Psychometric properties of the Japanese version of the quality of life-Cancer Survivors Instrument

The purpose of this study was to describe the psychometric properties of the Japanese version of the Quality of Life-Cancer Survivors Instrument (QOL-CS-J) developed in the U.S. This study was conducted as a mail survey to survivors of more than 5 years post curative resection for non-small-cell lung cancer (NSCLC) and who had participated in an earlier survey. This survey included the medical and demographic factors, the QOL-CS scores, and the Medical Outcome Study 36-Item Short Form (SF-36). A total of 113 survivors completed the survey. To confirm the reliability, the Cronbach’s α coefficient of each subscale was calculated as an internal consistency (α = 0.65–0.89). To confirm the validity of the trial as conducted, Pearson’s correlation coefficients between the subscales of the QOL-CS and the subscales of the SF-36 were calculated. There were moderate correlations between associated subscales including QOL-CS physical to SF-36 bodily pain (r = 0.45) and vitality (r = 0.52), QOL-CS psychological to SF-36 mental health (r = 0.55), QOL-CS social to SF-36 general health perception (r = 0.31) and mental health (r = 0.47), and QOL-CS total to each subscale of SF-36 (r = 0.25–0.64). Findings demonstrated that the QOL-CS-J adequately measured the QOL in long-term NSCLC survivors.     

Responsiveness of the Adult Attention-Deficit/Hyperactivity Disorder Quality of Life Scale (AAQoL)

Aims This study examined responsiveness of the Adult Attention-Deficit/Hyperactivity Disorder Quality of Life Scale (AAQoL), which was developed to assess health-related quality of life (HRQL) among adults with attention-deficit/hyperactivity disorder (ADHD). Methods Adults with ADHD completed the AAQoL, Conners’ Adult ADHD Rating Scale (CAARS), SF-36, and Endicott Work Productivity Scale (EWPS) at baseline and week 8 of a randomized, placebo-controlled trial of atomoxetine. Clinicians rated symptom severity and improvement (CGI-ADHD-S, CGI-ADHD-I). Responsiveness was examined through effect sizes and association with change in the measures listed previously (Spearman correlations, GLMs). Results Analyses included 328 patients (58.8% male; mean age = 36.9 years). All AAQoL scales reflected significant improvement from baseline to week 8 (P < 0.0001). AAQoL change scores were significantly correlated with change in the CGI-ADHD-S (r = −0.37 to −0.50), EWPS (r = −0.43 to −0.63), and CAARS (r = −0.35 to −0.62) (all P < 0.001). AAQoL change scores significantly discriminated among patients with various levels of symptom improvement. AAQoL effect sizes (−0.67 to −1.11) were larger than effect sizes for the SF-36 (0.15 to −0.39). Conclusions The AAQoL was responsive to change in symptoms of ADHD, and it appears to be a useful outcome measure for treatments of ADHD in adults.     

Is a single-item visual analogue scale as valid,reliable and responsive as multi-item scales in measuring quality of life?

Purpose: To compare the validity, reliability and responsiveness of a single, global quality of life question to multi-item scales. Method: Data were obtained from 83 consecutive patients with oesophageal adenocarcinoma undergoing either transhiatal or transthoracic oesophagectomy. Quality of life was measured at baseline, 5 weeks, 3 and 12 months post-operatively with a single-item Visual Analogue Scale (VAS) ranging from 0 to 100, the multi-item Medical Outcomes Study Short Form-20 (MOS SF-20) and Rotterdam Symptom Check-List (RSCL). Convergent and discriminant validity, test–retest reliability and both distribution-based and anchor-based responsiveness were evaluated. Major findings: At baseline and at 5 weeks, the VAS showed high correlations with the MOS SF-20 health perceptions scale (r = 0.70 and 0.72) and moderate to high correlations with all other subscales of the MOS SF-20 and RSCL (r = 0.29–0.70). The test–retest reliability intra-class correlation for the VAS was 0.87. At 5 weeks post-operatively, the distribution-based responsiveness was moderate for the VAS (standardised response mean: –0.47; effect size: –0.56), high for the physical subscales of the MOS SF-20 and RSCL (–1.08 to –1.51) and low for the psychological subscales (0.11 to –0.25). Five weeks post-operatively, anchor-based responsiveness was highest for the VAS (r = 0.54). Conclusion: The VAS is an instrument with good validity, excellent reliability, moderate distribution-based responsiveness and good anchor-based responsiveness compared to multi-item questionnaires. Its use is recommended in clinical trials to assess global quality of life.     

Development of physical and mental health summary scores from the patient-reported outcomes measurement information system (PROMIS) global items

Background  The use of global health items permits an efficient way of gathering general perceptions of health. These items provide useful summary information about health and are predictive of health care utilization and subsequent mortality. Methods  Analyses of 10 self-reported global health items obtained from an internet survey as part of the Patient-Reported Outcome Measurement Information System (PROMIS) project. We derived summary scores from the global health items. We estimated the associations of the summary scores with the EQ-5D index score and the PROMIS physical function, pain, fatigue, emotional distress, and social health domain scores. Results  Exploratory and confirmatory factor analyses supported a two-factor model. Global physical health (GPH; 4 items on overall physical health, physical function, pain, and fatigue) and global mental health (GMH; 4 items on quality of life, mental health, satisfaction with social activities, and emotional problems) scales were created. The scales had internal consistency reliability coefficients of 0.81 and 0.86, respectively. GPH correlated more strongly with the EQ-5D than did GMH (r = 0.76 vs. 0.59). GPH correlated most strongly with pain impact (r = −0.75) whereas GMH correlated most strongly with depressive symptoms (r = −0.71). Conclusions  Two dimensions representing physical and mental health underlie the global health items in PROMIS. These global health scales can be used to efficiently summarize physical and mental health in patient-reported outcome studies.     

Fatigue in patients with spinal muscular atrophy type II and congenital myopathies: evaluation of the fatigue severity scale

Purpose

The aim of this study was to evaluate whether the fatigue severity scale (FSS) is an appropriate instrument to assess fatigue in patients with spinal muscular atrophy type II (SMA II) and congenital myopathies (CM).

Methods

FSS and visual analog scale (VAS) were administered to 33 SMA II- and 72 CM patients. The psychometric properties of the FSS were evaluated by means of classical test theories for each of the disease groups. If abnormal fatigue was present in the disease group, the construct of fatigue was evaluated by means of focus group interviews.

Results

Fatigue was rare in SMA II patients, but very frequent in patients with CM. The cut-off score designating abnormal fatigue (FSS score ≥ 4) was exceeded by 10 % of the SMA II patients in contrast to 76 % of the CM patients, of whom 52 % suffered from severe fatigue (FSS score ≥ 5). Focus group interviews demonstrated that fatigue had an adverse effect on motor function, level of energy, social relations, and identity, four themes that could be captured by the FSS. The FSS and VAS were strongly correlated in SMA II patients, but only moderately in CM patients. The psychometric properties indicated that the original FSS with nine items measures more than one construct of fatigue, eliminating the first two items improved scale properties.

Conclusion

This study demonstrates that fatigue is characteristic in patients with CM, but not in patients with SMA II, in whom fatigue does not seem to impact daily life. While fatigue in CM and SMA II can be captured by FSS, omitting the first two items of the scale will improve its properties and content validity, along with comprehension of the scale itself.     

Development of a Computer-adaptive Test for Depression (D-CAT)

Depression is one of the most prevalent mental health problems and measuring depressive symptoms becomes increasingly important in science as well as medical practice. Computer Adaptive Tests (CAT) based on the Item Response Theory (IRT) promise to enhance measurement precision and reduce respondent’s burden. Our aim was to develop a CAT application to measure depressive symptoms. Three thousand two hundred seventy psychosomatic patients answered an overall of 11 mental health questionnaires at the University Clinic in Berlin. Three independent reviewers rated 144 items out of these questionnaires as indicative of depressive symptoms. All items underwent six empirical steps to analyze unidimensionality, local independence and item discrimination. Finally 64 items could be used to calculate item parameters applying a Generalized Partial Credit Model (GPCM). CAT scores were estimated using an ‘expected a posteriori’ algorithm (EAP). Two simulation experiments showed that for theta values within the range of 2SD around the mean (98% of the cases), the latent trait can be estimated out of approximately six items with a predefined standard error of ⩽ 0.32 (reliability ρ ⩾ 0.90). The CAT-scores correlated high with scores of all depression items (r = 0.95), with the Beck Depression Inventory (r = 0.79) and with a CES-D 8 item short form (r = 0.76). We conclude that the Depression-CAT measures depressive symptoms with high precision and low respondent burden.     

Impact of Fatigue in Parkinson’s Disease: The Fatigue Impact Scale for Daily Use (D-FIS)

The Fatigue Impact Scale for Daily Use (D-FIS) was used in a cross-sectional study including 142 consecutive Parkinson’s disease (PD) patients. Usual clinical measures for PD, the Montgomery-Asberg Depression Rating Scale and the Parkinson’s Disease Questionnaire-8 items were applied. In addition to the D-FIS, patients with fatigue (67.6%, PWF) completed the Multidimensional Fatigue Inventory (MFI), a visual analogue scale for fatigue (VAS-F) and a Global Perception of Fatigue scale (GPF). Relevant psychometric D-FIS results were: floor effect = 4.2%; ceiling effect = 1.1%; skewness = 0.44; item homogeneity = 0.63; Cronbach’s α = 0.93; item-total correlation = 0.68 (item 1)−0.82 (item 8); standard error of measurement = 2.15; convergent validity with other fatigue measures = 0.54 [GPF]−0.62 [VAS-F] (p<0.001). In a multiple linear regression model, fatigue, depression, and disability independently influenced HRQoL, as measured by the PDQ-8. Patients on amantadine had lower prevalence of fatigue. In PD, D-FIS is a consistent and valid measure for fatigue, a frequent symptom previously found to impair patients’ HRQoL. Fatigue was also linked to depression and disability in this study.     

Subjective Quality of Life According to Work Status Following Interdisciplinary Work Rehabilitation Consequent to Musculoskeletal Disability

Introduction Individualized subjective quality of life (ISQoL) is the appraisal of quality of life according to personal values, desired goal attainment and life priorities. “Gap” is a way to operationalize ISQoL. ISQoL is rarely measured by interdisciplinary work rehabilitation (IWR) programs attended by the musculoskeletal disorder (MSD) population. These programs commonly measure pain intensity, physical capacity, perceived disability, distress and return to work. Objectives The aims of this study were to compare ISQoL according to work status and reference values and to explore the relationships between ISQoL and common IWR measures. Methods Six months after completing an IWR program, 40 working and 31 not-working participants completed questionnaires documenting work status, pain, ISQoL gap, health-related quality of life (SF-36, PCS and MCS), perceived disability and distress. Results No significant difference in global ISQoL gap was found between working and not-working participants. When compared to reference values considerable variability exists but globally, for both groups, ISQoL gap scores were below average. The following clinical variables were related to global ISQoL (P < 0.05): pain (r = −0.42), PCS (r = −0.37), MCS (r = −0.56), perceived disability (r = 0.37) and distress (r = 0.61). High distress, present in both groups, explains 38% of the global ISQoL gap variance and PCS adds 4%. Conclusion Following IWR programs for the chronic MSD population, global ISQoL gap is not related to work status. The use of a client-centered interactive computerized measure of ISQoL reveals that domains related to emotional well-being are likely the most problematic for the persistently disabled MSD population.     

Psychometric evaluation of a Chinese (Taiwanese) version of the SF-36 health survey amongst middle-aged women from a rural community

To test the psychometric properties of the Chinese (Taiwanese) version of the short form 36 health survey (SF-36), 1439 women, aged 40–54 years and living in Kinmen (a Taiwanese island reflecting a predominantly rural community) were recruited to participate in this survey. The rate of unavailable data points for the 36 tested items remained consistently low, and item-discriminate validity was high (95%) for all subscales. Cronbach's α coefficient remained above the 0.70 threshold criterion for all scales except for social functioning and bodily pain. Principal components analysis supported the two major dimensions of health, physical and mental, in the internal structure of the SF-36 scales, although the dimensions did not match the hypothesized association very well. Poorer health profiles were associated with physical and mental conditions. The mental health subscores in the SF-36 test correlated highly with the associated hospital anxiety and depression score (Spearman rank correlation coefficient = −0.62). In conclusion, the reliability and validity tests performed on the data collected support the cross-cultural application of the Chinese (Taiwanese) version of the SF-36 test. This revised version was published online in June 2006 with corrections to the Cover Date.     

Assessing Measurement Properties of Two Single-item General Health Measures

Background: Multi-item health status measures can be lengthy, expensive, and burdensome to collect. Single-item measures may be an alternative. We compared measurement properties of two single-item, general self-rated health (GSRH) questions to assess how well they captured information in a validated, multi-item instrument. Methods: We administered a general health survey (SF-12V) that included “standard” and “comparative” forms of a GSRH. We repeated the survey two weeks later to the same 75 medically stable outpatients to test for GSRH reproducibility, reliability, and validity using SF-12V Physical Functioning and Emotional Health subscales as a reference. Results: At each survey administration, the two GSRH questions demonstrated good alternate forms reliability (first administration: r=0.74, p<0.001; second administration: r=0.74, p<0.001) and good reproducibility (“standard”: ICC 0.69; “comparative”: ICC 0.85). Both GSRH items correlated with physical functioning (“standard”: r=0.66; “comparative”: r=0.56) and emotional health measures (“standard”: r=0.65; “comparative”: r=0.59). Mean subscale measures associated with responses in each GSRH category were significantly different (ANOVA, p<0.001), indicating strong discriminant scale performance. Conclusions: Our single-item, GSRH questions demonstrated good reproducibility, reliability, and strong concurrent and discriminant scale performance with an established health status measure.     

Measuring health-related quality of life in persons with genital herpes

A disease-specific measure was needed for use in an international clinical trial to evaluate an investigational drug for genital herpes. A new measure was developed initially in the UK and translated and adapted for use in France, Italy, Germany, Denmark, Spain and the USA. This paper describes the translation and adaptation of the USA measure. It also describes the assessment of internal consistency, reproducibility, content validity, and construct validity (convergent and discriminant) of the measure. Two outcome measures of the final genital herpes-specific measure were developed: (1) a 21-item symptoms subscale; and (2) a 20-item HRQOL subscale. Each measure was scored and analyzed separately; the psychometric testing discussed in this paper refers to the HRQOL subscale only. The internal consistency of the HRQOL subscale is high (r=0.93), as is the reproducibility measured with a two week interval (r=0.85). Convergent validity is moderate to high. (Fleming Self-Regard subscale,r=0.48; SF-36 Social Functioning dimensionr=0.59; SF-36 Mental Health dimensionr=0.50). The number of herpes outbreaks in the past year was a significant predictor of scores on the HRQOL subscale (0–1 outbreaks, mean=82.1; 2+ outbreaks, mean=72.1,p=0.058) suggesting discriminant validity. The measure is currently in a phase III clinical trial including anti-viral therapy where the question of responsiveness can be addressed.This work was carried out at the University of Washington, School of Public Health and Community Medicine and was funded by Burroughs Wellcome and Wellcome UK     

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     

A patient-based questionnaire to assess outcomes of foot surgery: Validation in the context of surgery for hallux valgus

Background: A patient-based outcome measure with good measurement properties is urgently needed for use in clinical trials of foot surgery. Methods: We evaluated an existing foot pain and disability questionnaire (the Manchester Foot Pain and Disability Questionnaire) for its suitability as an outcome measure in the context of hallux valgus corrective surgery. Interviews with patients led to initial changes, resulting in 20 candidate questionnaire items with five response categories each. These were tested in a prospective study of 100 patients (representing 138 foot operations) undergoing hallux valgus corrective surgery. Analysis of underlying factor structure, dimensionality, internal reliability, construct validity and responsiveness of the questionnaire items in relation to (i) SF-36 general health survey and (ii) American Orthopaedic Foot & Ankle Society (AOFAS) hallux clinical scale resulted in a final 16 item questionnaire (the ‘Manchester-Oxford Foot Questionnaire’ (MOXFQ)), consisting of three domains/scales: ‘Walking/standing’ (seven items), ‘Pain’ (five items) and ‘Social interaction’ (four items) each having good measurement properties. All three domains were unidimensional. Conclusions: The new 16-item MOXFQ has good measurement properties in the context of outcomes assessment of surgery for hallux valgus. Future studies should assess the MOXFQ in the context of surgery for other foot and ankle conditions.     

Demonstration of two types of fatigue in subjects with chronic liver disease using factor analysis

Purpose

The purpose of this investigation was to determine if it was possible to separate fatigue self-reports into two distinct types of fatigue symptom clusters in research subjects with chronic liver disease (CLD). It was hypothesized that when items from the Medical Outcomes Study Short-Form (SF-36v2) are combined with items from the Fatigue Severity Scale (FSS), these distinct factors will emerge.

Methods

Confirmatory and exploratory factor analyses from data collected in a prospective, natural history study of CLD patients were conducted. Items were selected from the SF-36v2 and the FSS for entry into the factor analyses. In order to establish convergent and discriminant validity, derived factor scores were correlated with subscale scores of the Human Activity Profile (HAP), Mental Component Score (MCS) from the SF-36v2, and the Emotional Functioning Subscale of the Chronic Liver Disease Questionnaire (CLDQ-EF).

Results

106 participants with CLD were included (50% female; age: 51?±?10). Two factors were identified. The factors included one that clustered around questions addressing fatigue related to physical activity (peripheral fatigue) and the other to the questions addressing generalized fatigue that did not require physical tasks to produce the fatigue (central fatigue). The standardized factor loadings of all items were greater than 0.6 on their underlying constructs. Moreover, all factor loadings are significant at p?<?0.01. Peripheral fatigue was related to HAP (r?=?0.26, r?=?0.24, p?<?0.01), as was central fatigue (r?=??0.34, r?=??0.33, p?<?0.01). Central fatigue was related to MCS and CLDQ-EF (r?=??0.60; r?=??0.63, p?<?0.01), whereas peripheral fatigue was not (r?=?0.07, p?>?0.40). We then tested the original scales to determine if the newly created factors correlated better with the validity measures. The full FSS did not correlate as well as the newly created central fatigue scale, while the original peripheral fatigue scale (the SF-36v2 physical functioning) was more related to HAP than the newly created scale.

Conclusions

In individuals with CLD, two separate factors pertaining to fatigue were identified. This recognition of the multifaceted nature of fatigue may help increase the specificity of self-reports of fatigue and lead to treatments that can specifically address the underlying factors contributing to fatigue.

     

Measuring quality of life among cervical cancer survivors: preliminary assessment of instrumentation validity in a cross-cultural study

Background With growing interest in cross-cultural and multicultural cancer-related quality of life studies, the need to assess reliability and validity of quality of life measures for linguistically and culturally diverse cancer survivors is pressing. Methods Reliability and validity of the English and Spanish versions of the Functional Assessment of Cancer Therapy (FACT)-G subscales were tested with a sample of English-speaking European American (n = 273) and ethnic minority American (n = 194), and Spanish-speaking Latina (n = 199) cervical cancer survivors in the U.S. Results Reliability coefficients (Cronbach’s alpha) were 0.76 or higher across ethnic/linguistic groups except for the emotional wellbeing subscale among Spanish-speaking Latinas (α = 0.64). Factor analyses demonstrated overall measurement equivalence across groups with some ethnic/linguistic variations: there were greater differences between linguistic groups than between ethnic groups. Additionally, the scale’s factor structure was less satisfactory for Spanish-speaking Latinas. The subscales had good concurrent validity with appropriate subscales of the Short Form (SF)-12 and Rand/SF-36 General Health subscale (Pearson’s r 0.53–0.66), suggesting each subscale was assessing its intended construct. Conclusion The overall psychometric properties of the FACT-G were cross-culturally equivalent. However, more validation studies are needed for non-English speaking populations particularly with emotional wellbeing. In addition, disaggregated analyses on linguistic groups are recommended unless cross-cultural equivalence is established. All participants in this study have provided written informed consent as required by the University of California at Los Angeles Institutional Review Board.     

Validation of the Chinese version of the Schizophrenia Quality of Life Scale Revision 4 (SQLS-R4) in Taiwanese patients with schizophrenia

We tested the reliability, sensitivity, and validity of a Chinese translation of the Schizophrenia Quality of Life Scale Revision 4 (SQLS-R4). One hundred Taiwanese individuals with schizophrenia were recruited. The internal consistency reliability was satisfactory for both the psychosocial and vitality domains (Cronbach’s α = 0.92, 0.84). The test–retest reliability was also high (psychosocial: ICC = 0.84, vitality: ICC = 0.84) for those individuals whose psychological conditions remained stable between the two-week interval. However, the responsiveness coefficient for those with considerable changes in psychological conditions ranged from very small to moderate, suggesting either low responsiveness for the vitality domain or a complex relationship between the change of psychological conditions and quality of life, and the need to estimate responsiveness more conclusively in a future intervention study. The convergent validity was supported by moderate-to-large correlations between domains measuring related constructs of the SQLS-R4 and SF-36 (r = −0.65 to −0.67). Overall, the results of this study provide preliminary evidence for the reliability and validity of the SQLS-R4 used in Taiwanese individuals with schizophrenia. This study provides a common ground for international researchers to understand quality of life in Taiwanese patients with schizophrenia.     

Outcome measurement in functional somatic syndromes: SF-36 summary scores and some scales were not valid

Objective

This study aimed to test the validity of the 36-item Short-Form Health Survey (SF-36) scales and summaries in patients with severe functional somatic syndromes (FSS), such as fibromyalgia and irritable bowel syndrome.

Study Design and Setting

One hundred twenty patients with severe FSS enrolled in a randomized controlled trial filled in the SF-36 questionnaire. We tested for data quality, central scaling assumptions, and agreement with the conceptual model.

Results

Most SF-36 scales were found to be valid; however, three scales (role physical, role emotional, and general health) did not satisfy predefined criteria for construct validity, internal consistency, or targeting to the sample. The correlations between SF-36 scales differed considerably from those reported in the general population. As a consequence, the SF-36 summaries, physical component summary (PCS) and mental component summary (MCS), did not accurately reflect their underlying scales and were negatively correlated (r = −0.46, 95% CI [−0.60 to −0.31]).

Conclusion

Although the SF-36 is a valuable instrument to assess perceived health in patients with severe FSS, there are problems with some of the scales and with the scoring procedure of the summaries. The SF-36 PCS may, therefore, not accurately measure the physical health status of these patients. Alternative summary measures are needed.     

Korean version of the Caregiver Quality of Life Index – Cancer (CQOLC-K)

Objective: The aim of this study was to develop and evaluate the internal consistency and construct validity of a Korean version of the Caregiver Quality of Life Index – Cancer (CQOLC-K). Methods: The CQOLC-K was administered to 270 caregivers, along with the Medical Outcomes Study Short Form-36 (SF-36) and the Beck Depression Inventory (BDI). Results: Internal consistency of the CQOLC-K (0.90) and all inter-scale correlations were significant in the expected direction (p < 0.001). Convergent validity was supported with moderate to strong correlations between the CQOLC-K and the mental component scores of the SF-36 (r = 0.39–0.58), and between the CQOLC-K and the two BDI scores (r = 0.50 and 0.60). Divergent validity was supported by weaker or negligible correlations between the CQOLC-K and the physical component scores of the SF-36 (r = 0.16–0.30). Contrasting groups validity showed that the CQOLC-K was able to distinguish clearly between patients differing in treatment history (p < 0.005), performance status (p < 0.005), care area (p < 0.005), and length of time after diagnosis (p < 0.005). Conclusion: These findings support the internal consistency reliability and construct validity of the Korean version of the CQOLC-K. The instrument can be used to measure quality of life in caregivers of cancer patients in clinical and epidemiological research.     

Development and validation of a specific quality of life module in post-menopausal women with osteoporosis: The QUALIOST™

Established post-menopausal osteoporosis (PMO) has serious consequences on health related quality of life (HRQL), as long-term back and joint pain can severely limit normal activities. The quality of life questionnaire in osteoporosis (QUALIOST^™), a self-administered module consisting of 23 questions which complements the SF-36, was specifically designed to evaluate the repercussions of PMO on patient HRQL. The QUALIOST^™ was developed simultaneously in French and English after discussion with 45 patients. A validation study in France and the UK included 140 women with PMO, with at least one osteoporotic vertebral fracture. Patients completed the SF-36 and QUALIOST^™ twice, 7 days apart. Factorial analysis revealed a physical and emotional component. Three scores were calculated: physical repercussions (10 items), emotional repercussions (13 items) and the global score (23 items). Internal reliability and stability over time were excellent. Concurrent validity with the SF-36 physical and mental fields was satisfactory. A deterioration in clinical state, as measured by pain severity, hospital admission and walking stick use, increased the repercussions on HRQL for all three scores, demonstrating the clinical validity of the questionnaire. The QUALIOST^™, combined with the SF-36, is a valid rating scale for measuring HRQL in clinical trials for established PMO, providing both general and specific data on the effects of PMO on patient HRQL. This revised version was published online in June 2006 with corrections to the Cover Date.     

Rhinitis Symptom Utility Index (RSUI) in Chinese Subjects: A Multiattribute Patient-preference Approach

Background: The Rhinitis Symptom Utility Index (RSUI), originally developed in the United States, consists of a patient-preference weighting scheme and a 10-item questionnaire measuring the severity and frequency of rhinitis related symptoms over a 14-day period. This study aimed to determine whether the Chinese RSUI could adopt the US-based multi-attribute utility function (MAUF) in scoring rhinitis symptoms. Methods: In a Hong Kong study, 116 Chinese adults with allergic rhinitis completed the RSUI questionnaire and 36-item Short-Form Health Survey (SF-36) after they had been seen by two otorhinolaryngologists for disease-severity ratings. Respondents then completed computer-administered direct preference measures, i.e., visual analogue scale (VAS) and standard gamble (SG) assessments. The VAS and SG data were used to estimate a MAUF for the Chinese-based RSUI. Results: The derived MAUF was somewhat different than the one developed for the US RSUI. Test–retest reliability for the Chinese RSUI was satisfactory (ICC = 0.71, p<0.001). Scores differentiated among cases with mild, moderate, and severe symptoms (p<0.001); and between those who did and did not require medications to control symptoms (p = 0.031). Findings were significantly correlated with SF-36 domain scores (r = 0.19 to 0.37; p=0.041 to <0.001). When the US-based scoring function was applied to the Chinese subjects, the resulting mean RSUI score was significantly lower (p<0.001). Comparisons between directly measured VAS and SG scores between the US and Chinese samples, demonstrated significant differences (all p<0.05), with the US subjects consistently rating rhinitis symptoms as worse than Chinese subjects. Conclusions: The Chinese RSUI has good measurement properties that reflect patient preferences from the Chinese. Results suggest that there are differences in preference rating between US and Chinese subjects and that use of the US-based preference function for the RSUI would bias the measurement of rhinitis symptom outcomes in Chinese subjects.