Validity and reliability of the novel thyroid-specific quality of life questionnaire, ThyPRO

BACKGROUND

Appropriate scale validity and internal consistency reliability have recently been documented for the new thyroid-specific quality of life (QoL) patient-reported outcome (PRO) measure for benign thyroid disorders, the ThyPRO. However, before clinical use, clinical validity and test-retest reliability should be evaluated.

AIM

To investigate clinical ('known-groups') validity and test-retest reliability of the Danish version of the ThyPRO.

METHODS

For each of the 13 ThyPRO scales, we defined groups expected to have high versus low scores ('known-groups'). The clinical validity (known-groups validity) was evaluated by whether the ThyPRO scales could detect expected differences in a cross-sectional study of 907 thyroid patients. Test-retest reliability was evaluated by intra-class correlations of two responses to the ThyPRO 2 weeks apart in a subsample of 87 stable patients.

RESULTS

On all 13 ThyPRO scales, we found substantial and significant differences between the groups expected to have high versus low scores. Test-retest reliability was above 0.70 (range 0.77-0.89) for all scales, which is usually considered necessary for comparisons among patient groups, but below 0.90, which is the usual threshold for use in individual patients.

CONCLUSION

We found support for the clinical validity of the new thyroid-specific QoL questionnaire, ThyPRO, and evidence of good test-retest reliability. The questionnaire is now ready for use in clinical studies of patients with thyroid diseases.

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.

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.

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 patients with skeletal metastases of prostate cancer and status prior to start of endocrine therapy: Results from the scandinavian prostate cancer group study 5

OBJECTIVES

Prostate cancer (PC) is a highly lethal neoplastic disease affecting the physical, mental and social well-being of patients, i.e. their quality of life (QOL). Patients suffering from metastatic PC are faced with serious decisions regarding treatment strategies. Therefore, QOL information has become a crucial element of decision making in this group of patients. The first objective of this study was to describe QOL in a group of patients diagnosed with metastatic PC and skeletal metastases. At the time of evaluation the patients had not received any treatment but were evaluated before entering a study of androgen-modulating therapy (the Scandinavian Prostate Cancer Group study 5). The second objective was to identify demographic and disease-related factors affecting QOL.

MATERIAL AND METHODS

A total of 917 patients with metastatic PC were evaluated using a well-described and validated questionnaire [European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire-C30 (EORTC QLQ-C30)]. The characteristics of the PC were noted, and simultaneously patients were evaluated with respect to use of analgesics, pain and performance status using a scoring system. Biochemical tests were performed when patients entered the study. A multivariate regression analysis was performed to analyse the correlations between QOL scores, patient demographics and disease-related data.

RESULTS

The patients reported QOL scores significantly lower than those in the background population. Pain and fatigue were pronounced, whereas dyspnoea, insomnia, loss of appetite, constipation and diarrhoea were less prominent. Patients with high tumour grades, high PSPA scores (the sum of the pain score, the performance status and the use of analgesics) and those using analgesics had significantly lower QOL scores than the other patients.

CONCLUSIONS

Patients with metastatic PC have reduced QOL. Our findings are in line with those of other studies of QOL among patients with this disease as evaluated by means of the EORTC QLQ-C30 questionnaire. Baseline data from studies like this provide important information when treatment modalities for PC are evaluated.

Health related quality of life in a nationally representative sample of haematological patients

OBJECTIVES

Knowledge of health related quality of life of haematological patients is limited. This study aimed at investigating the prevalence and predictors of symptoms and problems in a representative sample of haematological patients in Denmark.

METHODS

A random sample of patients with leukaemia, multiple myeloma and advanced lymphoma (n = 732) received the European Organisation for Research and Treatment of Cancer quality-of-life questionnaire (EORTC QLQ-C30). Mean scores were calculated. In addition, scores were dichotomised using two thresholds: patients reporting at least 'a little' of each EORTC QLQ-C30 symptom/problem were classified as having a 'symptom/problem', and patients reporting at least 'quite a bit' were classified as having a 'severe symptom/problem'. Multiple logistic regression was used to identify predictors.

RESULTS

In total, 470 (64%) patients participated. The most frequent symptoms/problems were fatigue (55%; severe 20%), reduced role function (49%; severe 23%), insomnia (46%; severe 15%), and pain (37%; severe 15%). Older patients and patients in active antineoplastic treatment had more symptoms and problems. There was only little evidence of social inequalities.

CONCLUSION

This is probably the first nationally representative study of symptoms and problems in haematological patients. These patients have symptoms/problems that deserve attention. Health related quality of life is an important issue in haematological malignancies.

Differential item functioning (DIF) in the EORTC QLQ-C30: a comparison of baseline, on-treatment and off-treatment data

INTRODUCTION

Differential item functioning (DIF) analyses can be used to explore translation, cultural, gender or other differences in the performance of quality of life (QoL) instruments. These analyses are commonly performed using "baseline" or pretreatment data. We previously reported DIF analyses to examine the pattern of item responses for translations of the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 QoL instrument, using only data collected prior to cancer treatment. We now compare the consistency of these results with similar analyses of on-treatment and off-treatment assessments and explore whether item relationships differ from those at baseline.

METHODS

Logistic regression DIF analyses were used to examine the translation of each item in each multi-item scale at the three time points, after controlling for the overall scale score and other covariates. The consistency of results at the three time points was explored.

RESULTS

For most EORTC QLQ-C30 subscales, the DIF results were very consistent across the three time points. Results for the Nausea and Vomiting scale varied the most across assessments.

DISCUSSION

The results indicated that DIF analyses were stable across each time point and that the same DIF effects were usually found regardless of the treatment status of the respondent.

A simulation study provided sample size guidance for differential item functioning (DIF) studies using short scales

OBJECTIVE

Differential item functioning (DIF) analyses are increasingly used to evaluate health-related quality of life (HRQoL) instruments, which often include relatively short subscales. Computer simulations were used to explore how various factors including scale length affect analysis of DIF by ordinal logistic regression.

STUDY DESIGN AND SETTING

Simulated data, representative of HRQoL scales with four-category items, were generated. The power and type I error rates of the DIF method were then investigated when, respectively, DIF was deliberately introduced and when no DIF was added. The sample size, scale length, floor effects (FEs) and significance level were varied.

RESULTS

When there was no DIF, type I error rates were close to 5%. Detecting moderate uniform DIF in a two-item scale required a sample size of 300 per group for adequate (>80%) power. For longer scales, a sample size of 200 was adequate. Considerably larger sample sizes were required to detect nonuniform DIF, when there were extreme FEs or when a reduced type I error rate was required.

CONCLUSION

The impact of the number of items in the scale was relatively small. Ordinal logistic regression successfully detects DIF for HRQoL instruments with short scales. Sample size guidelines are provided.

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.

Which domains of thyroid-related quality of life are most relevant? Patients and clinicians provide complementary perspectives

OBJECTIVE

To identify how thyroid diseases impact the patients' lives and to select the most relevant quality of life (QoL) issues for a thyroid-specific questionnaire.

DESIGN

Fifteen thyroid experts and 80 thyroid outpatients (14 with nontoxic goiter, 12 nodular toxic goiter, 21 Graves' disease, 17 thyroid-associated ophthalmopathy, and 16 primary hypothyroidism) were interviewed.

METHODS

The relevance of 138 thyroid disease-related issues was rated during interviews. For each issue, three relevance measures were obtained: a diagnosis-specific patient rating, a diagnosis-specific expert rating, and a combined overall patient/expert rating. The 75 most relevant issues overall and the 15 most relevant issues in each patient category were selected.

RESULTS

Based on the above, 92 issues were selected, covering a broad range of clinical and QoL domains. Across patient groups, broader QoL domains were most relevant, especially fatigue and emotional susceptibility. However, when focusing on individual patient groups, diagnosis-related physical symptoms were very relevant too. Patients rated issues about psychosocial problems and impact on daily life as more relevant, whereas clinicians focused on thyroid-characteristic issues.

CONCLUSIONS

A broad range of QoL issues and physical symptoms are relevant for thyroid patients, particularly fatigue and emotional susceptibility. Patients and clinicians offer complementary perspectives on relevance.

Does the agreement of patient and physician assessments of health related quality of life in palliative care depend on patient characteristics?

OBJECTIVE

Using physician assessments of patients' health related quality of life may improve the feasibility of studies in palliative care. However, poor agreement between patients and physicians has been found. We investigated whether subgroups of patients with good agreement existed.

STUDY DESIGN AND SETTING

Patient and physician assessments of twelve European Organisation for Research and Treatment of Cancer Quality of Life Care Questionnaire 30 domains were obtained once a week for up to 13 weeks. The association between agreement and patient characteristics at the first assessment (n = 115) was investigated using multivariate logistic regression. Significant associations were verified using the follow-up time-points combined (total n = 263).

RESULTS

Significant associations between patient characteristics and agreement were found for most domains. However, few subgroups had good agreement. The evaluations on follow-up data did not confirm the findings of subgroups with good agreement.

CONCLUSION

Based on our findings physician assessments cannot be recommended as a substitute for patient self-assessment for any subgroups of palliative care patients.

Psychological distress and fatigue predicted recurrence and survival in primary breast cancer patients

This study examined whether psychological distress in newly diagnosed breast cancer patients was associated with their survival. We analyzed data from 1,588 breast cancer patients who filled in the EORTC QLQ-C30 questionnaire and the Hospital Anxiety and Depression Scale (HADS) 2 months after their primary operation. The median follow-up time was 12.9 years. Psychological distress (EORTC QLQ-C30 emotional function; HADS anxiety; HADS depression) and EORTC fatigue, physical function, and overall ratings were used to predict recurrence-free and overall survival, controlling for the known clinical and histopathological prognostic factors (biological model) using Cox multivariate regression analysis. Low levels of psychological distress (good EORTC emotional function) and low fatigue independently predicted longer recurrence-free and overall survival, controlling for biological factors. Lack of anxiety (HADS) also predicted longer recurrence-free survival. When added in combination to the biological model, fatigue remained a significant predictor of recurrence-free survival (P = 0.0004; risk ratio 1.32 (1.13-1.54)) and emotional function remained a significant predictor of overall survival (P = 0.0074; risk ratio 0.81 (0.70-0.95)). Low psychological distress and a low level of fatigue may cause a greater cancer resistance or may reflect underlying mental and physical robustness.

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.

Breast cancer patients on adjuvant chemotherapy report a wide range of problems not identified by health-care staff

BACKGROUND

Adjuvant chemotherapy for primary breast cancer is associated with significant side effects. The aims of this study were (1) to compare health-related quality of life (HRQL) in patients undergoing adjuvant chemotherapy to patients not on chemotherapy and (2) to compare these results against a survey investigating health-care professionals' knowledge of HRQL.

METHODS

Patients on adjuvant cyclophosphamide, methotrexate, fluoracil chemotherapy were compared to 'low-risk' patients not on chemotherapy ('control group'). A questionnaire including the EORTC QLQ-C30, the Hospital Anxiety and Depression Scale (HADS), and the DBCG 89 Questionnaire was administered six times during a 2-year period. Forty-six experienced health-care professionals were asked which quality-of-life issues they thought were affected by adjuvant chemotherapy.

RESULTS

After 2 years, 159 of 242 patients on chemotherapy and 148 of 199 patients in the control group were alive and recurrence-free and had completed all questionnaires. Worse HRQL during chemotherapy was seen, as had been previously suggested, for 23 of 30 variables. A number of the health-care professionals had not indicated patients to have these side effects. Several side effects persisted after the chemotherapy.

CONCLUSIONS

This study provides the most comprehensive description of HRQL in adjuvant therapy to date. The discrepancy between patients and doctors/nurses suggests that patients have been insufficiently informed about the impact of chemotherapy on quality of life. The results of this study provide a basis for information that can be given to patients, and indicate that the care offered to patients in chemotherapy should seek to prevent, identify, and alleviate a very broad range of problems.

Health-related quality of life in long-term breast cancer survivors: nationwide survey in Denmark

AIM

To investigate health-related quality of life (HRQOL) in a nationally representative sample of long-term breast cancer survivors (BCS) in Denmark.

PARTICIPANTS AND METHODS

An age-stratified random sample of 2,000 female BCS > or = 5 years after primary surgery without recurrence was drawn from the Danish Breast Cancer Cooperative Group register, which is representative regarding long-term BCS in Denmark, and compared with 3,104 women of the nationally representative Danish Health and Morbidity Survey 2000. The Short Form-36 questionnaire assessed HRQOL and its association with BCS' sociodemography, type of surgery, systemic therapy, radiotherapy, time since operation, receptor status, and low/high risk protocol.

RESULTS

The response rate was 79%. BCS tended to rate HRQOL better than the general female population. BCS reported significantly less "bodily pain" (P < 0.0001), better "general health" (P < 0.0001), but worse "mental health" (P < 0.0001). Age interacted significantly with four other subscales (P < 0.05): Younger BCS reported worse HRQOL than equally aged women of the general population, while older BCS reported better HRQOL. Poor HRQOL was significantly associated with being single (all subscales: P < 0.05), short education (all subscales: P < 0.05, except "social function"), and high body mass index ("physical function", "role physical": P < 0.05). Breast cancer (low/high risk, receptor status) and treatment did not affect HRQOL.

CONCLUSION

HRQOL was similar between BCS and women of the general population. Potential long-term effects of breast cancer (low/high risk, receptor status) and treatment did not seem to impact HRQOL. However, predictors for worse HRQOL in BCS were being single, and having a short education.

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.

Multidimensional measurement of fatigue in advanced cancer patients in palliative care: an application of the multidimensional fatigue inventory

To investigate the level, dimensionality, and correlates associated with fatigue in patients receiving specialist palliative care, 278 advanced cancer patients referred to a department of palliative medicine during a 2-year period were asked to complete the Multidimensional Fatigue Inventory (MFI-20), a self-assessment questionnaire measuring five dimensions of fatigue, and the Hospital Anxiety and Depression Scale. Of 267 eligible patients, 130 (49%) participated. Mean fatigue scores (0-100 scale) were very high, especially for general fatigue (81), physical fatigue (87), and reduced activity (85). Only some of the MFI-20 subscales were significantly correlated. Fatigue was not correlated with sociodemographic factors. Depressed patients had higher scores on all five subscales except physical fatigue. Anxious patients had higher levels on the mental fatigue subscale only. The variation in fatigue explained by depression varied markedly (4%-31%) among subscales. Fatigue levels were very high in this population. The lack of significant correlation between some subscales indicates that they measure different aspects of fatigue. This is also supported by the differences in associations between fatigue subscales and depression and anxiety.

Expectations to and evaluation of a palliative home-care team as seen by patients and carers

OBJECTIVES

Although the number of palliative home-care teams is increasing, knowledge of what patients and principal informal carers expect from a home-care team is sparse. We aimed to elucidate this as well as evaluate a home-care team.

PATIENTS AND METHODS

Individual semi-structured interviews with nine patients and six carers before receiving home care and 2-4 weeks after. In total, 26 interviews were conducted. Interviews were analysed with Template Analysis. Peer debriefing was performed.

MAIN RESULTS

Patients and carers expected the team members to have specialised knowledge in palliative care and to improve their sense of security being at home. They also expected respite for carers and activities for patients. They evaluated the team positively but missed respite for carers and 24-h on-call service.

CONCLUSIONS

Patients and carers found the home-care team essential to their sense of security being at home. Primary health care professionals must receive any necessary training outside patients' homes. Offering respite for carers and 24-h on-call service would be an improvement.

Assessing health-related quality of life in palliative care: comparing patient and physician assessments

It is often difficult to recruit patients for palliative care studies and severe attrition must be expected resulting in biased findings. This may be avoided if equivalent information could be obtained from sources other than the patients. Therefore, we investigated whether physician assessments can be used to evaluate the patients' health-related quality of life (HRQOL). Patient and physician assessments of the patients' HRQOL were obtained once a week for up to 13 weeks using EORTC QLQ-C30 items. The agreement between patients and physicians at first contact (N=115) and for the following 13 weeks combined (total N=263) was investigated. Significant differences between patient and physician assessments were observed for all HRQOL domains assessed. Physicians reported patients to have fewer problems/symptoms than patients did for all HRQOL domains except for physical and social functioning. The agreement between patients and physicians was poor. Using physician assessments may bias findings and cannot be recommended as a substitute for patient self-assessment in palliative care.

Quality of life in patients with benign thyroid disorders. A review

The importance of patient-reported outcomes such as health-related quality of life (HRQL) in clinical research is increasingly acknowledged. In order to yield valid results, the measurement properties of HRQL questionnaires must be thoroughly investigated. One aspect of such a validation process is the demonstration of content validity, i.e. that the questionnaire covers all relevant aspects. We review studies reporting on consequences of thyroid disorders and present the frequency of identified aspects, both overall HRQL issues and classical thyroid symptoms, in order to evaluate which issues are relevant for patients with thyroid diseases. Furthermore, existing questionnaires for thyroid patients are reviewed. A systematic search was performed in the Medline, Cinahl and Psycinfo databases and the reference lists of the relevant articles were hand-searched. Seventy-five relevant studies were identified. According to these studies, patients with untreated thyroid disease suffer from a wide range of symptoms and have major impairment in most areas of HRQL. Furthermore, the studies indicate that impairments in HRQL are also frequent in the long term. Six HRQL questionnaires for thyroid patients were identified. Generally, data supporting the validity of these questionnaires were sparse. According to the available literature, the quality of life of thyroid patients is substantially impaired over a wide range of aspects of HRQL in the untreated phase and continues to be so in many patients also in the long term. Studies systematically exploring the relative importance of these various aspects to thyroid patients are lacking, as is a comprehensive, validated thyroid-specific HRQL questionnaire.

Multidimensional Computerized Adaptive Testing of the EORTC QLQ-C30: Basic Developments and Evaluations

OBJECTIVE

Self-report questionnaires are widely used to measure health-related quality of life (HRQOL). Ideally, such questionnaires should be adapted to the individual patient and at the same time scores should be directly comparable across patients. This may be achieved using computerized adaptive testing (CAT). Usually, CAT is carried out for a single domain at a time. However, many HRQOL domains are highly correlated. Multidimensional CAT may utilize these correlations to improve measurement efficiency. We investigated the possible advantages and difficulties of multidimensional CAT.

STUDY DESIGN AND SETTING

We evaluated multidimensional CAT of three scales from the EORTC QLQ-C30: the physical functioning, emotional functioning, and fatigue scales. Analyses utilised a database with 2958 European cancer patients.

RESULTS

It was possible to obtain scores for the three domains with five to seven items administered using multidimensional CAT that were very close to the scores obtained using all 12 items and with no or little loss of measurement precision.

CONCLUSION

The findings suggest that multidimensional CAT may significantly improve measurement precision and efficiency and encourage further research into multidimensional CAT. Particularly, the estimation of the model underlying the multidimensional CAT and the conceptual aspects need further investigations.

Chemotherapy versus ovarian ablation as adjuvant therapy for breast cancer: impact on health-related quality of life in a randomized trial

BACKGROUND

Ovarian ablation is an effective adjuvant therapy for primary breast cancer but little is known about its quality of life impact relative to the more widely used adjuvant chemotherapy. This randomized study compared quality of life outcomes of adjuvant ovarian ablation versus cyclophosphamide, methotrexate, fluoracil (CMF) chemotherapy.

METHODS

The Danish Breast Cancer Cooperative Group (DBCG) trial 89-b randomized premenopausal patients with receptor-positive, primary breast cancer between nine cycles of CMF chemotherapy given every 3 weeks and ovarian ablation by oophorectomy. In total, 317 randomized patients were invited to take part in a longitudinal quality of life study with assessments at 1, 3, 5, 9, 15, and 24 months after randomization. The questionnaire included the EORTC QLQ-C30, the Hospital Anxiety and Depression Scale, and additional items assessing potential symptoms not included in the standard instruments.

RESULTS

After 2 years, 260 women were alive and recurrence-free, and 196 of these (75%) had completed all six questionnaires. Overall, patients in the chemotherapy group had more symptomatology at the first three assessments (i.e., during the 6 months treatment period), except for hot flushes/sweats. There were few differences between groups at later assessments. In chemotherapy patients, the likelihood of preserving ovarian function decreased steeply with increasing age. CMF chemotherapy and ovarian ablation have similar impact on recurrence and survival.

CONCLUSION

Chemotherapy had more negative impact on health-related quality of life but preserved ovarian function in some younger patients.

Symptom priority and course of symptomatology in specialized palliative care

The study aim was to explore which symptoms/problems cancer patients in palliative care consider most distressing, and to investigate how prioritization at first contact was associated with patient-assessed symptom intensity and change in intensity over time. Initially, 175 patients named and prioritized their five most distressing symptoms. Weekly, they completed the following self-assessment questionnaires: European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30, Edmonton Symptom Assessment System, and the Hospital Anxiety and Depression Scale. Initial symptom intensity scores and weekly changes were calculated and compared with prioritization of the same symptom. Pain, fatigue, physical function, appetite, nausea/vomiting, dyspnea, and depression were the symptoms most often prioritized. Priority was associated with initial scoring of pain, appetite, nausea/vomiting, dyspnea, constipation, depression, and anxiety, but not with fatigue, physical function, role function, or inactivity. Priority was associated with change in symptom intensity for pain, reduced appetite, nausea/vomiting, and constipation. Symptom prioritization may be a useful guide to choice of treatment as well as to longitudinal symptom evaluation.

Item response theory was used to shorten EORTC QLQ-C30 scales for use in palliative care

BACKGROUND AND OBJECTIVE

The goal was to develop a shortened version of the EORTC QLQ-C30 for use in palliative care. We wanted to keep as few items as possible in each scale while still being able to compare results with studies using the original scales. We examined the possibilities of shortening the physical functioning, cognitive functioning, fatigue, and nausea and vomiting scales.

STUDY DESIGN AND SETTING

The shortening was based on 2,366 (physical functioning) and 10,815 (three other scales) observations, respectively. We used item response theory to construct scoring algorithms for predicting scores on the original scales.

RESULTS

Evaluations showed that a three-item physical scale, a two-item fatigue scale, and a one-item nausea or vomiting scale predicted the scores on the original scales with excellent agreement and had measurement abilities similar to the original scales with no loss or only a little loss in power to detect group differences. The results of the cognitive functioning scale indicated problems when predicting scores from a shortened version.

CONCLUSION

Given the favorable results for the physical functioning, fatigue, and nausea or vomiting scales we expect that the shortened versions of these scales will be included in the abbreviated version of the EORTC QLQ-C30 for palliative care.

Scoring based on item response theory did not alter the measurement ability of EORTC QLQ-C30 scales

BACKGROUND AND OBJECTIVES

Most health-related quality-of-life questionnaires include multi-item scales. Scale scores are usually estimated as simple sums of the item scores. However, scoring procedures utilizing more information from the items might improve measurement abilities, and thereby reduce the needed sample sizes. We investigated whether item response theory (IRT)-based scoring improved the measurement abilities of the EORTC QLQ-C30 physical functioning, emotional functioning, and fatigue scales.

METHODS

Using a database of 13,010 subjects we estimated the relative validities of IRT scoring compared to sum scoring of the scales.

RESULTS

The mean relative validities were 1.04 (physical), 1.03 (emotional), and 0.97 (fatigue). None of these were significantly larger than 1. Thus, no gain in measurement abilities using IRT scoring was found for these scales. Possible explanations include that the items in the scales are not constructed for IRT scoring and that the scales are relatively short.

CONCLUSION

IRT scoring of the three longest EORTC QLQ-C30 scales did not improve measurement abilities compared to the traditional sum scoring of the scales.

The development of the EORTC QLQ-C15-PAL: a shortened questionnaire for cancer patients in palliative care

This study aimed at developing a shortened version of the EORTC QLQ-C30, one of the most widely used health-related quality of life questionnaires in oncology, for palliative care research. The study included interviews with 41 patients and 66 health care professionals in palliative care to determine the appropriateness, relevance and importance of the various domains of the QLQ-C30. Item response theory methods were used to shorten scales. Patients and health care professionals rated pain, physical function, emotional function, fatigue, global health status/quality of life, nausea/vomiting, appetite, dyspnoea, constipation, and sleep as most important. Therefore, these scales/items were retained in the questionnaire. Four scales were shortened without reducing measurement precision. Important dimensions not covered by the questionnaire were identified. The resulting 15-item EORTC QLQ-C15-PAL is a 'core questionnaire' for palliative care. Depending on the research questions, it may be supplemented by additional items, modules or questionnaires.

Cooperating with a palliative home-care team: expectations and evaluations of GPs and district nurses

BACKGROUND

Palliative home-care teams often cooperate with general practitioners (GPs) and district nurses. Our aim was to evaluate a palliative home-care team from the viewpoint of GPs and district nurses.

METHODS

GPs and district nurses received questionnaires at the start of home-care and one month later. Questions focussed on benefits to patients, training issues for professionals and cooperation between the home-care team and the GP/ district nurse. A combination of closed- and open-ended questions was used.

RESULTS

Response rate was 84% (467/553). Benefits to patients were experienced by 91 %, mainly due to improvement in symptom management, 'security', and accessibility of specialists in palliative care. After one month, 57% of the participants reported to have learnt aspects of palliative care, primarily symptom control, and 89% of them found cooperation satisfactory. Dissatisfaction was caused mainly by lack of information from the home-care team to primary-care professionals.

CONCLUSION

GPs and district nurses welcomed the palliative home-care team and most experienced benefits to patients. Strengthened communication, initiated by the home-care team would enhance cooperation.

A longitudinal study of palliative care

BACKGROUND

The current article evaluated the course of patient-assessed symptomatology in specialized palliative care and tested for bias due to patient attrition in measures of initial symptomatology and treatment outcome.

METHODS

Over 2 years, 267 consecutive, eligible patients were referred to a department of palliative care. Upon arrival, 201 patients consented to participate in a questionnaire-based evaluation of quality of life (QOL). Of these, 175 patients participated, and 142, 119, and 95 participated in the study at 1, 2, and 3 weeks, respectively. Weekly, participants completed the self-assessment questionnaires European Organization for Research and Treatment of Cancer QLQ-C30, Edmonton Symptom Assessment System, Hospital Anxiety and Depression Scale, and Multidimensional Fatigue Inventory. Physicians used the Mini Mental State Examination to evaluate cognitive function. Changes from the initial symptom scores for each week were calculated. Initial scoring and change after 1 week were tested for association with completion level, i.e., whether the patient completed questions at 1, 2, 3, or 4 time points.

RESULTS

High initial symptom intensity and significant improvements over time were observed for pain, lack of appetite, nausea/vomiting, sleeplessness, constipation, and overall QOL/well-being. For some symptoms, initial scores were significantly higher in patients who dropped out, but the changes over the first week were not significantly different between completion levels for any symptom.

CONCLUSIONS

Improvement in symptom intensity was identified. Dropout was associated with higher initial symptomatology but not with poorer outcome of palliative treatment.

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.

Validation of a questionnaire for self-assessment of sexual function and vaginal changes after gynaecological cancer

The Sexual function-Vaginal changes Questionnaire (SVQ), was developed to investigate sexual and vaginal problems in gynaecological cancer patients. The instrument consists of 20 core items, measuring sexual interest, lubrication, orgasm, dyspareunia, vaginal dimensions, intimacy, sexual problems of partner, sexual activity, sexual satisfaction, and body image. Seven additional items assessing current levels of sexual and vaginal problems compared to pre-diagnosis are intended to be used only once in longitudinal studies. The SVQ was validated in two ways: first, the comprehensibility of each item was investigated through combined quantitative and qualitative assessment of patient-observer agreement in 75 gynaecological cancer patients, second, multitrait analyses and principal component analyses were applied to responses from 257 patients with cervical cancer to investigate the scale properties. The level of agreement between the patients' and the observer's ratings was high (median overall agreement 0.84, range 0.46-1.00; median kappa: 0.80, range 0.52-1.00). From the 10 items applicable to all patients, three scales were hypothesized: intimacy, sexual interest and global sexual satisfaction. For sexually active respondents an additional two scales were hypothesized: vaginal changes and sexual functioning. The psychometric analyses confirmed these scales. The internal consistency of the scales ranged 0.76-0.83 (Cronbach's alpha). The study supports the validity and reliability of the SVQ.

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.

Pain characteristics and treatment outcome for advanced cancer patients during the first week of specialized palliative care

To examine pain in cancer patients referred for specialized palliative care, we described pain characteristics and medication on admission, examined changes in pain during the first week, and searched for predictors of initial pain intensity and treatment outcome. On arrival in the department (T0) and after one week (T1), pain was evaluated with the Edmonton Symptom Assessment System (ESAS) and EORTC QLQ-C30. Analgesics were recorded. We investigated the associations between initial pain scores as well as differences from T0 to T1, and clinical and sociodemographic parameters, initial medication, and medical interventions. Of 267 eligible patients, initial pain scores were obtained from 175. Initial pain scores were high, although 81% of patients received opioid treatment at T0. Bone metastases, neuropathic pain, mixed pain pathophysiology, and breakthrough pain were associated with higher initial pain scores. Pain scores decreased during the first week. No single parameter convincingly predicted a better or worse outcome of pain treatment.

Longitudinal study of sexual function and vaginal changes after radiotherapy for cervical cancer

PURPOSE

To investigate the longitudinal course of self-reported sexual function and vaginal changes in patients disease free after radiotherapy (RT) for locally advanced, recurrent, or persistent cervical cancer.

MATERIALS AND METHODS

A total of 118 patients referred for RT were included. The patients were assessed, using a validated self-assessment questionnaire, at the termination of RT and 1, 3, 6, 12, 18, and 24 months later. The results were compared with an age-matched control group from the general population.

RESULTS

Persistent sexual dysfunction and adverse vaginal changes were reported throughout the 2 years after RT, with small changes over time: approximately 85% had low or no sexual interest, 35% had moderate to severe lack of lubrication, 55% had mild to severe dyspareunia, and 30% were dissatisfied with their sexual life. A reduced vaginal dimension was reported by 50% of the patients, and 45% were never, or only occasionally, able to complete sexual intercourse. Despite sexual dysfunction and vaginal adverse effects, 63% of those sexually active before having cancer remained sexually active after treatment, although with a considerably decreased frequency.

CONCLUSIONS

Patients who are disease free after RT for locally advanced, recurrent, or persistent cervical cancer are at high risk of experiencing persistent sexual and vaginal problems compromising their sexual activity and satisfaction.

Use of differential item functioning analysis to assess the equivalence of translations of a questionnaire

In cross-national comparisons based on questionnaires, accurate translations are necessary to obtain valid results. Differential item functioning (DIF) analysis can be used to test whether translations of items in multi-item scales are equivalent to the original. In data from 10,815 respondents representing 10 European languages we tested for DIF in the nine translations of the EORTC QLQ-C30 emotional function scale when compared to the original English version. We tested for DIF using two different methods in parallel, a contingency table method and logistic regression. The DIF results obtained with the two methods were similar. We found indications of DIF in seven of the nine translations. At least two of the DIF findings seem to reflect linguistic problems in the translation. 'Imperfect' translations can affect conclusions drawn from cross-national comparisons. Given that translations can never be identical to the original we discuss how findings of DIF can be interpreted and discuss the difference between linguistic DIF and DIF caused by confounding, cross-cultural differences, or DIF in other items in the scale. We conclude that testing for DIF is a useful way to validate questionnaire translations.

Early-stage cervical carcinoma, radical hysterectomy, and sexual function

BACKGROUND

Limited knowledge exists concerning the impact of radical hysterectomy (RH) alone on the sexual function of patients with early-stage cervical carcinoma. The authors investigated the longitudinal course of self-reported sexual function after RH.

METHODS

The current study was comprised of 173 patients with lymph node-negative, early-stage cervical carcinoma who had undergone RH and pelvic lymphadenectomy. They were assessed prospectively using a validated self-assessment questionnaire 5 weeks and 3 months, 6 months, 12 months, 18 months, and 24 months after RH. Results were compared with an age-matched control group from the general population.

RESULTS

Compared with control women, patients experienced severe orgasmic problems and uncomfortable sexual intercourse due to a reduced vaginal size during the first 6 months after RH, severe dyspareunia during the first 3 months, and sexual dissatisfaction during the 5 weeks after RH. A persistent lack of sexual interest and lubrication were reported throughout the first 2 years after RH. Long-term lack of sexual interest and insufficient vaginal lubrication were confirmed by the patient's self-reported changes 12 months after RH compared with before the cancer diagnosis and by a pre-post comparison within patients. However, most of the patients who were sexually active before their cancer diagnosis were sexually active again 12 months after surgery (91%), although with a decrease in sexual frequency reported.

CONCLUSIONS

RH had a persistent and negative impact on patients' sexual interest and vaginal lubrication whereas the majority of other sexual and vaginal problems disappeared over time. Sexual and vaginal problems in the short-term and long-term after RH should be discussed with the patient before and after surgery.

Validation of a questionnaire for self-rating of urological and gynaecological morbidity after treatment of gynaecological cancer

BACKGROUND AND PURPOSE

Patient self-assessment of symptom severity provides clinicians and researchers with important information. It is crucial to evaluate the validity of a self-assessment questionnaire in the context of its intended use. The objective of this study was to evaluate the validity of the uro-gynaecological questionnaire (UGQ), a new instrument for patient self-assessment of urological-, genital-, menopausal-, and pain symptomatology in gynaecological cancer patients.

MATERIAL AND METHODS

The UGQ was developed after literature review, patient- and expert interviews and pilot testing. From February 1992 to October 1992, 88 gynaecological cancer patients were invited to participate in a validation study after the initiation of their primary radiotherapy or chemotherapy. The method of validation investigated whether patients and researchers interpreted the items of the questionnaire in the same way. The patient's written response before interview was compared with an observer rating of the patient's open-ended audio-taped responses to the same questionnaire, administered as an interview. Qualitative recordings by the observer were made to describe potential misinterpretations.

RESULTS

The agreement between the patient's and the observer's ratings was high: the median overall agreement was 0.91 (range 0.71-1.00) and the median kappa was 0.88 (range 0.45-1.00). The quantitative and the qualitative results identified a few minor validity problems; especially, the issue of selective reporting, i.e. some patients only reporting those symptoms they considered relevant for the study, which may lead to systematic errors.

CONCLUSIONS

The results strongly suggest that patients interpret the UGQ items as intended, i.e. they are valid. The UGQ is recommended for patient self-assessment of uro-gynaecological morbidity in gynaecological cancer patients.

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.

Fatigue and physical function after orthotopic liver transplantation

Over the last two decades, orthotopic liver transplantation (OLT) has become an established treatment for acute and chronic liver failure. OLT impacts not only on survival, but also on health-related quality of life. This study was undertaken to describe the self-rated health of Danish liver transplant recipients, compare their self-rated health against that of the general population, and to investigate associations between sex, age, diagnosis, time after OLT, and postoperative physical function and fatigue. All adult surviving liver transplant recipients who underwent OLT in Copenhagen, Denmark, from 1990 to 1998 (n = 154) were contacted by mail and asked to complete a self-administered questionnaire. The questionnaire contained the 36-Item Short Form Health Survey, the Multidimensional Fatigue Inventory, the Hospital Anxiety and Depression Scale, and questions on marital status, education, and work. The response rate was 84.4% (n = 130). Liver transplant recipients reported poorer self-rated health than the general population in physical, but not in mental, health areas. One health aspect, fatigue, was investigated in great detail. This study found that liver transplant recipients experienced physical, rather than mental, fatigue. Diagnosis was found to be a predictor of postoperative physical function and fatigue because patients with an alcoholic or cryptogenic cirrhosis background had significantly poorer physical function and experienced more physical fatigue than liver transplant recipients with other diagnoses. Work status and survival time after OLT had significant effects on postoperative physical function and fatigue. Working and having undergone transplantation 4 to 5 years previously were associated with significantly better physical function and less physical fatigue than not working and having undergone transplantation 1 to 3 years previously. This study suggests that liver transplant recipients experience physical, rather than mental, impairment and fatigue and that diagnosis, work status, and survival time after OLT are associated with physical function and fatigue.

Self-assessment in cancer patients referred to palliative care: a study of feasibility and symptom epidemiology

BACKGROUND

Research in palliative care is considered difficult due to the poor health of patients. However, patient-provided data are essential for a thorough description of patient symptomatology and for the evaluation of care.

METHODS

The authors examined the feasibility of a questionnaire-based study using the European Organization for Research and Treatment of Cancer quality-of-life instrument EORTC QLQ-C30, the Edmonton Symptom Assessment System (ESAS), and the Hospital Anxiety and Depression Scale (HADS) in cancer patients who were receiving palliative care. This report describes the symptomatology of participating patients and examines differences in symptomatology between patients in three palliative care functions: inpatient, outpatient, and palliative home care.

RESULTS

Of 267 eligible patients who were referred to a department of palliative medicine, initial self-assessment questionnaires were obtained from 176 patients (65.9%). The 91 nonparticipants were older and had lower Karnofsky Performance status (KPS) values than the participants. Almost all participating patients suffered from impaired role function and physical function and had high levels of pain, fatigue, and other symptoms. According to the HADS, 47% of patients suffered from depression. Outpatients had better scores than inpatients and patients in palliative home care for physical function, role function, cognitive function, depression, and inactivity.

CONCLUSIONS

It is possible to carry out a questionnaire-based study of symptomatology in consecutive cancer patients in palliative care, achieving rather complete data from the participants. The symptomatology in these patients was very pronounced. The questionnaires were able to detect clinically important differences between places of service.

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.