Do the unlabeled response categories of the Minnesota Living with Heart Failure Questionnaire satisfy the monotonicity assumption of simple-summated scoring?

PURPOSE: Half of the 21-item Minnesota Living with Heart Failure Questionnaire (MLHFQ) response categories are labeled (0 = No, 1 = Very little, 5 = Very much) and half are not (2, 3, and 4). We hypothesized that the unlabeled response options would not be more likely to be chosen at some place along the scale continuum than other response options and, therefore, not satisfy the monotonicity assumption of simple-summated scoring. METHODS: We performed exploratory and confirmatory factor analyses of the MLHFQ items in a sample of 1437 adults in the Better Effectiveness After Transition-Heart Failure study. We evaluated the unlabeled response options using item characteristic curves from item response theory-graded response models for MLHFQ physical and emotional health scales. Then, we examined the impact of collapsing response options on correlations of scale scores with other variables. RESULTS: The sample was 46% female; 71% aged 65 or older; 11% Hispanic, 22% Black, 54% White, and 12% other. The unlabeled response options were rarely chosen. The standard approach to scoring and scores obtained by collapsing adjacent response categories yielded similar associations with other variables, indicating that the existing response options are problematic. CONCLUSIONS: The unlabeled MLHFQ response options do not meet the assumptions of simple-summated scoring. Further assessment of the performance of the unlabeled response options and evaluation of alternative scoring approaches is recommended. Adding labels for response options in future administrations of the MLHFQ should be considered.

The Edmonton Symptom Assessment System: Poor performance as screener for major depression in patients with incurable cancer.

BACKGROUND: Depressive symptoms are prevalent in patients with advanced cancer, sometimes of a severity that fulfil the criteria for a major depressive episode. AIM: The aim of this study was to investigate how the item on depression in the Edmonton Symptom Assessment System with a 0-10 Numerical Rating Scale performed as a screener for major depressive episode. A possible improved performance by adding the Edmonton Symptom Assessment System-Anxiety item was also examined. DESIGN: An international cross-sectional study including patients with incurable cancer was conducted. The Edmonton Symptom Assessment System score was compared against major depressive episode as assessed by the Patient Health Questionnaire-9. Screening performance was examined by sensitivity, specificity and the kappa coefficient. SETTING: Patients with incurable cancer (n = 969), median age 63 years and from eight nationalities provided report. Median Karnofsky Performance Status was 70. Median survival was 229 days (205-255 days). RESULTS: Patient Health Questionnaire-9 major depressive episode was present in 133 of 969 patients (13.7%). Edmonton Symptom Assessment System-Depression screening ability for Patient Health Questionnaire-9 major depressive episode was limited. Area under the receiver operating characteristic curve was 0.71 (0.66-0.76). Valid detection or exclusion of Patient Health Questionnaire-9 major depressive episode could not be concluded at any Edmonton Symptom Assessment System-Depression cut-off; by the cut-off Numerical Rating Scale ⩾ 2, sensitivity was 0.69 and specificity was 0.60. By the cut-off Numerical Rating Scale ⩾ 4, sensitivity was 0.51 and specificity was 0.82. Combined mean ratings by Edmonton Symptom Assessment System-Depression and Edmonton Symptom Assessment System-Anxiety revealed similar limited screening ability. CONCLUSION: The depression and anxiety items of the Edmonton Symptom Assessment System, a frequently used assessment tool in palliative care settings, seem to measure a construct other than major depressive episode as assessed by the Patient Health Questionnaire-9 instrument.

Sensitivity and responsiveness of the patient-reported TED-QOL to rehabilitative surgery in thyroid eye disease.

We tested the sensitivity and responsiveness of the TED-QOL to rehabilitative surgery in thyroid eye disease (TED). The 3-item TED-QOL and 16-item GO-QOL, which assess quality of life (QoL) in TED, were administered to consecutive patients undergoing rehabilitative surgery. The questionnaires were completed pre-and post-operatively to assess sensitivity (ability to discriminate between different surgical groups) and responsiveness (ability to detect within patient changes over time).56 patients underwent 69 procedures for TED (29 orbital decompressions, 15 strabismus operations, 25 eyelid procedures). The differences in scores between the three types of surgery (a measure of sensitivity) were statistically significant at the 5% level pre-operatively and post-operatively for all 3 TED-QOL scales and for both GO-QOL scales, but much more so for the TED-QOL scales in each case. The within-patient changes between the pre- and post-operative scores for the same subjects (a measure of responsiveness) were statistically very highly significant for the TED-QOL overall and appearance scales for each of the surgeries. The pre- and post-operative difference for the TED-QOL functioning scale was highly statistically significant for strabismus surgery but not for decompression or lid surgery. The change between the pre- and post-operative scores for the GO-QOL was significant for the functioning scale with strabismus and lid surgery, and was highly significant for the appearance scale with lid surgery but not for strabismus surgery or decompression. The 3-item TED-QOL is sensitive and responsive to rehabilitative surgery in TED and compares favorably with the lengthier GO-QOL for these parameters.

Should linking replace regression when mapping from profile-based measures to preference-based measures?

BACKGROUND: Profile instruments are frequently used to assess health-related quality of life and other patient-reported outcomes. However, preference-based measures are required for health-economic cost-utility evaluations. RESULTS: Although regression-based approaches are commonly used to map from profile measures to preference measures, we show that this results in biased estimates because of regression to the mean. CONCLUSIONS: Linking (scale-aligning) is proposed as an alternative.

Weight loss, appetite loss and food intake in cancer patients with cancer cachexia: three peas in a pod? - analysis from a multicenter cross sectional study.

BACKGROUND: How to assess cachexia is a barrier both in research and in clinical practice. This study examines the need for assessing both reduced food intake and loss of appetite, to see if these variables can be used interchangeably. A secondary aim is to assess the variance explained by food intake, appetite and weight loss by using tumor-related factors, symptoms and biological markers as explanatory variables. MATERIAL AND METHODS: One thousand and seventy patients with incurable cancer were registered in an observational, cross sectional multicenter study. A total of 885 patients that had complete data on food intake (PG-SGA), appetite (EORTC QLQ-C30) and weight loss were included in the present analysis. The association between reduced food intake and appetite loss was assessed using Spearman's correlation. To find the explained variance of the three symptoms a multivariate analysis was performed. RESULTS: The mean age was 62 years with a mean survival of 247 days and a mean Karnofsky performance status of 72. Thirteen percent of the patients who reported eating less than normal had good appetite and 25% who had unchanged or increased food intake had reduced appetite. Correlation between appetite loss and food intake was 0.50. Explained variance for the regression models was 44% for appetite loss, 27% for food intake and only 13% for weight loss. CONCLUSION: Both appetite loss and food intake should be assessed in cachectic patients since conscious control of eating may sometimes overcome appetite loss. The low explained variance for weight loss is probably caused by the need for more knowledge about metabolism and inflammation, and is consistent with the cancer cachexia definition that claims that in cachexia weight loss is not caused by reduced food intake alone. The questions concerning appetite loss from EORTC-QLQ C30 and food intake from PG-SGA seem practical and informative when dealing with advanced cancer patients.

Don't middle your MIDs: regression to the mean shrinks estimates of minimally important differences.

Minimal important differences (MIDs) for patient-reported outcomes (PROs) are often estimated by selecting a clinical variable to serve as an anchor. Then, differences in the clinical anchor regarded as clinically meaningful or important can be used to estimate the corresponding value of the PRO. Although these MID values are sometimes estimated by regression techniques, we show that this is a biased procedure and should not be used; alternative methods are proposed.

Use of methods for specifying the target difference in randomised controlled trial sample size calculations: Two surveys of trialists' practice.

BACKGROUND: Central to the design of a randomised controlled trial (RCT) is a calculation of the number of participants needed. This is typically achieved by specifying a target difference, which enables the trial to identify a difference of a particular magnitude should one exist. Seven methods have been proposed for formally determining what the target difference should be. However, in practice, it may be driven by convenience or some other informal basis. It is unclear how aware the trialist community is of these formal methods or whether they are used. PURPOSE: To determine current practice regarding the specification of the target difference by surveying trialists. METHODS: Two surveys were conducted: (1) Members of the Society for Clinical Trials (SCT): participants were invited to complete an online survey through the society's email distribution list. Respondents were asked about their awareness, use of, and willingness to recommend methods; (2) Leading UK- and Ireland-based trialists: the survey was sent to UK Clinical Research Collaboration registered Clinical Trials Units, Medical Research Council UK Hubs for Trial Methodology Research, and the Research Design Services of the National Institute for Health Research. This survey also included questions about the most recent trial developed by the respondent's group. RESULTS: Survey 1: Of the 1182 members on the SCT membership email distribution list, 180 responses were received (15%). Awareness of methods ranged from 69 (38%) for health economic methods to 162 (90%) for pilot study. Willingness to recommend among those who had used a particular method ranged from 56% for the opinion-seeking method to 89% for the review of evidence-base method. Survey 2: Of the 61 surveys sent out, 34 (56%) responses were received. Awareness of methods ranged from 33 (97%) for the review of evidence-base and pilot methods to 14 (41%) for the distribution method. The highest level of willingness to recommend among users was for the anchor method (87%). Based upon the most recent trial, the target difference was usually one viewed as important by a stakeholder group, mostly also viewed as a realistic difference given the interventions under evaluation, and sometimes one that led to an achievable sample size. LIMITATIONS: The response rates achieved were relatively low despite the surveys being short, well presented, and having utilised reminders. CONCLUSION: Substantial variations in practice exist with awareness, use, and willingness to recommend methods varying substantially. The findings support the view that sample size calculation is a more complex process than would appear to be the case from trial reports and protocols. Guidance on approaches for sample size estimation may increase both awareness and use of appropriate formal methods.

Thalidomide for previously untreated elderly patients with multiple myeloma: meta-analysis of 1685 individual patient data from 6 randomized clinical trials.

The role of thalidomide for previously untreated elderly patients with multiple myeloma remains unclear. Six randomized controlled trials, launched in or after 2000, compared melphalan and prednisone alone (MP) and with thalidomide (MPT). The effect on overall survival (OS) varied across trials. We carried out a meta-analysis of the 1685 individual patients in these trials. The primary endpoint was OS, and progression-free survival (PFS) and 1-year response rates were secondary endpoints. There was a highly significant benefit to OS from adding thalidomide to MP (hazard ratio = 0.83; 95% confidence interval 0.73-0.94, P = .004), representing increased median OS time of 6.6 months, from 32.7 months (MP) to 39.3 months (MPT). The thalidomide regimen was also associated with superior PFS (hazard ratio = 0.68, 95% confidence interval 0.61-0.76, P < .0001) and better 1-year response rates (partial response or better was 59% on MPT and 37% on MP). Although the trials differed in terms of patient baseline characteristics and thalidomide regimens, there was no evidence that treatment affected OS differently according to levels of the prognostic factors. We conclude that thalidomide added to MP improves OS and PFS in previously untreated elderly patients with multiple myeloma, extending the median survival time by on average 20%.

An evaluation of the response category translations of the EORTC QLQ-C30 questionnaire.

PURPOSE: The aim of this study was to evaluate the translated response categories used in eight translations of the European Organisation for Research and Treatment of Cancer QLQ-C30 questionnaire, which is used in many international clinical trials. Twenty-eight of the 30 items in the questionnaire have the same four response categories: "Not at all", "A little", "Quite a bit" and "Very Much". METHODS: People with knowledge of both English and one of eight European languages were asked to complete an Internet survey. The strength (intensity) of the translated categories was assessed using two separate approaches: one using a verbal response scale and the other a visual analogue scale (VAS). RESULTS: Two hundred and seventy-nine people participated in the survey. Most translations were rated similarly to English. The largest differences were for the German translation of "Quite a bit", which was rated 16.3 points lower than the corresponding English category on a 0-100 VAS. CONCLUSIONS: Most of the translated categories were found to be similar to the English versions and should continue to be used. We recommend that three translated categories should be considered for revision. Similar surveys could be used to assess the categories used in other translated quality of life instruments.

ISOQOL recommends minimum standards for patient-reported outcome measures used in patient-centered outcomes and comparative effectiveness research.

PURPOSE: An essential aspect of patient-centered outcomes research (PCOR) and comparative effectiveness research (CER) is the integration of patient perspectives and experiences with clinical data to evaluate interventions. Thus, PCOR and CER require capturing patient-reported outcome (PRO) data appropriately to inform research, healthcare delivery, and policy. This initiative's goal was to identify minimum standards for the design and selection of a PRO measure for use in PCOR and CER. METHODS: We performed a literature review to find existing guidelines for the selection of PRO measures. We also conducted an online survey of the International Society for Quality of Life Research (ISOQOL) membership to solicit input on PRO standards. A standard was designated as "recommended" when >50 % respondents endorsed it as "required as a minimum standard." RESULTS: The literature review identified 387 articles. Survey response rate was 120 of 506 ISOQOL members. The respondents had an average of 15 years experience in PRO research, and 89 % felt competent or very competent providing feedback. Final recommendations for PRO measure standards included: documentation of the conceptual and measurement model; evidence for reliability, validity (content validity, construct validity, responsiveness); interpretability of scores; quality translation, and acceptable patient and investigator burden. CONCLUSION: The development of these minimum measurement standards is intended to promote the appropriate use of PRO measures to inform PCOR and CER, which in turn can improve the effectiveness and efficiency of healthcare delivery. A next step is to expand these minimum standards to identify best practices for selecting decision-relevant PRO measures.

Comparing higher order models for the EORTC QLQ-C30.

PURPOSE: To investigate the statistical fit of alternative higher order models for summarizing the health-related quality of life profile generated by the EORTC QLQ-C30 questionnaire. METHODS: A 50% random sample was drawn from a dataset of more than 9,000 pre-treatment QLQ-C30 v 3.0 questionnaires completed by cancer patients from 48 countries, differing in primary tumor site and disease stage. Building on a "standard" 14-dimensional QLQ-C30 model, confirmatory factor analysis was used to compare 6 higher order models, including a 1-dimensional (1D) model, a 2D "symptom burden and function" model, two 2D "mental/physical" models, and two models with a "formative" (or "causal") formulation of "symptom burden," and "function." RESULTS: All of the models considered had at least an "adequate" fit to the data: the less restricted the model, the better the fit. The RMSEA fit indices for the various models ranged from 0.042 to 0.061, CFI's 0.90-0.96, and TLI's from 0.96 to 0.98. All chi-square tests were significant. One of the Physical/Mental models had fit indices superior to the other models considered. CONCLUSIONS: The Physical/Mental health model had the best fit of the higher order models considered, and enjoys empirical and theoretical support in comparable instruments and applications.

Responsiveness and minimal important score differences in quality-of-life questionnaires: a comparison of the EORTC QLQ-C30 cancer-specific questionnaire to the generic utility questionnaires EQ-5D and 15D in patients with multiple myeloma.

OBJECTIVES: The aims of this study were to (i) compare the responsiveness of the EORTC QLQ-C30 cancer-specific questionnaire and the generic questionnaires EQ-5D and 15D used for economic evaluation of healthcare interventions and (ii) determine the minimal important differences (MIDs) in these questionnaires. The MID is the smallest change in a quality-of-life score considered important to patients. METHODS: Between 2006 and 2008, 239 patients with multiple myeloma completed the questionnaires at inclusion (T1) and after 3 months (T2). At T2, patients were asked whether they had noticed any change in their quality of life. Responsiveness and MIDs were determined by mean score changes (T2-T1) for patients who, in the interview, stated they had improved, deteriorated, or were unchanged. Responsiveness was also assessed using standardized response means. Wilcoxon tests for pair differences were used to evaluate the statistical significance of the changes. RESULTS: Patients who improved had significantly (P < 0.01) higher scores at T2 in all three questionnaires. Patients who deteriorated reported lower scores at T2; however, for the 15D, the differences in score were not statistically significant. The MIDs for the QLQ-C30, EQ-5D, and 15D were 8, 0.08, and 0.03 in patients who improved and 12, 0.10 and 0.02 in patients who deteriorated, respectively. CONCLUSIONS: All three questionnaires showed an acceptable responsiveness in patients who improved. However, the 15D did not respond optimally in patients who deteriorate and cannot be recommended for use in patients with myeloma.

Development of a computer-administered mobility questionnaire.

PURPOSE: Mobility is an important aspect of physical functioning, but feasible and validated self-report assessment instruments for palliative patients are lacking. This study is a part of the European Palliative Research Network research programme, aiming to develop an internationally endorsed assessment tool for symptoms and functioning in palliative cancer care. The specific aim of the present study is to assess psychometric properties of a mobility item bank, with regards to uni-dimensionality, functional coverage, redundant items and gaps in the scale. METHODS: A cross-sectional study with 604 responses from palliative cancer and 186 from chronic pain patients (mean age 59 ± 14 years, 55% female) was performed. A tablet computer with a touch- sensitive screen was used for data collection. An item pool of 21 mobility items, ranging from sitting without support to running were presented in random order, each scored on a four-category scale rating the difficulty in performing the activity. Psychometric properties were assessed by exploratory factor analysis, internal consistency and item response theory. RESULTS: The mobility scale can be regarded as uni-dimensional and has good internal consistency (Cronbach's alpha = 0.97). Items had a wide functional coverage from low to high functioning. Two items were with poor psychometric properties and two redundant items were removed. There were no obvious gaps in the scale. CONCLUSIONS: The psychometric properties of the scale are good and the next step is to make a pre-programmed version of the scale to be used in a pan-European study.

Overlap of Depressive Symptoms with Health-Related Quality-of-Life Measures.

Because depressive symptoms are a part of health-related quality-of-life (HRQOL) measures, measures of depression will be empirically associated with HRQOL. We discuss examples of published research where authors ignored or did not fully account for overlap between depressive symptom and HRQOL measures. Future researchers need to recognize when their models include conceptually similar variables on the same side or both sides of the equation. This awareness will lead to more accurate conclusions about the prognostic value of depression and other HRQOL measures for health care utilization, mortality, and other outcomes. It will also result in fewer incorrect claims about the effect of depression on HRQOL.

Minimal important differences and response shift in health-related quality of life; a longitudinal study in patients with multiple myeloma.

BACKGROUND: We previously reported that changes of 6-17 percent in the EORTC QLQ-C30 scores are regarded important by patients with multiple myeloma and thus may be considered as Minimal Important Differences (MIDs). However, patients' internal standard of measurement may have changed over time (response shift, RS). In the present work, we evaluated whether myeloma patients experience RS and if this could affect the MID-estimates. METHODS: Between 2006 and 2008, 239 patients with multiple myeloma completed the EORTC QLQ-C30 at baseline (T1) and after three months (T2). At T2, patients were asked if they had noticed any change in the domains pain, fatigue, physical function and global quality of life. They were also asked to give a retrospective judgment of their baseline values on all the four domains. RESULTS: We found clear evidence of RS in myeloma patients. However, there were differences in both magnitude and direction between patients who stated that they improved and those who deteriorated. Deteriorating patients retrospectively reported better health-related quality of life at T1 for the domains pain, fatigue and physical function. In these patients, MIDs adjusted for RS were observed to increase up to 12 percentage points. In contrast, for patients stating that they improved, we only found evidence of statistically significant RS in the domain global quality of life. CONCLUSIONS: MIDs estimated from pre-test/post-test data appeared to be robust against RS in patients reporting improvement over 3-months. This could indicate that RS has a minimal impact on the results in patients who respond to treatment, and that RS may not have an important impact on interpretation of changes reported in clinical trials where an improvement occurs.Although the effect sizes of the RSs were small, RS in deteriorating patients may have an important impact on the interpretation of changes reported in clinical trials.

Differential item functioning (DIF) analyses of health-related quality of life instruments using logistic regression.

BACKGROUND: Differential item functioning (DIF) methods can be used to determine whether different subgroups respond differently to particular items within a health-related quality of life (HRQoL) subscale, after allowing for overall subgroup differences in that scale. This article reviews issues that arise when testing for DIF in HRQoL instruments. We focus on logistic regression methods, which are often used because of their efficiency, simplicity and ease of application. METHODS: A review of logistic regression DIF analyses in HRQoL was undertaken. Methodological articles from other fields and using other DIF methods were also included if considered relevant. RESULTS: There are many competing approaches for the conduct of DIF analyses and many criteria for determining what constitutes significant DIF. DIF in short scales, as commonly found in HRQL instruments, may be more difficult to interpret. Qualitative methods may aid interpretation of such DIF analyses. CONCLUSIONS: A number of methodological choices must be made when applying logistic regression for DIF analyses, and many of these affect the results. We provide recommendations based on reviewing the current evidence. Although the focus is on logistic regression, many of our results should be applicable to DIF analyses in general. There is a need for more empirical and theoretical work in this area.

Investigating the missing data mechanism in quality of life outcomes: a comparison of approaches.

BACKGROUND: Missing data is classified as missing completely at random (MCAR), missing at random (MAR) or missing not at random (MNAR). Knowing the mechanism is useful in identifying the most appropriate analysis. The first aim was to compare different methods for identifying this missing data mechanism to determine if they gave consistent conclusions. Secondly, to investigate whether the reminder-response data can be utilised to help identify the missing data mechanism. METHODS: Five clinical trial datasets that employed a reminder system at follow-up were used. Some quality of life questionnaires were initially missing, but later recovered through reminders. Four methods of determining the missing data mechanism were applied. Two response data scenarios were considered. Firstly, immediate data only; secondly, all observed responses (including reminder-response). RESULTS: In three of five trials the hypothesis tests found evidence against the MCAR assumption. Logistic regression suggested MAR, but was able to use the reminder-collected data to highlight potential MNAR data in two trials. CONCLUSION: The four methods were consistent in determining the missingness mechanism. One hypothesis test was preferred as it is applicable with intermittent missingness. Some inconsistencies between the two data scenarios were found. Ignoring the reminder data could potentially give a distorted view of the missingness mechanism. Utilising reminder data allowed the possibility of MNAR to be considered.

The practical impact of differential item functioning analyses in a health-related quality of life instrument.

INTRODUCTION: Differential item functioning (DIF) analyses are commonly used to evaluate health-related quality of life (HRQoL) instruments. There is, however, a lack of consensus as to how to assess the practical impact of statistically significant DIF results. METHODS: Using our previously published ordinal logistic regression DIF results for the Fatigue scale of a HRQoL instrument as an example, the practical impact on a particular Norwegian clinical trial was investigated. The results were used to determine the difference in mean Fatigue scores assuming that the same trial was conducted in the UK. The results were then compared with published information on what would be considered a clinically important change in scores. RESULTS: The item with the largest DIF effect resulted in differences between the mean English and Norwegian Fatigue scores that, although small, could be considered clinically important. Sensitivity analyses showed that larger differences were found for shorter scales, and when the proportions in each response category were equal. DISCUSSION: Our scenarios suggest that translation differences in an item can result in small, but clinically important, differences at the scale score level. This is more likely to be problematic for observational studies than for clinical trials, where randomised groups are stratified by centre.

An international study of the quality of life of adult patients treated with home parenteral nutrition.

BACKGROUND & AIMS: Home parenteral nutrition-quality of life (HPN-QOL©) is a self-assessment tool for the measurement of QOL in patients on HPN. The aims of this study were: to re-assess the basic psychometric properties of the HPN-QOL© in a multinational sample of adult patients; to provide a description of QOL dimensions by short and long HPN treatment duration; to explore clinical factors potentially associated to QOL scores. METHODS: Patients (n = 699) from 14 countries completed the HPN-QOL©. The questionnaires were analysed to evaluate data completeness, convergent/discriminant validity and internal-consistency reliability. The association of overall QOL and HPN treatment duration as well as other clinical factors were investigated using multivariable linear regression models. RESULTS: The analysis of the multitrait-scaling and internal consistency indicates a good fit with the questionnaire structure for most items. Item discriminant validity correlation was satisfactory and psychometric evaluation of the HPN-QOL© in the different English, French and Italian language patient sub-groups confirmed psychometric equivalence of the three questionnaire versions. The results of the multivariable linear regression showed that QOL scores were significantly associated with HPN duration (better in long-term), underlying disease (better in Crohn's disease and mesenteric ischaemia) and living status (worse in living alone) and, after adjusting for the other factors, with the number of days of HPN infusion per week. CONCLUSIONS: The HPN-QOL©, is a valid tool for measurement of QOL in patients on HPN, to be used in the clinical practice as well as in research.

The relationship between overall quality of life and its subdimensions was influenced by culture: analysis of an international database.

OBJECTIVE: To investigate whether geographic and cultural factors influence the relationship between the global health status quality of life (QL) scale score of the European Organisation for Research and Treatment of Cancer QLQ-C30 questionnaire and seven other subscales representing fatigue, pain, physical, role, emotional, cognitive, and social functioning. STUDY DESIGN AND SETTING: A large international database of QLQ-C30 responses was assembled. A linear regression model was developed predicting the QL scale score and including interactions between geographical/cultural groupings and the seven other scale scores. RESULTS: The pain subscale appeared to have relatively greater influence and fatigue relatively lower influence for those from other European regions compared with respondents from the UK when predicting overall quality of life (QoL). For Scandinavia physical functioning appeared to contribute relatively less. There was evidence of greater emphasis on cognitive functioning for those from South Asia and Latin America compared with the UK, whereas for those from Islamic countries, the role functioning scale appeared to have less influence and physical and social functioning more influence. CONCLUSION: These results provide evidence that different cultural groups may emphasize different aspects of their QoL. This has implications for studies using QoL questionnaires in international comparisons.