General population normative values for the EORTC QLQ-C30 by age, sex, and health condition for the French general population.

BACKGROUND: General population normative values for the widely used health-related quality of life (HRQoL) measure EORTC QLQ-C30 support the interpretation of trial results and HRQoL of patients in clinical practice. Here, we provide sex-, age- and health condition-specific normative values for the EORTC QLQ-C30 in the French general population. METHODS: French general population data was collected in an international EORTC project. Online panels with quota samples were used to recruit sex and age groups. Number and type of comorbidities were assessed. Descriptive statistics were used to calculate general population values for each QLQ-C30 scale, separately for sex, age, and presence of one- and more chronic health conditions. A multivariate linear regression model has been developed to allow estimating the effect of sex, age, and the presence for one- and more chronic health conditions on EORTC QLQ-C30 scores. Data was weighted according to United Nation statistics adjusting for the proportion of sex and age groups. RESULTS: In total, 1001 French respondents were included in our analyses. The weighted mean age was 47.9 years, 514 (51.3%) participants were women, and 497 (52.2%) participants reported at least one health condition. Men reported statistically significant better scores for Emotional Functioning (+9.6 points, p = 0.006) and Fatigue (-7.8 point; p = 0.04); women reported better profiles for Role Functioning (+8.7 points; p = 0.008) and Financial Difficulty (-7.8 points, p = 0.011). According to the regression model, the sex effect was statistically significant in eight scales; the effect of increasing age had a statistically significant effect on seven of the 15 EORTC QLQ-C30 scales. The sex- and age effect varied in its direction across the various scales. The presence of health conditions showed a strong negative effect on all scales. CONCLUSION: This is the first publication of detailed French normative values for the EORTC QLQ-C30. It aims to support the interpretation of HRQoL profiles in French cancer populations. The strong impact of health conditions on QLQ-C30 scores highlights the importance of considering the impact of comorbidities in cancer patients when interpreting HRQoL data.

EORTC QLQ-C30 normative data for the United Kingdom: Results of a cross-sectional survey of the general population.

OBJECTIVE: The cancer-specific health-related quality of life (HRQoL) questionnaire of the European Organisation for Research and Treatment of Cancer (EORTC), the EORTC QLQ-C30, is a frequently applied questionnaire to assess cancer patients' self-reported health used as part of research and clinical practice. Normative data obtained from the general population can facilitate the interpretation of these data. Despite its frequent application, no detailed EORTC QLQ-C30 normative data have yet been published for the United Kingdom (UK). This study presents detailed EORTC QLQ-C30 normative data for the United Kingdom overall and by sex and age. METHODS: The data are drawn from a larger published, international, cross-sectional online survey. For the recruitment, the sample was stratified by sex (males, females) and age in five age groups with a sample size of n = 100 per subgroup. RESULTS: A total of N = 1026 UK respondents completed the survey (n = 517 females, n = 509 males). There were no clear subgroup patterns by sex or age; however, older patients tended to show higher (i.e., better) scores in emotional and social functioning; they also reported some of the lowest (i.e., best) scores for symptoms, such as insomnia, appetite loss, diarrhoea, nausea/vomiting or financial difficulties. CONCLUSION: This paper provides EORTC QLQ-C30 general population normative data for the UK, further stratified by sex and age. These data will greatly support the interpretation of EORTC QLQ-C30 scale scores obtained from UK cancer patients, and also enable comparison with other detailed national normative datasets collected in the same project, across several other European countries and the US.

EORTC QLQ-C30 general population normative data for the United States.

OBJECTIVE: The European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 is a frequently used cancer-specific health-related quality of life (HRQoL) questionnaire. To aid interpretation of data obtained via EORTC QLQ-C30, general population norm data have been published for many countries. However, despite its frequent use in the United States, no normative data by sex and age exist to date. Therefore, this study aimed to generate sex- and age-specific EORTC QLQ-C30 normative data for the United States. METHODS: Recruitment and data collection were carried out via online panels as part of a larger cross-sectional study. For the recruitment, the sample was stratified by sex and age (18-39, 40-49, 50-59, 60-69, ≥ 70 years) to achieve a balanced distribution, with n = 100 per subgroup. Descriptive statistics are presented by age and age/sex. RESULTS: A total of N = 1009 respondents completed the survey (n = 508 females, n = 501 males). More than two thirds of participants (72.5%) reported at least one health condition, e.g., arthritis (26%). Across EORTC QLQ-C30 scales, women and men 60 years and older reported generally better/higher functioning and better/lower symptom scores compared to the younger age groups. CONCLUSION: To date, no specific EORTC QLQ-C30 general population normative data have been published for the United States. This paper provides these important normative data, which will greatly support the interpretation of EORTC QLQ-C30 scale scores obtained from US cancer patients, and also enable comparison with European norms.

How Are Age, Gender, and Country Differences Associated With PROMIS Physical Function, Upper Extremity, and Pain Interference Scores?

BACKGROUND: The interpretation of patient-reported outcomes requires appropriate comparison data. Currently, no patient-specific reference data exist for the Patient-Reported Outcome Measurement Information System (PROMIS) Physical Function (PF), Upper Extremity (UE), and Pain Interference (PI) scales for individuals 50 years and older. QUESTIONS/PURPOSES: (1) Can all PROMIS PF, UE, and PI items be used for valid cross-country comparisons in these domains among the United States, the United Kingdom, and Germany? (2) How are age, gender, and country related to PROMIS PF, PROMIS UE, and PROMIS PI scores? (3) What is the relationship of age, gender, and country across individuals with PROMIS PF, PROMIS UE, and PROMIS PI scores ranging from very low to very high? METHODS: We conducted telephone interviews to collect custom PROMIS PF (22 items), UE (eight items), and PI (eight items) short forms, as well as sociodemographic data (age, gender, work status, and education level), with participants randomly selected from the general population older than 50 years in the United States (n = 900), United Kingdom (n = 905), and Germany (n = 921). We focused on these individuals because of their higher prevalence of surgeries and lower physical functioning. Although response rates varied across countries (14% for the United Kingdom, 22% for Germany, and 12% for the United States), we used existing normative data to ensure demographic alignment with the overall populations of these countries. This helped mitigate potential nonresponder bias and enhance the representativeness and validity of our findings. We investigated differential item functioning to determine whether all items can be used for valid crosscultural comparisons. To answer our second research question, we compared age groups, gender, and countries using median regressions. Using imputation of plausible values and quantile regression, we modeled age-, gender-, and country-specific distributions of PROMIS scores to obtain patient-specific reference values and answer our third research question. RESULTS: All items from the PROMIS PF, UE, and PI measures were valid for across-country comparisons. We found clinically meaningful associations of age, gender, and country with PROMIS PF, UE, and PI scores. With age, PROMIS PF scores decreased (age ß Median = -0.35 [95% CI -0.40 to -0.31]), and PROMIS UE scores followed a similar trend (age ß Median = -0.38 [95% CI -0.45 to -0.32]). This means that a 10-year increase in age corresponded to a decline in approximately 3.5 points for the PROMIS PF score-a value that is approximately the minimum clinically important difference (MCID). Concurrently, we observed a modest increase in PROMIS PI scores with age, reaching half the MCID after 20 years. Women in all countries scored higher than men on the PROMIS PI and 1 MCID lower on the PROMIS PF and UE. Additionally, there were higher T-scores for the United States than for the United Kingdom across all domains. The difference in scores ranged from 1.21 points for the PROMIS PF to a more pronounced 3.83 points for the PROMIS UE. Participants from the United States exhibited up to half an MCID lower T-scores than their German counterparts for the PROMIS PF and PROMIS PI. In individuals with high levels of physical function, with each 10-year increase in age, there could be a decrease of up to 4 points in PROMIS PF scores. Across all levels of upper extremity function, women reported lower PROMIS UE scores than men by an average of 5 points. CONCLUSION: Our study provides age-, gender-, and country-specific reference values for PROMIS PF, UE, and PI scores, which can be used by clinicians, researchers, and healthcare policymakers to better interpret patient-reported outcomes and provide more personalized care. These findings are particularly relevant for those collecting patient-reported outcomes in their clinical routine and researchers conducting multinational studies. We provide an internet application ( www.common-metrics.org/PROMIS_PF_and_PI_Reference_scores.php ) for user-friendly accessibility in order to perform age, gender, and country conversions of PROMIS scores. Population reference values can also serve as comparators to data collected with other PROMIS short forms or computerized adaptive tests. LEVEL OF EVIDENCE: Level II, diagnostic study.

Overcoming floor and ceiling effects in knee arthroplasty outcome measurement.

Aims: To map the Oxford Knee Score (OKS) and High Activity Arthroplasty Score (HAAS) items to a common scale, and to investigate the psychometric properties of this new scale for the measurement of knee health. Methods: Patient-reported outcome measure (PROM) data measuring knee health were obtained from the NHS PROMs dataset and Total or Partial Knee Arthroplasty Trial (TOPKAT). Assumptions for common scale modelling were tested. A graded response model (fitted to OKS item responses in the NHS PROMs dataset) was used as an anchor to calibrate paired HAAS items from the TOPKAT dataset. Information curves for the combined OKS-HAAS model were plotted. Bland-Altman analysis was used to compare common scale scores derived from OKS and HAAS items. A conversion table was developed to map between HAAS, OKS, and the common scale. Results: We included 3,329 response sets from 528 patients undergoing knee arthroplasty. These generally met the assumptions of unidimensionality, monotonicity, local independence, and measurement invariance. The HAAS items provided more information than OKS items at high levels of knee health. Combining both instruments resulted in higher test-level information than either instrument alone. The mean error between common scale scores derived from the OKS and HAAS was 0.29 logits. Conclusion: The common scale allowed more precise measurement of knee health than use of either the OKS or HAAS individually. These techniques for mapping PROM instruments may be useful for the standardization of outcome reporting, and pooling results across studies that use either PROM in individual-patient meta-analysis.

Measuring PROMIS pain interference in German patients with chronic conditions: calibration, validation, and cross-cultural use of item parameters.

PURPOSE: To calibrate the item parameters of the German PROMIS® Pain interference (PROMIS PI) items using an item-response theory (IRT) model and investigate psychometric properties of the item bank. METHODS: Forty items of the PROMIS PI item bank were collected in a convenience sample of 660 patients, which were recruited during inpatient rheumatological treatment or outpatient psychosomatic medicine visits in Germany. Unidimensionality, monotonicity, and local independence were tested as required for IRT analyses. Unidimensionality was examined using confirmatory factor analyses (CFA) and exploratory factor analysis (EFA). Unidimensional and bifactor graded-response IRT models were fitted to the data. Bifactor indices were used to investigate whether multidimensionality would lead to biased scores. To evaluate convergent and discriminant validity, the item bank was correlated with legacy pain instruments. Potential differential item functioning (DIF) was examined for gender, age, and subsample. To investigate whether U.S. item parameters may be used to derive T-scores in German patients, T-scores based on previously published U.S. and newly estimated German item parameters were compared with each other after adjusting for sample specific differences. RESULTS: All items were sufficiently unidimensional, locally independent, and monotonic. Whereas the fit of the unidimensional IRT model was not acceptable, a bifactor IRT model demonstrated acceptable fit. Explained common variance and Omega hierarchical suggested that using the unidimensional model would not lead to biased scores. One item demonstrated DIF between subsamples. High correlations with legacy pain instruments supported construct validity of the item bank. T-scores based on U.S. and German item parameters were similar suggesting that U.S. parameters could be used in German samples. CONCLUSION: The German PROMIS PI item bank proved to be a clinically valid and precise instrument for assessing pain interference in patients with chronic conditions.

Suitability of the animated activity questionnaire for use as computer adaptive test: establishing the AAQ-CAT.

PURPOSE: The animated activity questionnaire (AAQ) is a computer-based measure of activity limitations. To answer a question, patients choose the animation of a person performing an activity that matches their own level of limitation. The AAQ has not yet been tested for suitability to be applied as computer-adaptive test (CAT). Thus, the objective of this study was to develop and evaluate an AAQ-based CAT to facilitate the application of the AAQ in daily clinical care. METHODS: Patients (n = 1408) with hip/knee osteoarthritis from Brazil, Denmark, France, The Netherlands, Norway, Spain, and the UK responded to all 17 AAQ items. Assumptions of item-response theory (IRT) modelling were investigated. To establish item parameters for the CAT, a graded response model was estimated. To evaluate the performance of post-hoc simulated AAQ-based CATs, precision, test length, and construct validity (correlations with well-established measures of activity limitations) were evaluated. RESULTS: Unidimensionality (CFI = 0.95), measurement invariance (R2-change < 2%), and IRT item fit (S-X2 p > .003) of the AAQ were supported. Performing simulated CATs, the mean test length was more than halved (≤ 8 items), while the range of precise measurement (standard error ≤ 0.3) was comparable to the full AAQ. The correlations between original AAQ scores and three AAQ-CAT versions were ≥ 0.95. Correlations of AAQ-CAT scores with patient-reported and performance measures of activity limitations were ≥ 0.60. CONCLUSION: The almost non-verbal AAQ-CAT is an innovative and efficient tool in patients with hip/knee osteoarthritis from various countries, measuring activity limitations with lower respondent burden, but similar precision and construct validity compared to the full AAQ.

Item response theory assumptions were adequately met by the Oxford hip and knee scores.

OBJECTIVES: To develop item response theory (IRT) models for the Oxford hip and knee scores which convert patient responses into continuous scores with quantifiable precision and provide these as web applications for efficient score conversion. STUDY DESIGN AND SETTING: Data from the National Health Service patient-reported outcome measures program were used to test the assumptions of IRT (unidimensionality, monotonicity, local independence, and measurement invariance) before fitting models to preoperative response patterns obtained from patients undergoing primary elective hip or knee arthroplasty. The hip and knee datasets contained 321,147 and 355,249 patients, respectively. RESULTS: Scree plots, Kaiser criterion analyses, and confirmatory factor analyses confirmed unidimensionality and Mokken analysis confirmed monotonicity of both scales. In each scale, all item pairs shared a residual correlation of ≤ 0.20. At the test level, both scales showed measurement invariance by age and gender. Both scales provide precise measurement in preoperative settings but demonstrate poorer precision and ceiling effects in postoperative settings. CONCLUSION: We provide IRT parameters and web applications that can convert Oxford Hip Score or Oxford Knee Score response sets into continuous measurements and quantify individual measurement error. These can be used in sensitivity analyses or to administer truncated and individualized computerized adaptive tests.

Physical performance tasks were linked to the PROMIS physical function metric in patients undergoing hemodialysis.

OBJECTIVES: To investigate whether a multi-item performance outcome measure, the physical performance test (PPT), can be calibrated to a common scale with patient-reported outcome measures, using the Patient-Reported Outcomes Measurement Information System (PROMIS) physical function (PF) metric. STUDY DESIGN AND SETTING: We analyzed baseline data (N = 1,113) from the CONVINCE study, an international trial in end-stage kidney disease patients comparing high-dose hemodiafiltration with high-flux hemodialysis. Assumptions of item response theory (IRT) modelling were investigated for the combined set of the nine-item PPT and a four-item PROMIS PF short form (PROMIS-PF4a). We applied unidimensional IRT linking for calibrating the PPT to the PROMIS PF metric. RESULTS: Although some evidence for multidimensionality was found, classical test statistics (Cronbach's Alpha = 0.93), Mokken (Loevinger's H = 0.50), and bifactor analysis (explained common variance = 0.65) indicated that PPT and PROMIS-PF4a items can be used to assess a common PF construct. On the group level, the agreement between PROMIS-PF4a and linked PPT scores was stable across several subsamples. On the individual level, scores differed considerably. CONCLUSION: We found preliminary evidence that the PPT can be linked to the PROMIS PF metric in hemodialysis patients, enabling group comparisons across patient-reported outcome and performance outcome measures. Alternative linking methods should be applied in future studies using a more comprehensive PROMIS PF item set.

Item response theory may account for unequal item weighting and individual-level measurement error in trials that use PROMs: a psychometric sensitivity analysis of the TOPKAT trial.

OBJECTIVES: To apply item response theory as a framework for studying measurement error in superiority trials which use patient-reported outcome measures (PROMs). METHODS: We reanalyzed data from the The Total or Partial Knee Arthroplasty Trial, which compared the Oxford Knee Score (OKS) responses of patients undergoing partial or total knee replacement, using traditional sum-scoring, after accounting for OKS item characteristics with expected a posteriori (EAP) scoring, and after accounting for individual-level measurement error with plausible value imputation (PVI). We compared the marginalized mean scores of each group at baseline, 2 months, and yearly for 5 years. We used registry data to estimate the minimal important difference (MID) of OKS scores with sum-scoring and EAP scoring. RESULTS: With sum-scoring, we found statistically significant differences in mean OKS score at 2 months (P = 0.030) and 1 year (P = 0.030). EAP scores produced slightly different results, with statistically significant differences at 1 year (P = 0.041) and 3 years (P = 0.043). With PVI, there were no statistically significant differences. CONCLUSION: Psychometric sensitivity analyses can be readily performed for superiority trials using PROMs and may aid the interpretation of results.

The European Organisation for Research and Treatment of Cancer Quality of Life Utility-Core 10 Dimensions: Development and Investigation of General Population Utility Norms for Canada, France, Germany, Italy, Poland, and the United Kingdom.

OBJECTIVES: The European Organisation for Research and Treatment of Cancer Quality of Life Utility-Core 10 Dimensions (EORTC QLU-C10D) is a cancer-specific preference-based measure, providing health utilities for use in economic evaluations derived from the widely used health-related quality of life measure, EORTC QLQ-C30. Several EORTC QLU-C10D country-specific value sets are available. This article aimed to provide EORTC QLU-C10D general population utility norms for Canada, France, Germany, Italy, Poland, and the United Kingdom, to aid interpretability of obtained utilities in these countries. METHODS: Data were collected in aforementioned countries via a quota-sampled, cross-sectional online survey (n = 100/age-sex group; N = approximately 1000/country). Participants were asked to complete the EORTC QLQ-C30 and provide sociodemographic data. Country-specific utility norms were calculated using the respective country tariff on the country's EORTC QLQ-C30 data after weighting to achieve population representativeness for age and sex. Norm values are provided as means (SDs) by country, age, and sex groups. Tukey's multiple comparison test investigated mean differences among countries. The impact of country, age, and sex on utility values was investigated with a multiple linear regression model. RESULTS: Country-specific mean utilities range from 0.724 (United Kingdom) to 0.843 (Italy). Country-, sex-, and age-specific mean utilities range from 0.664 for 30- to 39-year-old male Canadians to 0.899 for > 70-year-old male Italians. Utilities were lower in females in 4 of 6 countries, and the impact of age differed among countries. Independent of the impact of age and sex, between-country differences were found (P ≤ .05). CONCLUSION: Results showed a varying impact of age and sex on EORTC QLU-C10D utilities and significant between-country differences. Using national utility norms and utility decrements is recommended.

Frequently Used Patient-Reported Outcome Measures of General Physical Function Were Highly Correlated With a Multitask Performance Outcome Test Battery.

OBJECTIVES: This study aimed to determine the relationship between frequently used patient-reported outcome (PRO) measures and a multitask performance outcome (PerfO) measure of general physical function (PF) and to examine the association of these measures with depressive mood, pain, and age. METHODS: Frequently used PRO measures of general PF (Patient-Reported Outcomes Measurement Information System [PROMIS] PF item bank, PROMIS PF Short Form 20a, Short Form 36 Physical Function Scale) and a PerfO test battery, namely, the Physical Performance Test (PPT), were administered to 78 adult patients from 3 inpatient clinics (cardiology and angiology, rheumatology and clinical immunology, and psychosomatic medicine) at Charité - Universitätsmedizin Berlin. Pearson correlations were used to investigate the associations between PRO measures and the PPT. To explore the predictive value of age, depressive symptoms, and pain intensity, we conducted multiple linear regression analysis for each PF measure. RESULTS: We found strong linear relationships between PRO measures and PPT sum scores. Correlations between PPT sum scores and PROMIS PF T-scores were r > 0.75. For all PRO and PerfO measures, age was a predictor of general PF whereas depressive mood was not found to be a relevant predictor. Moreover, pain intensity was found to be a significant predictor of PRO measures but not for PPT sum scores. CONCLUSIONS: Our findings suggest that frequently used PRO measures and a multitask PerfO measure of general PF can be used to measure a common PF construct. Nevertheless, PF scores based on PRO measures should ideally be controlled for self-rated pain intensity.

EORTC QLQ-C30 general population normative data for Italy by sex, age and health condition: an analysis of 1,036 individuals.

BACKGROUND: General population normative values for the widely used health-related quality of life (HRQoL) measure, European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire - Core 30 (EORTC QLQ-C30), are available for a range of countries. These are mostly countries in northern Europe. However, there is still a lack of such normative values for southern Europe. Therefore, this study aims to provide sex-, age- and health condition-specific normative values for the general Italian population for the EORTC QLQ-C30. MATERIAL AND METHODS: This study is based on Italian EORTC QLQ-C30 general population data previously collected in an international EORTC project comprising over 15,000 respondents across 15 countries. Recruitment and assessment were carried out via online panels. Quota sampling was used for sex and age groups (18|-|39, 40-49, 50-59, 60-69 and ≥ 70 years), separately for each country. We applied weights to match the age and sex distribution in our sample with UN statistics for Italy. Along with descriptive statistics, linear regression models were estimated to describe the associations of sex, age and health condition with the EORTC QLQ-C30 scores. RESULTS: A total of 1,036 respondents from Italy were included in our analyses. The weighted mean age was 49.3 years, and 536 (51.7%) participants were female. Having at least one health condition was reported by 60.7% of the participants. Men reported better scores than women on all EORTC QLQ-C30 scales but diarrhoea. While the impact of age differed across scales, older age was overall associated with better HRQoL as shown by the summary score. For all scales, differences were in favour of participants who did not report any health condition, compared to those who reported at least one. CONCLUSION: The Italian normative values for the EORTC QLQ-C30 scales support the interpretation of HRQoL profiles in Italian cancer populations. The strong impact of health conditions on EORTC QLQ-C30 scores highlights the importance of adjusting for the impact of comorbidities in cancer patients when interpreting HRQoL data.

General Spanish population normative data analysis for the EORTC QLQ-C30 by sex, age, and health condition.

PURPOSE: General population normative data for the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 questionnaire facilitates interpretation of data assessed from cancer patients. This study aims to present normative data of the general Spanish population. METHODS/PATIENTS: Data were obtained from a prior larger study collecting EORTC QLQ-C30 norm data across 15 countries. Data were stratified by sex and age groups (18-39, 40-49, 50-59, 60-69 and > 70 years). Sex and age distribution were weighted according to population distribution statistics. Sex- and age-specific normative values were analysed separately, as were participants with versus those without health conditions. Multiple linear regression was used to estimate the association of each of the EORTC QLQ-C30 scales with the determinants age, sex, sex-by-age interaction term, and health condition. RESULTS: In total, 1,165 Spanish individuals participated in the study. Differences were found by sex and age. The largest sex-related differences were seen in fatigue, emotional functioning, and global QOL (Quality of Life), favouring men. The largest age differences were seen in emotional functioning, insomnia, and pain, with middle-aged groups having the worst scores. Those > 60 years old scored better than those < 60 years old on all scales except for physical functioning. Participants with no health conditions scored better in all QLQ-C30 domains. CONCLUSIONS: The present study highlights differences in HRQOL between specific sex/age strata and especially between people with and without a health condition in the general Spanish population. These factors must be considered when comparing general population HRQOL data with that of cancer patients.

A Modified Version of the Transactional Stress Concept According to Lazarus and Folkman Was Confirmed in a Psychosomatic Inpatient Sample.

BACKGROUND: Stress is a major risk factor for the impairment of psychological well-being. The present study aimed to evaluate the empirical evidence of the Transactional Stress Model proposed by Lazarus and Folkman in patients with psychosomatic health conditions. METHODS: A structural equation model was applied in two separate subsamples of inpatients from the Department of Psychosomatic Medicine (total n = 2,216) for consecutive model building (sample 1, n = 1,129) and confirmatory analyses (sample 2, n = 1,087) using self-reported health status information about perceived stress, personal resources, coping mechanisms, stress response, and psychological well-being. RESULTS: The initial model was created to reflect the theoretical assumptions by Lazarus and Folkman about their transactional stress concept. This model was modified until a sufficient model fit was reached (sample 1: CFI = 0.904, TLI = 0.898, RMSEA = 0.072 [0.071-0.074], SRMR = 0.061). The modified model was confirmed in a second sample (sample 2: CFI = 0.932, TLI = 0.928, RMSEA = 0.066 [0.065-0.068], SRMR = 0.052). Perceived external stressors and personal resources explained 91% of the variance of the stress response, which was closely related to symptoms of depression (63% variance explained). The attenuating effect of resources on stress response was higher (standardized ß = -0.73, p < 0.001) than the impact of perceived stressors on stress response (standardized ß = 0.34, p < 0.001). CONCLUSION: The empirical data largely confirmed the theoretical assumption of the Transactional Stress Model, which was first presented by Lazarus and Folkman, in patients with a wide range of psychosomatic conditions. However, data analyses were solely based on self-reported health status. Thus, proposed inner psychological mechanisms such as the appraisal process could not be included in this empirical validation. The operationalization and understanding of coping processes should be further improved.

Applying Item Response Theory to the OPD Structure Questionnaire: Identification of a Unidimensional Core Construct and Feasibility of Computer Adaptive Testing.

Recent developments in the dimensional assessment of personality functioning have made the implementation of latent measurement models increasingly attractive. In this study, we applied item response theory (IRT) to a well-established personality functioning instrument (the OPD Structure Questionnaire) to identify a unidimensional latent trait and to evaluate the feasibility of computer adaptive testing (CAT). We hypothesized that the use of IRT could reduce the test burden - compared to a fixed short form - while maintaining high precision over a wide range of the latent trait. The OPD-SQ was collected from 1235 patients in a psychosomatic clinic. IRT assumptions were fulfilled. A 9-factor model yielded sufficient fit and unidimensionality in exploratory factor analysis with bifactor rotation. Items were iteratively reduced, and a graded-response IRT model was fitted to the data. Simulations showed that a CAT with approximately 7 items was able to capture an OPD-SQ global severity score with an accuracy similar to that of a fixed 12-item short form. The final item bank and CAT yielded satisfactory content validity. Strong correlations with depression and anxiety replicated previous results on the OPD-SQ. We concluded that IRT applications could be useful to reduce the test burden of personality functioning instruments.

Normative data for the EORTC QLQ-C30 from the Austrian general population.

BACKGROUND: The European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 is a widely used cancer-specific questionnaire assessing 15 domains of health-related quality of life (HRQoL). Our aim was to facilitate the interpretation of scores on this questionnaire by providing Austrian normative data based on a general population sample. METHODS: The calculation of normative data was based on the EORTC QLQ-C30 data collected from an Austrian general population sample that was part of an international online panel study on the development of European normative data. Data reported herein were stratified and weighted by age and sex. Normative data were calculated for all 15 HRQoL domains of the EORTC QLQ-C30. For precise predictions of EORTC QLQ-C30 scores, a regression model based on sex, age and the presence of health conditions was built. RESULTS: The Austrian sample comprised 1002 Austrian participants (50.1% female, 51.4% when weighted by age and sex based on United Nation statistics). The mean age was 53.7 years (weighted: 47.7 years) and 53.6% (weighted: 47.4%) reported at least one health condition. Men reported better physical (Cohen's d = 0.17) and emotional (Cohen's d = 0.17) functioning as well as less fatigue (Cohen's d = 0.18) and insomnia (Cohen's d = 0.25) compared with women. Younger individuals (< 40 years) reported less dyspnea (Cohen's d = 0.61) and pain (Cohen's d = 0.51), whereas older individuals (≥60 years) reported better emotional functioning (Cohen's d = 0.55). CONCLUSIONS: We present Austrian normative data for the EORTC QLQ-C30. Differences by age and sex are mostly in line with the findings of other European normative studies. The Austrian population sample shows higher HRQoL and lower morbidity compared with other European countries. The normative data in this study will facilitate the interpretation of EORTC QLQ-C30 scores in oncological practice and research at a national and international level (including cross-cultural comparisons).

Updated EORTC QLQ-C30 general population norm data for Germany.

OBJECTIVE: The European Organisation for Research and Treatment of Cancer (EORTC) core questionnaire, QLQ-C30, is a frequently used patient-reported outcome (PRO) instrument to assess health-related quality of life of patients with cancer. To enhance the understanding and interpretation of PRO data, it is important to obtain norm data from the general population. This article presents updated general population norm data for the EORTC QLQ-C30 for Germany. METHODS: Data were obtained as part of a larger study collecting EORTC QLQ-C30 norm data across 15 countries via an online survey. After linear transformation of EORTC QLQ-C30 raw scores, data were weighted based on the United Nations' population distribution statistics. Data are presented by age and sex/age. RESULTS: A total of 1006 Germans responded to the survey. Across EORTC QLQ-C30 domains, different response patterns were observed, with men generally scoring better, that is, higher in most function scales and lower in most symptom scales/items than women. For age, mixed patterns were observed. While older respondents scored worse/lower in physical and role functioning, emotional functioning scores appeared to increase with increasing age. For the symptom scales/items, some symptoms were relatively stable across age groups, while others either increased or decreased with increasing age. CONCLUSIONS: This study presents updated EORTC QLQ-C30 general population norm data for Germany that can readily be used for comparative purposes with data obtained from patients with cancer.

Using subdomain-specific item sets affected PROMIS physical function scores differently in cardiology and rheumatology patients.

OBJECTIVES: The Patient-Reported Outcomes Measurement Information System (PROMIS) physical function (PF) item bank has been developed to standardize patient-reported PF across medical fields. However, evidence of scoring equivalence across cardiology and rheumatology patients is still missing. Therefore, this study aims to investigate both (1) the extent of disease-related differential item functioning (DIF) and (2) the impact of the disease group on using subdomain-specific item sets for generating PROMIS PF scores in cardiology and rheumatology patients. STUDY DESIGN AND SETTING: Ordinal regression was used to evaluate DIF between cardiology (n = 201) and rheumatology (n = 200) inpatients. To explore the disease-specific impact of PF subdomains on scoring, we compared scores derived from the full item bank with scores derived from subdomain-specific item sets for each disease group. RESULTS: DIF was detected in 18 items, predominately from the upper extremity subdomain. When upper extremity items were used, cardiology patients reached systematically higher scores than using the full item bank. Rheumatology patients scored substantially higher when mobility items were used. CONCLUSION: Applying the PROMIS PF metric to disease-specific item sets including items from differing subdomains may lead to biased comparisons of PF levels across disease groups. Disease-specific item parameters should be provided for items showing DIF, and subdomain-related content balancing is recommended for scoring the generic PROMIS PF construct.