Development and psychometric evaluation of item banks for memory and attention - supplements to the EORTC CAT Core instrument.

BACKGROUND: Cancer patients may experience a decrease in cognitive functioning before, during and after cancer treatment. So far, the Quality of Life Group of the European Organisation for Research and Treatment of Cancer (EORTC QLG) developed an item bank to assess self-reported memory and attention within a single, cognitive functioning scale (CF) using computerized adaptive testing (EORTC CAT Core CF item bank). However, the distinction between different cognitive functions might be important to assess the patients' functional status appropriately and to determine treatment impact. To allow for such assessment, the aim of this study was to develop and psychometrically evaluate separate item banks for memory and attention based on the EORTC CAT Core CF item bank. METHODS: In a multistep process including an expert-based content analysis, we assigned 44 items from the EORTC CAT Core CF item bank to the memory or attention domain. Then, we conducted psychometric analyses based on a sample used within the development of the EORTC CAT Core CF item bank. The sample consisted of 1030 cancer patients from Denmark, France, Poland, and the United Kingdom. We evaluated measurement properties of the newly developed item banks using confirmatory factor analysis (CFA) and item response theory model calibration. RESULTS: Item assignment resulted in 31 memory and 13 attention items. Conducted CFAs suggested good fit to a 1-factor model for each domain and no violations of monotonicity or indications of differential item functioning. Evaluation of CATs for both memory and attention confirmed well-functioning item banks with increased power/reduced sample size requirements (for CATs ≥ 4 items and up to 40% reduction in sample size requirements in comparison to non-CAT format). CONCLUSION: Two well-functioning and psychometrically robust item banks for memory and attention were formed from the existing EORTC CAT Core CF item bank. These findings could support further research on self-reported cognitive functioning in cancer patients in clinical trials as well as for real-word-evidence. A more precise assessment of attention and memory deficits in cancer patients will strengthen the evidence on the effects of cancer treatment for different cancer entities, and therefore contribute to shared and informed clinical decision-making.

Patient-reported outcome measures for physical function in cancer patients: content comparison of the EORTC CAT Core, EORTC QLQ-C30, SF-36, FACT-G, and PROMIS measures using the International Classification of Functioning, Disability and Health.

BACKGROUND: Patient-reported physical function (PF) is a key endpoint in cancer clinical trials. Using complex statistical methods, common metrics have been developed to compare scores from different patient-reported outcome (PRO) measures, but such methods do not account for possible differences in questionnaire content. Therefore, the aim of our study was a content comparison of frequently used PRO measures for PF in cancer patients. METHODS: Relying on the framework of the International Classification of Functioning, Disability and Health (ICF) we categorized the item content of the physical domains of the following measures: EORTC CAT Core, EORTC QLQ-C30, SF-36, PROMIS Cancer Item Bank for Physical Function, PROMIS Short Form for Physical Function 20a, and the FACT-G. Item content was linked to ICF categories by two independent reviewers. RESULTS: The 118 items investigated were assigned to 3 components ('d - Activities and Participation', 'b - Body Functions', and 'e - Environmental Factors') and 11 first-level ICF categories. All PF items of the EORTC measures but one were assigned to the first-level ICF categories 'd4 - Mobility' and 'd5 - Self-care', all within the component 'd - Activities and Participation'. The SF-36 additionally included item content related to 'd9 - Community, social and civic life' and the PROMIS Short Form for Physical Function 20a also included content related to 'd6 - domestic life'. The PROMIS Cancer Item Bank (v1.1) covered, in addition, two first-level categories within the component 'b - Body Functions'. The FACT-G Physical Well-being scale was found to be the most diverse scale with item content partly not covered by the ICF framework. DISCUSSION: Our results provide information about conceptual differences between common PRO measures for the assessment of PF in cancer patients. Our results complement quantitative information on psychometric characteristics of these measures and provide a better understanding of the possibilities of establishing common metrics.

Minimally important differences for interpreting the EORTC QLQ-C30 in patients with advanced colorectal cancer treated with chemotherapy.

AIM: The European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) assesses the health-related quality of life of patients in cancer trials. There are currently no minimally important difference (MID) guidelines for the EORTC QLQ-C30 for colorectal cancer (CRC). This study aims to estimate MIDs for the EORTC QLQ-C30 scales in patients with advanced CRC treated with chemotherapy and enrolled in clinical trials. METHOD: The data were obtained from three published EORTC trials that treated CRC patients using chemotherapy. Potential anchors were selected from clinical variables based on their correlation with EORTC QLQ-C30 scales. Anchor-based MIDs for within-group change and between-group change were estimated via the mean change method and linear regression, respectively, and summarized using weighted correlation. Distribution-based MIDs were also examined. RESULTS: Anchor-based MIDs were determined for deterioration in 8 of the 14 EORTC QLQ-C30 scales and in 9 scales for improvement, and varied by scale, direction of change and anchor. MIDs for improvement (deterioration) ranged from 6 to 18 (-11 to -5) points for within-group change and 5 to 15 (-10 to -4) for between-group change. Summarized MIDs (in absolute values) per scale mostly ranged from 5 to 10 points. CONCLUSIONS: These findings have clinical relevance for the interpretation of treatment efficacy and the design of clinical trials by informing sample size requirements.

Establishing the European Norm for the health-related quality of life domains of the computer-adaptive test EORTC CAT Core.

OBJECTIVE: The computer-adaptive test (CAT) of the European Organisation for Research and Treatment of Cancer (EORTC), the EORTC CAT Core, assesses the same 15 domains as the EORTC QLQ-C30 health-related quality of life questionnaire but with increased precision, efficiency, measurement range and flexibility. CAT parameters for estimating scores have been established based on clinical data from cancer patients. This study aimed at establishing the European Norm for each CAT domain based on general population data. METHODS: We collected representative general population data across 11 European Union (EU) countries, Russia, Turkey, Canada and the United States (n ≥ 1000/country; stratified by sex and age). We selected item subsets from each CAT domain for data collection (totalling 86 items). Differential item functioning (DIF) analyses were conducted to investigate cross-cultural measurement invariance. For each domain, means and standard deviations from the EU countries (weighted by country population, sex and age) were used to establish a T-metric with a European general population mean = 50 (standard deviation = 10). RESULTS: A total of 15,386 respondents completed the online survey (n = 11,343 from EU countries). EORTC CAT Core norm scores for all 15 countries were calculated. DIF had negligible impact on scoring. Domain-specific T-scores differed significantly across countries with small to medium effect sizes. CONCLUSION: This study establishes the official European Norm for the EORTC CAT Core. The European CAT Norm can be used globally and allows for meaningful interpretation of scores. Furthermore, CAT scores can be compared with sex- and age-adjusted norm scores at a national level within each of the 15 countries.

General population normative data for the EORTC QLQ-C30 health-related quality of life questionnaire based on 15,386 persons across 13 European countries, Canada and the Unites States.

OBJECTIVE: The European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 health-related quality of life questionnaire is one of the most widely used cancer-specific health-related quality of life questionnaires worldwide. General population norm data can facilitate the interpretation of QLQ-C30 data obtained from cancer patients. This study aimed at systematically collecting norm data from the general population to develop European QLQ-C30 norm scores and to generate comparable norm data for individual countries in Europe and North America. METHODS: We collected QLQ-C30 data from the general population across 11 European Union (EU) countries, Russia, Turkey, Canada and United States (n ≥ 1000/country). Representative samples were stratified by sex and age groups (18-39, 40-49, 50-59, 60-69 and ≥ 70 years). After applying weights based on the United Nations population distribution statistics, we calculated QLQ-C30 domain scores to generate a 'European QLQ-C30 Norm' based on the EU countries. Further, we calculated QLQ-C30 norm scores for all 15 individual countries. RESULTS: A total of 15,386 respondents completed the online survey. For the EU sample, most QLQ-C30 domains showed differences by sex/age, with men scoring somewhat better health than women, while age effects varied across domains. Substantially larger differences were seen in inter-country comparisons, with Austrian and Dutch respondents reporting consistently better health compared with British and Polish respondents. CONCLUSIONS: This study is the first to systematically collect EORTC QLQ-C30 general population norm data across Europe and North America applying a consistent data collection method across 15 countries. These new norm data facilitate valid intra-country as well as inter-country comparisons and QLQ-C30 score interpretation.

Validation of the Danish version of the disease specific instrument EORTC QLQ-CR38 to assess health-related quality of life in patients with colorectal cancer.

BACKGROUND: The European Organisation for Research and Treatment of Cancer (EORTC) quality of life colorectal questionnaire module (QLQ-CR38) was developed in 1999, and an update, the QLQ CR29 was published recently. To date the Danish version of the questionnaire has not been validated. The aim of this study was to examine the psychometric properties of the Danish version of EORTC QLQ-CR38. METHODS: EORTC QLQ-CR38 was administered to 190 patients with colorectal cancer in two Danish hospitals, one month after their operation. A psychometric evaluation of the questionnaire's structure, reliability, convergent, divergent and known-groups validity was performed. RESULTS: Data from 164 (86.3%) patients were available for analysis. The Danish version of EORTC QLQ-CR38 showed satisfactory psychometric properties for the scales: body image, sexual functioning, male sexual problems and defecations problems. Suboptimal psychometric performances were found for the scales: micturition problems, symptoms of the gastrointestinal tract and weight loss. Evaluation of the psychometric properties of the scale chemotherapy side effects was limited by the low number of patients receiving chemotherapy. It was not possible to assess the psychometric properties of the scale female sexual problems and the single item sexual enjoyment due to a high number of missing values. The homogeneity of the study population made the evaluation of known-group validity difficult. CONCLUSIONS: The results of this study suggest that the validity of the Danish version of EORTC QLQ-CR38 is acceptable. Furthermore, the results support the appropriateness of the updated version, the EORTC QLQ-CR29.

Symptoms and problems in a nationally representative sample of advanced cancer patients.

Little is known about the need for palliative care among advanced cancer patients who are not in specialist palliative care. The purpose was to identify prevalence and predictors of symptoms and problems in a nationally representative sample of Danish advanced cancer patients. Patients with cancer stage 3 or 4 from 54 hospital departments (n = 1630) received the EORTC QLQ-C30 questionnaire. Mean scores were calculated according to the scoring manual and in addition a 'symptom/problem' and a 'severe symptom/problem' was defined and calculated. Multiple logistic regression was used to identify predictors. In total, 977 (60%) patients participated. The most frequent symptoms/problems were fatigue (57%; severe 22%) followed by reduced role function, insomnia and pain. Age, cancer stage, primary tumour, type of department, marital status and whether the patient had recently been hospitalized or not were associated with several symptoms and problems. This is probably the first nationally representative study of its kind. It shows that advanced cancer patients in Denmark have symptoms and problems that deserve attention and that some patient groups are especially at risk.

Chronic pain and other sequelae in long-term breast cancer survivors: nationwide survey in Denmark.

OBJECTIVES: To investigate self-reported chronic pain and other sequelae in a nationally representative sample of long-term breast cancer survivors (BCS). DESIGN: Age-stratified random sample of 2,000 female BCS 5 years after primary surgery without recurrence drawn from the Danish Breast Cancer Cooperative Group register, which is representative regarding long-term BCS in Denmark. ASSESSMENT: Self-administered questionnaire including questions on sociodemography, chronic pain (6 months), health-related quality of life (HRQOL) and other sequelae related to breast cancer. Associations with treatment were investigated. Report of chronic pain was compared to normative data. RESULTS: The response rate was 79%. Chronic pain prevalence of 42% was significantly higher in BCS compared to general population women (SRR: 1.32; 95% CI: 1.23-1.42). Sequelae related to breast cancer were paraesthesia 47%, chronic pain 29%, arm/shoulder swelling 25%, phantom sensations 19%, and allodynia 15%. Chronic pain related to breast cancer was significantly associated with poorer HRQOL and higher medicine consumption, and, in multiple logistic regression analysis, with age (<70 years), short education, being single (divorced, widowed, separated), radiotherapy, and time since operation <10 years. Radiotherapy and younger age were significantly associated with most sequelae. CONCLUSION: Chronic pain was more prevalent in BCS compared to the general population. Significant predictors for sequelae related to breast cancer were radiotherapy and younger age. Future research should therefore prioritize sequelae prevention.

Health care utilisation and characteristics of long-term breast cancer survivors: nationwide survey in Denmark.

AIM: To investigate long-term female breast cancer survivors' (BCS') health care utilisation, health, and employment. METHODS: An age-stratified random sample of 2000 female breast cancer survivors (BCS) 5-15 years after primary surgery without recurrence was drawn from the Danish Breast Cancer Cooperative Group register. A self-administered questionnaire assessed sociodemography, health care utilisation, employment, and health-related quality of life (HRQOL). Associations with breast cancer treatment were investigated. RESULTS: Response rate was 79%. Significantly more BCS than the general women population reported health care utilisation (61% versus. 56%; age-standardised risk ratio (SRR): 1.10; 95% confidence interval (CI) 1.05-1.15), but significantly fewer BCS were disability pensioners (15% versus 19%; SRR: 0.77; 95% CI 0.64-0.93). 'Daily activities limited due to sequelae' were reported by 20%, and 'stopped working/changed job due to sequelae' by 11% of BCS. In multiple logistic regression analysis, radiotherapy (odds ratio (OR) 2.54; 95% CI 1.34-4.80) and endocrine therapy (OR 2.48; 95% CI 1.13-5.45, postmenopausal women only) were significantly related to 'stopped working/changed job due to sequelae'. Time since surgery 5-10 years (versus >10 years) was significantly associated with 'daily activities limited due to sequelae' (OR 2.02; CI 1.43-2.84), which, in turn, was significantly related to poorer HRQOL (all p<0.05). Chemotherapy, receptor status, and protocol allocation did not show significant associations in any analyses. CONCLUSION: Significantly more BCS reported health care utilisation. Radiotherapy, shorter time since surgery, and endocrine therapy predicted daily activity and work limitations due to sequelae.

The use of differential item functioning analyses to identify cultural differences in responses to the EORTC QLQ-C30.

INTRODUCTION: The European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 is a widely used health-related quality of life instrument. The main aim of this study is to investigate whether there are international differences in response to the questionnaire that can be explained by cultural factors. METHODS: Analyses involved a database of 106 separate studies including data from over 28,000 respondents. Differential item functioning (DIF) analyses using logistic regression were conducted for each item of the EORTC QLQ-C30 with respect to cultural/geographic group. Results were qualitatively compared with previously reported DIF analyses by translation to explore whether the source of the DIF was more likely to be linguistic or cultural in nature. RESULTS: Although most response patterns were similar, there were a number of international differences in how the questionnaire was answered. The largest variations were found in the results for Eastern Europe and East Asia. Results for the UK, the US and Australia tended to be similar. Many of the European results followed patterns that were more clearly explained when grouped by translation than when grouped by geographical region. DISCUSSION: Our results suggest that, in general, the EORTC QLQ-C30 is suitable for use in a wide variety of countries and settings. Some response variations that have the potential to affect the results of international studies were identified, but it was not always clear whether the source of the variation was primarily linguistic or cultural.

Comparing translations of the EORTC QLQ-C30 using differential item functioning analyses.

The European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 is one of the most widely used quality of life instruments for cancer patients. The aim of this study was to assess whether there were linguistic differences in the way an international sample answered the EORTC QLQ-C30 questionnaire. Thirteen translations of the EORTC QLQ-C30, representing 22 countries, were investigated using a database of 27,891 respondents, incorporating 103 separate studies. Differential item functioning (DIF) analyses were conducted using logistic regression to identify items which, after controlling for subscale, were answered differently by language of administration. Both uniform and non-uniform DIF were assessed. Although most languages showed similar results to English, at least one instance of statistically significant DIF was identified for each translation, and a few of these differences were large. In some cases, the patterns were supported by the results of qualitative interviews with bilingual people. Although, overall, there appeared to be good linguistic equivalence for most of the EORTC QLQ-C30 items, several scales showed strongly discrepant results for some translations. Some of these effects are large enough to impact on the results of clinical trials. Based on our experience in this study, we suggest that validation of translations of health-related quality of life instruments should include exploration of DIF.

Health-related quality of life one month after thrombolysis or primary PCI in patients with ST-elevation infarction. A DANAMI-2 sub-study.

OBJECTIVES: To evaluate the health-related quality of life (HRQoL) following Primary percutaneous coronary intervention (PCI) or thrombolytic treatment for ST-elevation myocardial infarction (STEMI). DESIGN: A questionnaire based study on patients randomised in the DANAMI-2 study to Primary PCI or thrombolysis for STEMI. A total of 1 351 patients (93.2% response rate) randomised in the DANAMI-2 study completed the HRQoL questionnaire one month after the infarction. RESULTS: With respect to the primary end-points (SF-36 physical component score, angina pectoris, and dyspnoea), patients randomised to primary PCI scored better on the SF-36 physical component score (PCS) (p=0.007), and reported significantly less angina pectoris (p=0.010) and dyspnoea (p=0.010). Higher scores among PCI patients were also found on the SF-36 scales physical functioning (p=0.015), role-physical (p=0.017), and general health (p=0.009). CONCLUSION: The results in this study support the hypothesis that primary PCI is superior to thrombolysis in treating STEMI, not only in clinical outcome, but also in quality of life outcome.

Quality of life in the Danish general population--normative data and validity of WHOQOL-BREF using Rasch and item response theory models.

BACKGROUND: The main objective of this study was to investigate the construct validity of the WHOQOL-BREF by use of Rasch and Item Response Theory models and to examine the stability of the model across high/low scoring individuals, gender, education, and depressive illness. Furthermore, the objective of the study was to estimate the reference data for the quality of life questionnaire WHOQOL-BREF in the general Danish population and in subgroups defined by age, gender, and education. METHODS: Mail-out-mail-back questionnaires were sent to a randomly selected sample of the Danish general population. The response rate was 68.5%, and the sample reported here contained 1101 respondents: 578 women and 519 men (four respondents did not indicate their genders). RESULTS: Each of the four domains of the WHOQOL-BREF scale fitted a two-parameter IRT model, but did not fit the Rasch model. Due to multidimensionality, the total score of 26 items fitted neither model. Regression analysis was carried out, showing a level of explained variance of between 10 and 14%. The mean scores of the WHOQOL-BREF are reported as normative data for the general Danish population. CONCLUSION: The profile of the four WHOQOL-BREF domains is a more adequate expression of quality of life than the total score of all 26 items. Although none of the subscales are statistically sufficient measures of their domains, the profile scores seem to be adequate approximations to the optimal score.

Use of item response theory to develop a shortened version of the EORTC QLQ-C30 emotional functioning scale.

BACKGROUND: As part of a larger study whose objective is to develop an abbreviated version of the EORTC QLQ-C30 suitable for research in palliative care, analyses were conducted to determine the feasibility of generating a shorter version of the 4-item emotional functioning (EF) scale that could be scored in the original metric. METHODS: We used data from 24 European cancer studies conducted in 10 different languages (n = 8242). Item selection was based on analyses by item response theory (IRT). Based on the IRT results, a simple scoring algorithm was developed to predict the original 4-item EF sum scale score from a reduced number of items. RESULTS: Both a 3-item and a 2-item version (item 21 'Did you feel tense?' and item 24 'Did you feel depressed?') predicted the total score with excellent agreement and very little bias. In group comparisons, the 2-item scale led to the same conclusions as those based on the original 4-item scale with little or no loss of measurement efficiency. CONCLUSION: Although these results are promising, confirmatory studies are needed based on independent samples. If such additional studies yield comparable results, incorporation of the 2-item EF scale in an abbreviated version of the QLQ-C30 for use in palliative care research settings would be justified. The analyses reported here demonstrate the usefulness of the IRT-based methodology for shortening questionnaire scales.

Symptomatology of cancer patients in palliative care: content validation of self-assessment questionnaires against medical records.

To elucidate which symptoms or problems to measure when evaluating palliative care, we assessed the content validity of selected patient self-assessment questionnaires used to evaluate palliative care: the European Organization for Research and Treatment of Cancer-Quality of Life-Core 30 (EORTC QLQ-C30), the Edmonton Symptom Assessment System (ESAS), the Palliative Care Outcome Scale (POS), the McGill Quality of Life Questionnaire (MQOL) and the Memorial Symptom Assessment Scale (MSAS). The content of the questionnaires was compared against the symptoms and problems noted in the medical records of 171 consecutive cancer patients on their first admission to a department of palliative medicine. From the records, 63 different symptoms were listed. Two questionnaires covered almost all of the prevalent symptoms/problems: the EORTC QLQ-C30 covered 10 and the MSAS 11 of the 12 most frequent problems. Researchers selecting instruments for evaluating palliative care may use the present study and other reviews to examine to what degree a given selection of instruments cover the symptoms/problems targeted by palliative care physicians.

Symptom recognition in advanced cancer. A comparison of nursing records against patient self-rating.

The aim of the study was to investigate the extent to which the symptoms experienced by advanced cancer patients were covered by the nursing records. On the day of the first contact with our palliative care department, a nursing record was taken, and on this or the following day, 56 patients filled in the questionnaires EORTC Quality of Life Questionnaire (EORTC QLQ-C30), Edmonton Symptom Assessment System (ESAS), and Hospital Anxiety and Depression Scale (HADS). In each patient, the symptomatology reported in the patient-completed questionnaires was compared with the symptomatology mentioned by the nurse in the nursing record. The analysis revealed good concordance concerning pain and poor physical functioning, but patients reported other symptoms or problems much more often than their nurses. Reasons for these discrepancies are discussed. It is suggested that the nurse's knowledge of the patient's symptomatology might gain from more systematic screening or from transfer of information from patient self-assessment questionnaires to the nursing records.

Does the medical record cover the symptoms experienced by cancer patients receiving palliative care? A comparison of the record and patient self-rating.

The aim of this study was to investigate the extent to which the symptoms experienced by advanced cancer patients were covered by the medical records. Fifty-eight patients participated in the study. On the day of first encounter with our palliative care department, a medical history was taken, and on this or the following day, the patients completed the EORTC Quality of Life Questionnaire (EORTC QLQ-C30), Edmonton Symptom Assessment System (ESAS), and Hospital Anxiety and Depression Scale (HADS). The symptomatology reported in the patient-completed questionnaires was compared with the symptomatology mentioned by the physician in the medical record. The analysis revealed good concordance concerning pain, but most other symptoms or problems were reported much more often by patients than by their doctors. Reasons for these discrepancies are discussed. It is suggested that the doctor's knowledge of the patient's symptomatology might gain from more systematic screening and transfer of information from patient self-assessment questionnaires to the medical records.

Fatigue in the Danish general population. Influence of sociodemographic factors and disease.

OBJECTIVE: To measure the levels of fatigue in the general population, and to examine how disease and sociodemographic factors influence fatigue. DESIGN: Cross sectional questionnaire study in the Danish general population. SUBJECTS: A random, age stratified sample of 1608 people aged 20-77 with an equal gender distribution (response rate 67%). MAIN OUTCOME MEASURES: Five fatigue scales from the questionnaire Multidimensional Fatigue Inventory: General Fatigue, Physical Fatigue, Reduced Activity, Reduced Motivation and Mental Fatigue. RESULTS: Fatigue scores were skewed towards absence of fatigue. The General Fatigue and Physical Fatigue scales showed the highest fatigue levels while the Reduced Motivation scale showed lowest levels. Gender differences in fatigue scores were small, but the variability among women was higher-that is, more women had high scores. A multiple linear regression analysis showed that respondents of low social status and respondents with a depression had high fatigue scores on all scales, independent of other factors. Chronic somatic disease had an independent direct effect on Mental Fatigue, but for the rest of the scales, the effect of somatic disease depended on age, gender and/or whether the person was living alone. For example, General and Physical Fatigue decreased with age among healthy people, whereas scores on these scales increased with age among those with a somatic disease. CONCLUSIONS: Physical and mental diseases play essential parts for the level of fatigue and as modulators of the associations between sociodemographic factors and fatigue. These interactions should be taken into account in future research on fatigue and sociodemographic factors and when data from clinical studies are compared with normative data from the general population.

Randomised trial of paclitaxel versus doxorubicin as first-line chemotherapy for advanced breast cancer: quality of life evaluation using the EORTC QLQ-C30 and the Rotterdam symptom checklist.

The aim of the study was to compare the quality of life (QL) of patients treated with single-agent paclitaxel versus doxorubicin as first-line chemotherapy for advanced breast cancer. 331 patients with advanced breast cancer were randomised, with 294 eligible for analysis. Patients completed both the EORTC QLQ-C30 questionnaire and the Rotterdam Symptom Checklist (RSCL) with six additional items, at baseline and after the third, fifth and seventh cycles of chemotherapy. A significant difference in progression-free survival in favour of doxorubicin caused a bias in the data with differences in expected completion rates of questionnaires beyond cycle three. Therefore, statistical comparisons were performed only for the first three cycles. Baseline compliance was 64% and 61% for the QLQ-C30 and RSCL questionnaires, respectively. Doxorubicin was associated with significantly more nausea/vomiting (P=0.001), loss of appetite (P=0.010) and a greater burden of disease and treatment (P=0.044), but with less bone pain (P=0.042) and rash (P=0.045) than paclitaxel. Both treatments were associated with improved emotional function and reduction in psychological distress at cycle 3. Longitudinal data suggested that doxorubicin was associated with less pain, specifically bone pain. Doxorubicin was more active but may have had more side-effects during the first three cycles. Long-term QL outcomes could not be assessed.

Methodological issues in the assessment of health-related quality of life in palliative care trials.

Palliative care aims at improving the patient's quality of life. Clinical trials, therefore, often include the patient's subjective evaluation of symptoms and psychosocial problems, so-called health-related quality of life (HRQL), as end-points. Unfortunately, there are frequently methodological weaknesses in the assessment of HRQL. This paper discusses four criteria which can be used in the evaluation of the quality of such studies: I. The authors should document that they have included the relevant HRQL issues in the questionnaire. If a trial misses important issues, its results may be misleading. II. The sample size should be sufficient to detect meaningful differences. Many trials are too small. III. The assessment of HRQL should have the appropriate timing, reflecting the research questions. The symptoms and the benefit resulting from treatments are not constant over time and often have cyclic patterns. The results may therefore be dependent on the timing of the administration of questionnaires to patients and on the time frames specified in the instructions. IV. The data must be reasonably complete. Incomplete data cannot be avoided in palliative care research, but missing data due to administrative failures or unrealistic schedules must be avoided. A pilot study may show whether a study is feasible. Missing data are likely to bias results. Many published palliative care studies are suboptimal with regard to one or more of these four criteria. This should be considered when reading published studies and when new trials are planned.