, a self-administered questionnaire assessing the health-related quality of life (HRQoL) in adults aged 65 years and over living at home, and to evaluate its psychometric properties.

Methods

After having translated LEIPAD in accordance with guidelines, we studied psychometric properties: reliability and construct validity—factor analysis, relationships between items and scales, internal consistency, concurrent validity with the Medical Outcome Study Short-Form 36 and known-groups validity.

Results

The results obtained in a sample of 195 elderly from the general population showed very good acceptability, with response rates superior to 93 %. Exploratory factor analysis extracted eight factors providing a multidimensionality structure with five misclassifications of items in the seven theoretical scales. Good internal consistency (Cronbach’s alpha ranging from 0.73 and 0.86) and strong test–retest reliability (ICCs higher than 0.80 for six scales and 0.70 for one) were demonstrated. Concurrent validity with the SF-36 showed small to strong expected correlations.

Conclusion

This first evaluation of the French version of LEIPAD’s psychometric properties provides evidence in construct validity and reliability. It would allow HRQoL assessment in clinical and common practice, and investigators would be able to take part in national and international research projects.     

Audit of Diabetes-Dependent Quality of Life (ADDQoL) [Chinese version for Singapore] questionnaire

Background

The Audit of Diabetes-Dependent Quality of Life (ADDQoL) questionnaire is an individualized instrument that measures the impact of diabetes mellitus on quality of life (QOL). With the worldwide increase in the number of Chinese people diagnosed with diabetes, we anticipated that a Chinese-language version of the ADDQoL would be urgently needed.

Objective

To evaluate the reliability and validity of the ADDQoL (Chinese version for Singapore) among Chinese-speaking Singaporeans with type 2 diabetes mellitus (T2DM).

Methods

Chinese versions of the ADDQoL, EuroQoL-Visual Analogue Scale (EQ-VAS), EQ-5D and SF-6D were administered to Chinese-speaking participants with T2DM (aged ≥21 years) at a tertiary acute-care hospital by convenience sampling. The ADDQoL was assessed for the following: internal consistency (Cronbach’s alpha); test-retest reliability (intraclass correlation coefficient [ICC]); factor structure; known-groups validity (insulin requiring vs non-insulin requiring, with vs without diabetes-related complications, overweight/obese vs not overweight/obese); and convergent and divergent validity (with EQ-VAS, EQ-5D and SF-6D). The usefulness of weighting and ‘not applicable’ (NA) options (key features of ADDQoL) were also evaluated.

Results

In 88 participants (58% male, mean [SD] age 56.6 [11.74] years), the mean (SD) ADDQoL average weighted impact (AWI) score was ?2.613 (1.899). Cronbach’s alpha was 0.941 and the ICC was 0.955 (95% CI 0.812, 0.990). In confirmatory factor analysis, the hypothesized one-factor solution was supported. ADDQoL AWI scores correlated strongly with ADDQoL diabetes-dependent global QOL scores (Spearman’s rank correlation coefficient [rs] = 0.5983) and weakly with generic measures (rs = ?0.028 for ADDQoL present global QOL scores, 0.310 for EQ-VAS, 0.164 for EQ-5D and 0.281 for SF-6D). Participants who required insulin, those with diabetes-related complications and those who were overweight/obese reported lower AWI scores, but the differences were not statistically significant. Importance scores of zero were assigned 1–28% of the time and the NA options were selected 3–49% of the time.

Conclusions

The ADDQoL is reliable and probably valid for assessing QOL among Chinese-speaking Singaporeans with T2DM, although known-groups validity warrants further investigation.

     

Single-item electronic administration of the SF-36v2 Health Survey

Purpose

To evaluate the psychometric properties and factor structure of a computerized electronic version of the SF-36v2 Health Survey (SF-36v2) with items administered one-per-page versus the traditional grid format used in the paper-and-pencil version in a sample of physician-diagnosed headache patients.

Methods

Patients (N = 180) completed the SF-36v2 administered as part of a broader study of health outcomes. Scaling assumptions, reliability, factor structure, and the tool’s ability to discriminate between headache pain severity groups were examined.

Results

Frequency distributions showed notable ceiling effects for the role emotional, social functioning, physical functioning, and role physical scales, but negligible (<1.2%) floor effects for any of the scales. Internal consistency reliability coefficients ranged from 0.81 to 0.95 for the eight health domains. Items passed tests of internal consistency and discriminant validity. Principal components’ analyses confirmed the 2-factor structure; the pattern of correlations across scales was consistent with expectations for the physical and mental health components. As expected, patients with severe headache pain had lower mean SF-36v2 scores than those with mild or moderate pain. No significant score differences were observed between mild and moderate pain severity groups.

Conclusions

Single-item electronic administration of the SF-36v2 is reliable and valid for use with headache patients.     

Association of anthropometric measures with SF-36v2 PCS and MCS in a multi-ethnic Asian population

Purpose

Obesity adversely affects health-related quality of life (HRQoL). Most studies have used body mass index (BMI) to measure obesity. Other measures of obesity, such as waist circumference (WC) or waist-to-hip ratio (WHR), may be better predictors of cardiovascular disease and mortality. We, therefore, examined the associations between other anthropometric measures and HRQoL in a multi-ethnic Asian population.

Methods

In this follow-up study from four previous cross-sectional surveys, HRQoL was measured, at follow-up, using the Short-Form 36 version 2 (SF-36v2) questionnaire. Linear regression was used to assess the relationship between anthropometric measures [BMI, WC, waist residuals (WR) (generated by regressing WC on BMI), WHR, waist-to-height ratio (WHtR) and height (Ht)] and HRQoL. We compared the models’ R ², Akaike’s information criteria (AIC), and Schwarz Bayesian information criteria (BIC) from the different models.

Results

Among 4,981 subjects, 47.6 % were men aged 50.6 ± 12.2 and women aged 49.3 ± 11.6 years. All gender-specific anthropometric measures were significantly correlated with BMI, except WR. After adjusting for known determinants of HRQoL, we found significant associations between BMI, WC and WHtR with SF-36v2 Physical Component Summary (PCS) scores in women but not men. In contrast, after adjusting for known determinants of HRQoL, WR and WHR were significantly associated with SF-36v2 Mental Component Summary (MCS) scores in men, but not women. R², AIC and BIC were similar for all anthropometric measures in the final model.

Conclusions

The associations between measures of central obesity and HRQoL differed between men and women. In women, associations were seen with SF-36v2 PCS, but measures of central obesity did not have significant associations with HRQoL after controlling for BMI. In men, an association between WC and SF-36v2 MCS was statistically significant independent of BMI. These gender differences require further investigation.     

Validity of the Thai EQ-5D in an occupational population in Thailand

Purpose

To assess the construct validity of the Thai EuroQoL (EQ-5D) among an occupational population in Thailand.

Methods

Data were derived from a large cohort study among employees of the Electricity Generating Authority of Thailand. In 2008 and 2009, 4,850 participants completed the Thai EQ-5D and Short-Form 36 version 2 (SF-36v2). Thai preferences weights were used to convert EQ-5D health states into EQ-5D index scores. Construct validity of the Thai EQ-5D was examined by specifying and testing hypotheses about the relationships between the EQ-5D, SF-36v2, and participants’ demographic and medical characteristics.

Results

Construct validity of the Thai EQ-5D was supported by expected relationships with SF-36v2 scale and summary scores. For example, SF-36v2 scores on the mental health scale were much lower for participants who reported having problems on the EQ-5D anxiety/depression dimension compared to those reporting no problems (mean norm-based SF-36v2 scores: 52.9 vs. 41.8, p < 0.001). Additionally, reporting a problem in a given EQ-5D dimension was generally associated with lower SF-36v2 summary scores. The EQ-5D index score distinguished between groups of participants in the expected manner, on the basis of sex, age, education and self-reported health, thus providing evidence of known-groups validity.

Conclusion

The study demonstrated good construct validity of the Thai EQ-5D in a large occupational population in Thailand.     

The equivalence of English and Chinese SF-36 versions in bilingual Singapore Chinese

Objective: To assess the equivalence of English and Chinese versions of the SF-36. Methods: Using a crossover design with block randomisation and stratification by age, identical English or Chinese questionnaires containing the English (UK) and Chinese (HK) SF-36 versions were administered 3–16 days apart to 168 free-living, bilingual, ethnic Chinese volunteers in Singapore. Item level equivalence of both versions was assessed by comparing item means and orderings within each scale. Scale level equivalence was assessed by comparing internal consistency (Cronbach's ), results of factor analysis and mean scale scores (using paired t-tests and intra-class correlations). Results: Item and scale level comparisons supported the equivalence of both versions. For both the versions, item means, item ordering and Cronbach's were similar, and factor analysis yielded two factors with similar factor loadings. There was no clinically important difference in mean scale scores for seven of eight scales, and intra-class correlations were excellent/good for five scales (0.69–0.77) and moderate for three scales (0.55–0.57). Conclusion: English (UK) and Chinese (HK) SF-36 versions are equivalent in bilingual Singapore Chinese. Our data suggest that SF-36 scores from English- and Chinese-speaking subjects may be combined in studies using the SF-36, increasing the power and representativeness of such studies.     

Validation of the Chinese version of the Summated Xerostomia Inventory (SXI)

Objectives

The aim of this study was to validate the Chinese version of the Summated Xerostomia Inventory (SXI).

Methods

The English SXI was translated into Chinese, cross-cultural adaptation and pilot tested. The final Chinese version of SXI was tested in a consecutive sample of 212 patients with xerostomia. The reliability of the Chinese version of SXI was determined through internal consistency and test–retest methods. The construct validity of SXI was analysed by content validity, construct validity, and convergent validity.

Results

Cronbach’s alpha value for the SXI score was 0.798, and the test–retest intraclass correlation coefficient value for the SXI score was 0.837. Construct validity was proved by the presence of one-factor structure that accounted for 57.68 % of the variance and fitted well into the model. The correlation between the total score of the SXI and the global oral health question was 0.75, indicating very good correlation (P < 0.01).

Conclusion

This study provided preliminary evidence concerning validity and reliability of the Chinese version of the SXI. The results provide initial evidence that the SXI may be a useful tool for the mainland Chinese xerostomia patients for both clinical and epidemiologic researches.     

Validation of the International Prostate Symptom Score in Chinese males and females with lower urinary tract symptoms

Objectives

To evaluate the translation of the IPSS (Hong Kong Chinese version 1) and to assess the applicability, validity, reliability and sensitivity of the instrument in both males and females with LUTS in Chinese population.

Methods

The translation of the IPSS (Hong Kong Chinese version 1) was reviewed through back translation. Modifications were made, resulting in the development of The IPSS (Hong Kong Chinese version 2). The content validity was assessed by contend validity index. 233 subjects with LUTS were recruited in Hong Kong primary care settings for pilot psychometric testing. The construct validity was assessed by corrected item-total correlation and Pearson’s correlation test against ICIQ-UI SF, IIQ-7 and SF-12 v2. The reliability was assessed by the internal consistency (Cronbach’s Alpha coefficient) and test –retest reliability (Intraclass correlation coefficient). The Sensitivity was determined by performing known group comparisons by independent T-test.

Results

The content validity index for all items could reach 1. Corrected item-total correlation scores were ≥0.4 for four symptom questions (feeling of incomplete bladder emptying, intermittency, weak stream and straining). Overall, the total symptom score moderately correlated with ICIQ-UI SF. The quality of life score moderately correlated with the IIQ-7 but weakly correlated with SF-12 v2. Overall, the reliability of the IPSS (Hong Kong Chinese version 2) was acceptable (Cronbach’s Alpha coefficient?=?0.71, ICC of the symptom questions =0.8, ICC of the quality of life question =0.7). The symptoms questions and quality of life questions of the IPSS (Hong Kong Chinese versions 2) were sensitive in detecting differences between groups.

Conclusions

The IPSS (Hong Kong Chinese version 2) is a valid, reliable and sensitive measure to assess Chinese females and males with lower urinary tract symptoms. The IPSS quality of life question is more sensitive than the generic quality of life measure to differentiate subgroups.     

Psychometric validation of the SF-36<Superscript>®</Superscript> Health Survey in ulcerative colitis: results from a systematic literature review

Purpose

To conduct a systematic literature review of the reliability, construct validity, and responsiveness of the SF-36^® Health Survey (SF-36) in patients with ulcerative colitis (UC).

Methods

We performed a systematic search of electronic medical databases to identify published peer-reviewed studies which reported scores from the eight scales and/or two summary measures of the SF-36 collected from adult patients with UC. Study findings relevant to reliability, construct validity, and responsiveness were reviewed.

Results

Data were extracted and summarized from 43 articles meeting inclusion criteria. Convergent validity was supported by findings that 83% (197/236) of correlations between SF-36 scales and measures of disease symptoms, disease activity, and functioning exceeded the prespecified threshold (r ≥ |0.40|). Known-groups validity was supported by findings of clinically meaningful differences in SF-36 scores between subgroups of patients when classified by disease activity (i.e., active versus inactive), symptom status, and comorbidity status. Responsiveness was supported by findings of clinically meaningful changes in SF-36 scores following treatment in non-comparative trials, and by meaningfully larger improvements in SF-36 scores in treatment arms relative to controls in randomized controlled trials. The sole study of SF-36 reliability found evidence supporting internal consistency (Cronbach’s α ≥ 0.70) for all SF-36 scales and test–retest reliability (intraclass correlation coefficient ≥0.70) for six of eight scales.

Conclusions

Evidence from this systematic literature review indicates that the SF-36 is reliable, valid, and responsive when used with UC patients, supporting the inclusion of the SF-36 as an endpoint in clinical trials for this patient population.

     

Validity and reliability of Persian version of chronic liver disease questionnaire (CLDQ)

Purpose

The aim of this study is to test the psychometric properties of the Persian version of the Chronic Liver Disease Questionnaire (CLDQ) in Iranian candidates for liver transplantation.

Method

One hundred and fifty-five consecutive adult patients awaiting liver transplantation completed the Persian version of CLDQ and the short-form health survey (SF-36). The etiology of cirrhosis, Child Pugh classification and Model for End stage Liver Disease (MELD) scores were taken from medical records.

Results

The scaling success rate for convergent validity was 100% for all domains, and the success rate for item discriminant validity was 95.8% (139/145). The internal consistency (Cronbach ??) for the domains ranged from 0.65 to 0.89. Multitrait?Cmultimethod correlation matrix and factor analysis revealed that the CLDQ and SF-36 measure different constructs of quality of life.

Conclusion

The Persian version of the CLDQ, a disease-specific questionnaire for measuring health-related quality of life, is accepted by liver transplantation candidates with adequate reliability and validity. There is no significant correlation of Child Pugh classification and MELD score with quality of life.     

Feasibility and Psychometric Properties of the Infant Toddler Quality of Life (ITQOL) Questionnaire in a Community-Based Sample of Healthy Infants in China

Objective Evaluate the feasibility and psychometric properties of the Infant Toddler Quality of Life (ITQOL) questionnaire as a measure of health-related quality of life (HRQOL) in a sample of Chinese infants. Methods The linguistically validated Simplified Chinese version of the ITQOL was used in a multicenter, observational study of healthy, term infants (N?=?427), age 6 weeks at enrollment, in China. At Days 1 and 48, parents/guardians completed the ITQOL, the Short Form Health Survey (SF-12v2) and the Infant Gastrointestinal Symptom Questionnaire (IGSQ). ITQOL feasibility, reliability, ceiling/floor effects, concurrent validity and discriminatory validity were evaluated. Results Feasibility of administering the ITQOL was supported by strong response rates (>?97%) with <?1% missing items for all scales except physical abilities. Reliability was acceptable (Cronbach’s alpha?>?0.70) for all scales except Day 1 General Health (0.67). Floor effects were minimal (<?2%), except Day 1 physical abilities (7%). Ceiling effects increased from Days 1 to 48 across all scales. Concurrent validity was demonstrated by correlations between ITQOL infant-focused scales and IGSQ score (r?=??0.20 to ??0.34, p?<?0.001) and between parent-focused scales and SF-12v2 mental health composite (MCS) scores (r?=?0.29–0.46, p?<?0.001). ITQOL scales discriminated between infant subgroups based on illness-related outcomes (sick visits, adverse events) and between parent subgroups based on SF-12v2 MCS scores. Conclusion The Simplified Chinese version of the ITQOL performed well in a community-based sample of Chinese infants, with evidence supporting the instrument’s feasibility, reliability, and validity. These data support the ITQOL as a valuable tool to assess HRQOL in Chinese infants.     

Comparing the Chinese versions of two knee-specific questionnaires (IKDC and KOOS): reliability,validity, and responsiveness

Background

The International Knee Documentation Committee Subjective Knee Form (IKDC) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) are knee-specific questionnaires that have been widely used and translated into numerous languages. However, the differences in the psychometric properties between the Chinese IKDC and KOOS remain unclear. The purpose of this study was to conduct a cross-cultural adaptation of the Chinese IKDC and Chinese KOOS and to compare the psychometric properties of these two measures in patients with various knee injuries from the acute stage up to 12 weeks after receiving treatment.

Methods

The original IKDC and KOOS were translated into Chinese based on the guidelines of cross-cultural adaptation and translation protocols. One hundred and seventy-three patients with various knee injuries were recruited in this study and completed both Chinese IKDC and Chinese KOOS as well as a generic health status questionnaire (Chinese Short Form-36 [SF-36]). The reliability, internal consistency, content validity, convergent and divergent validity and responsiveness of both IKDC and KOOS were assessed with appropriate indices.

Results

The Chinese IKDC showed excellent reliability (ICC?=?0.97) and strong internal consistency (Cronbach alpha?=?0.87). The Chinese KOOS also presented good reliability with ICCs ranging from 0.89 to 0.95 and internal consistency (Cronbach alpha coefficients ranging from 0.76 to 0.97). The content validity of these two questionnaires were excellent, yielding no floor or ceiling effects. Both the Chinese IKDC and KOOS were highly associated with the physical component summary (PCS) score and weakly related to the mental component summary (MCS) score of the SF-36. Responsiveness to change was large (effect size =0.95) for the Chinese IKDC and moderate (effect sizes?=?0.49~0.60) at 12-week after physical therapy.

Conclusion

Both the Chinese IKDC and KOOS demonstrated good psychometric properties. However, the Chinese IKDC was more sensitive to changes over a period of 2, 4, 8, 12 weeks of physical therapy than the Chinese KOOS. The ROC analyses revealed a value of area under the curve (0.83 for the Chinese IKDC and 0.67–0.79 for the subscales of Chinese KOOS). Minimal clinically important difference values were 9.8 for the Chinese IKDC and 0.79, 0.76, 0.76, 0.76, 0.67 for the Symptoms, Pain, Activities of Daily Living, Sport/Recreation, and Quality of Life subscales of Chinese KOOS, respectively. The current study provides information for clinicians and researchers to use these appraisal tools for Chinese-speaking patients with various knee disorders.

     

Comparative validation of the WOMAC osteoarthritis and Lequesne algofunctional indices in Greek patients with hip or knee osteoarthritis

Purpose

To comparatively evaluate the reliability and validity of the Western Ontario and McMaster (WOMAC) and the Lequesne algofunctional indices in Greek patients with hip or knee osteoarthritis (OA).

Methods

The Greek versions of WOMAC LK 3.1 and Lequesne indices were administered to 97 outpatients with OA. Internal consistency reliability was assessed by Cronbach’s alpha and item–scale correlations. Test–retest reliability was examined with intraclass correlations. Patients were also asked to complete the Short Form 36 (SF-36) and a Visual Analog Scale capturing strength of pain, in order to assess construct validity. Additional demographic and clinical data were also recorded to evaluate further associations.

Results

Cronbach’s alpha values of the WOMAC ranged between 0.92 and 0.98 for hip and 0.89–0.97 for knee OA. The respective values for Lequesne were 0.63–0.74 and 0.74–0.80. Item–scale correlations confirmed the superiority of WOMAC with respect to internal consistency reliability. Intraclass correlations were 0.79–0.97 and 0.57–0.98 for hip and 0.86–0.97 and 0.82–0.97 for knee OA, for WOMAC and Lequesne, respectively. The two indices showed high correlations with comparable subscales of SF-36 and the Visual Analog Scale. Significant relationships were identified for age, body mass index, duration of disease, duration of stiffness and radiographic classification.

Conclusions

Our findings, in samples of knee and hip OA patients, indicate that the WOMAC index demonstrates better internal consistency reliability than the Lequesne counterpart, as well as equivalent test–retest reliability and construct validity.     

A community-based study of scaling assumptions and construct validity of the English (UK) and Chinese (HK) SF-36 in Singapore

Scaling assumptions and validity of the English (UK) and Chinese (HK) short form 36 health survey (SF-36) were assessed in a community-based survey of 5503 Chinese, Malays and Indians in Singapore using the international quality of life assessment project approach of item and scale level validation. Missing data for SF-36 items and scales occurred in less than 1.0% of subjects. Item level validation of both versions generally supported assumptions underlying Likert scoring and hypothesised item-order clustering. Item level factor analysis supported the eight-scale structure of the SF-36. In scale level validation, SF-36 scale scores showed wide variability and acceptable internal-consistency reliability (Cronbach's α > 0.70 for six English and seven Chinese scales), conformed to hypothesised patterns and generally varied according to hypotheses in subjects known to differ in quality of life. Scale level factor analysis of both versions yielded very similar patterns of factor correlation, comparable to that found in Japan, but differing from that seen in Western populations. Taken together, these results support the validity of the English (UK) and Chinese (HK) SF-36 versions in the multi-ethnic Asian socio-cultural context of Singapore. This revised version was published online in June 2006 with corrections to the Cover Date.     

Health-related quality of life in young adults in education,employment, or training: development of the Japanese version of Pediatric Quality of Life Inventory (PedsQL) Generic Core Scales Young Adult Version

Purpose

The purpose of the study is to develop a Japanese version of the Pediatric Quality of Life Inventory (PedsQL) Generic Core Scales Young Adult Version (PedsQL-YA-J) and determine the feasibility, reliability, and validity of the scales.

Methods

Translation equivalence and content validity were verified using back-translation and cognitive debriefing tests. A total of 428 young adults recruited from one university, two vocational schools, or five companies completed questionnaires. We determined questionnaire feasibility, internal consistency, and test–retest reliability; checked concurrent validity against the Center for Epidemiologic Studies Depression Scale (CES-D); determined convergent and discriminant validity with the Medical Outcome Study 36-item Short Form Health Survey (SF-36); described known-groups validity with regard to subjective symptoms, illness or injury requiring regular medical visits, and depression; and verified factorial validity.

Results

All scales were internally consistent (Cronbach’s coefficient alpha = 0.77–0.86); test–retest reliability was acceptable (intraclass correlation coefficient = 0.57–0.69); and all scales were concurrently valid with depression (Pearson’s correlation coefficient = 0.43–0.57). The scales convergent and discriminant validity with the SF-36 and CES-D were acceptable. Evaluation of known-groups validity confirmed that the Physical Functioning scale was sensitive for subjective symptoms, the Emotional Functioning scale for depression, and the Work/School Functioning scale for illness or injury requiring regular medical visits. Exploratory factor analysis found a six-factor structure consistent with the assumed structure (cumulative proportion = 57.0 %).

Conclusions

The PedsQL-YA-J is suitable for assessing health-related quality of life in young adults in education, employment, or training, and for clinical trials and epidemiological research.     

Validating the Migraine-Specific Quality of Life Questionnaire v2.1 (MSQ) in Italian inpatients with chronic migraine with a history of medication overuse

Purpose

The purpose of the study is to assess validity, reliability and factor structure of the Italian version of Migraine-Specific Quality of Life Questionnaire v2.1 (MSQ) in patients suffering from chronic migraine (CM) with a history of medication overuse (MO).

Methods

Patients were enroled at hospital admission for withdrawal from MO. Factor analysis was used to confirm the latent structure of the MSQ. Reliability was measured with Cronbach’s alpha coefficient, item-total correlation and inter-item correlation. Construct validity was assessed with Pearson’s coefficient and known-group analysis.

Results

The three-factor structure is basically confirmed. Cronbach’s alpha varied between 0.85 and 0.92; item-total correlations were on average higher than 0.70; average inter-item correlation ranged between 0.63 and 0.65. Correlations were all significant; known-group analysis shows that MSQ score was lower consistently with disease severity.

Conclusions

Our findings confirm the factor structure, reliability and validity of the MSQ and expand results of previous validation studies to the Italian language and to a group of patients with severe CM requiring withdrawal treatment for MO.     

Measuring health-related quality of life in patients with conservatively managed stage 5 chronic kidney disease: limitations of the Medical Outcomes Study Short Form 36: SF-36

Purpose

Chronic kidney disease (CKD) negatively affects health-related quality of life (HRQoL), which is often measured using the Medical Outcomes Study Short Form 36 (SF-36) questionnaire. However, the adequacy of SF-36 in this population has not been reported. We aimed to determine floor and ceiling effects and responsiveness to change of SF-36 in patients with conservatively managed stage 5 CKD.

Methods

SF-36 data were collected prospectively. Floor and ceiling effects were estimated for each SF-36 scale and summary measure based on raw scores. The minimal clinically important difference (MCID) was estimated using a combination of anchor-based and distribution-based methods. Responsiveness to change was assessed by comparing MCID for each scale and summary measure to its smallest detectable change.

Results

SF-36 data were available for 73 of the 74 study participants. Using baseline data, floor and/or ceiling effects were detected for 3 of the 8 SF-36 scales. The anchor-based estimation of MCID based on differences in baseline functional status yielded the most reliable results. For the physical component summary, MCID was estimated at 5.7 points. Whilst the two SF-36 summary measures were responsive to change and free of floor and/or ceiling effects, six of the eight scales were not.

Conclusions

This small study of patients with conservatively managed stage 5 CKD found that only the summary measures of SF-36 and 2 of its 8 scales can be used to assess changes in HRQoL over time. These findings suggest that in this population, alternative HRQoL assessment tools should be considered for future studies.

     

Validation of the Dutch version of the VascuQol questionnaire and the Amsterdam linear disability score in patients with intermittent claudication

Purpose

To assess the reliability and validity of the Dutch version of the vascular quality of life questionnaire (VascuQol) and the AMC Linear Disability Score (ALDS) in patients with stable intermittent claudication (IC).

Methods

During a 5-month period we performed a prospective study in which we included every patient with stable IC, who visited our vascular surgery outpatient clinic and consented to participate. Forty consecutive patients filled in the Dutch VascuQol, the ALDS, and Short Form-36 (SF-36). Twenty patients filled in the same questionnaires after 4?weeks. Internal reliability consistencies were expressed as Cronbach??s ??. Test?Cretest reliability was expressed as intraclass correlation coefficients (ICC). Construct validity was expressed as Spearman rho correlations between SF-36 and relevant domains of Dutch VascuQol and the ALDS.

Results

Internal reliability consistencies were, respectively, good and excellent for the total scores of VascuQol, SF-36, and ALDS (Cronbach??s ??. 0.87, 0.89, and 0.92). Test?Cretest reliability was excellent for the total VascuQol scores [ICC 0.91 (95% CI, 0.78?C0.96)], and for the ALDS [ICC 0.90 (95% CI, 0.76?C0.96)]. Spearman correlations between VascuQol, ALDS, and SF-36 domains varied from r?=?0.34?C0.79.

Conclusion

The Dutch VascuQol is a valid and reliable questionnaire for assessment of Qol in patients with IC. This study confirms the good clinimetric properties of the ALDS for assessing disability in patients with IC.     

The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30): Validation of English version in Singapore

Objective: This study aimed to validate the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30, English version 3.0) in Singaporean cancer patients. Methods: In a cross-sectional study, a heterogeneous sample of cancer patients (n = 57) self-administered a questionnaire containing the QLQ-C30, the Short Form 36 Health Survey (SF-36) and assessing health and sociodemographic status. Construct validity was assessed by testing a priori hypotheses that QLQ-C30 scales would be moderately or strongly correlated with SF-36 scales measuring similar dimensions of health-related quality of life (HRQoL) and that subjects reporting mild symptoms would have better HRQoL scores than those reporting severe symptoms. Internal consistency reliability was assessed using Cronbachs . Results: Strength of Spearmans correlations between the QLQ-C30 and SF-36 scales assessing similar dimensions of HRQoL ranged from 0.35 to 0.67. Subjects with mild symptoms had better scores than those with severe symptoms for all six QLQ-C30 HRQoL scales (p < 0.05 for five scales, Mann–Whitney U tests). Cronbachs ranged from 0.19 for the cognitive functioning scale to 0.91 for the global QoL scale. Conclusion: This study provides preliminary evidence for the validity and reliability of the EORTC QLQ-C30 in English-speaking Singaporean cancer patients.