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Workshop #1 9:00 am - 12:00 pm Level: Basic MEASURING HEALTH STATE PREFERENCES OF THE GENERAL POPULATION IN A GROUP SETTING Sarah Gorber, MA and Julie Bernier, MSc The appropriate and efficient use of limited health resources is a perennial issue among health-care providers, policy-makers, and society at large. Information, and ideally, evidence, must form the basis upon which decisions are made. In the past, the impact (burden) of non-fatal outcomes of disease and injury on population health tended not to receive appropriate policy attention. However, healthy living and quality of life are now increasingly recognised as important policy goals, and research on the burden of disease helps to quantify the impact of non-fatal diseases. This workshop focuses on the main measures for eliciting health state preferences from the general population within the context of a Burden of Disease Study, which provide a means for considering the significance of non-fatal outcomes. This requires eliciting a numerical value or preference score reflecting the populations relative preference for each of a series of diseases or health states. Two tools for measuring preference scores in group settings will be discussed. In order to gain a greater understanding of the advantages and disadvantages of each of the methods, participants will then be taken through a series of exercises that simulate the panels used for eliciting the health state preference scores. Participants will begin by ranking health states using a Visual Analog Scale (VAS). The VAS is used as a teaching tool to familiarise participants with the health state descriptions and to answer any questions that may arise. A facilitator will then help the group to measure preference scores using the Standard Gamble, which provides utility measures. Results of testing and collection in the Canadian study will then be discussed and a sub-set of the Canadian preference scores will be presented. Methods for calculating the Canadian Summary Measure of Population Health (i.e., Health Adjusted Life Years Lost, HALY) for over 500 health states will be presented. Workshop #2 9:00 am - 12:00 pm Level: Basic HEALTH RELATED QUALITY OF LIFE IN CHILDREN AND YOUTH Ulrike Ravens Sieberer, PhD, Jeanet Bruil, PhD, and Monika Bullinger, PhD While quality of life research in adults has progressed substantially over the past 15 years, health-related quality of life of children has only recently been addressed. QOL research in children is important because children can be confronted with disease and treatment as patients. Epidemiological research has so far neglected living conditions that might be detrimental to the health-related quality of life of children; exceptions are a few studies published in the area of public health and clinical psychology. Reflections on how to assess quality of life of children also bear on the focus of such assessment. One dimension concerns the type of assessment intended, i.e. the use of questionnaires or interviews, of computer assisted programs, or of observational methods. A second dimension refers to who assesses the quality of life of children. In general, expert ratings, that is external observation of children's quality of life, have been favoured; however, the essence of quality of life assessment is the self rating method. The question of whether and at which age children are able to report on their feelings has been intensively discussed, and principally deemed realisable under the condition that an instrument corresponding to the child's abilities can be chosen. This workshop reviews the state of the art of quality of life assessment in children/adolescents as it relates to the underlying concepts the instruments available, and application in research and practice. Presentation will include a comprehensive literature review, demonstration of instruments as well as their computer-assisted versions, and a thorough evaluation of the evidence of their use in clinical studies and patient care. Generic as well as disease-specific measures (e.g. asthma, diabetes, epilepsy, rheumatoid arthritis) will be focussed on. The material presented will profit from results of recent discussions within an international expert group, collaborating in two large EC funded projects on "Quality of Life of Children with Disabilities (DISABKIDS)" and "Assessing Health Related Quality of Life in Representative Samples of European Children (KIDSCREEN)." Workshop #3 9:00 am - 12:00 pm Level: Basic PSYCHOMETRICS: PROCESSES AND APPLICATIONS Valerie Williams, PhD, Lori McLeod, PhD, and Sheri Fehnel, PhD This workshop is intended to be an intermediate introduction to psychometrics and its value in outcomes research. Specific issues and applications using psychometrics to evaluate the utility of patient-reported outcomes will be discussed. Our goal is to provide participants with a basic understanding of commonly used psychometric techniques, including guidance for interpreting results from software tools. Three psychometric processes will be covered: instrument development, validation, and the creation of short forms. The first topic will be a basic overview, identifying the necessary components of a development plan. An example plan will be provided, and the purpose and general principles behind each step, including conducting focus groups and individual interviews, will be described. The second topic will be the task of validating a draft instrument. The presenters will lead a discussion surrounding the process of validation prior to including an instrument in a clinical trial as a primary outcome measure. Together, the workshop participants will create a list of issues and concerns relevant to a validation design and its implementation. Example validation plans will illustrate differences among various research goals and results from studies will demonstrate the application of various quantitative techniques. Specifically, exploratory factor analysis and structural equations modeling, as well as different approaches for quantifying reliability and responsiveness, will be explained. In addition, the use of Item Response Theory for item analysis and evaluation will discussed. Finally, the use of data from a validation study to inform item reduction will be presented. For this application, the trade-offs related to score precision and respondent burden will be addressed, with special attention to the use and advantages of computerized adaptive testing. Throughout the workshop, the presenters will entertain questions from the participants about problems and analytic methods related to the development of questionnaires to measure patient-reported outcomes. Workshop #4 9:00 am - 12:00 pm Level: Basic COGNITIVE ASPECTS OF SURVEY METHODOLOGY AND QUALITY OF LIFE ASSESSMENT Elaine McColl, MSc The term "Cognitive Aspects of Survey Methodology" (CASM) is applied to the interdisciplinary effort to investigate and understand the cognitive processes employed by respondents in reading, comprehending and interpreting questions, and in formulating and providing answers to those questions. Tourangeau and colleagues have proposed a four-stage model of the question response process: comprehension; retrieval; judgement; response. At each stage, threats to the validity and reliability of responses may arise. The model is clearly applicable to questions and instruments measuring health status and quality of life. Quality of life assessments typically require respondents to: understand complex, abstract questions; retrieve information from long-term memory; aggregate that information; apply frequency judgements, magnitude estimation and decision heuristics in selecting which response category to endorse. To date, CASM techniques have most usually been applied in the development, pre-testing and refinement of questions and instruments. However, there is growing interest in applying these techniques to existing instruments to investigate whether the cognitive processes vary across cultures or with respect to other respondent characteristics. In this workshop, the desirability of applying CASM techniques in quality of life assessment will be outlined. Key CASM techniques, in particular the technique of cognitive interviewing, will be described. Participants will have the opportunity to apply a draft cognitive interviewing protocol developed by the International Study Group on Cognitive Aspects of Quality of Life Research. Workshop #5 9:00 am - 12:00 pm Level: Basic INTERPRETATION OF HEALTH-RELATED QUALITY OF LIFE (HRQOL)SCORES David Osoba, MD, FRCPC and Madeliene King, PhD This workshop will provide an introduction to the interpretation and use of HRQOL measures and results in clinical research and practice. Co-presented by a clinician and a statistician, it will cover a broad range of issues in a very practical way with an emphasis on clinical contexts, issues and relevance. The clinician's concern is with finding clinical meaning in HRQOL results and translating group-based results into potential benefit for the individual. Good empirical evidence about the effects of treatment on patient HRQOL can help patients and health care professionals make more informed decisions about therapy and medical management. Yet interpreting the clinical significance of effects observed on HRQOL scales is problematic because there are so many HRQOL scales and their units of measurement are unfamiliar. This workshop will provide an overview of methods of interpreting HRQOL results that will be helpful to the clinician. It will draw heavily on experience from clinical trials in a variety of clinical settings, ranging from primary prevention, secondary prevention, curative treatment, and palliative therapy through to palliative care. It will provide insights into the interpretation of differences in mean scores between groups, changes in mean scores within groups over time, and the scores of individual patients monitored over time. Statistical approaches to interpreting HRQOL data will be overviewed. The distinction between statistical significance and clinical importance will be explained and illustrated, and sample size and power will be discussed. Statistical concepts will be explained in practical terms and illustrated with clinical examples. At the completion of the workshop, the participant should be familiar enough with these approaches to feel comfortable with interpreting the data presented in HRQOL literature and applying it to clinical situations. Workshop #6 9:00 am - 12:00 pm Level: Intermediate Strategies for Multiple Endpoints in Longitudinal Studies of Health-related Quality of Life Diane Fairclough, DrPH Multiplicity of potential endpoints arises in longitudinal studies of HRQOL from the multiple domains used to assess HRQoL and the repeated measures that occur in a longitudinal study. Testing a large number of hypotheses creates problems in the interpretation of the results and inflates the Type I error rate. However, over control of the Type I error rate has the potential to severely decrease the power of the study to detect meaningful differences (Type II errors). In this workshop, we will start by examining the advantages and disadvantages of a range of strategies including 1) limiting confirmatory tests, 2) summary measures/statistics across time, 3) creation of indices from the component subscales, and 4) multiple comparisons procedures. Next, we will split into small working groups with the task of developing a strategy for a hypothetical trial. Finally, the proposals will be presented to the entire group and discussed. After completing this workshop, participants will be able to:
Workshop #7 1:00 pm - 4:00 pm Level: Basic INTRODUCTION TO ITEM RESPONSE THEORY AND ITS APPLICATIONS Chih-Hung Chang, PhD, and Bryce Reeve, PhD Although item response theory (IRT) models have been developed and widely used in educational and psychological testing for many decades, their use in health-related quality of life (HRQOL) measurement has just flourished. Theoretically-sound IRT models coupled with available software packages make it possible for researchers and practitioners to develop and refine HRQOL assessment instruments for use in research and clinical trials. This workshop will provide an overview of IRT models and how they can be appropriately applied to HRQOL assessment. Specifically, the following topics will be discussed: 1) dichtomous vs. polytomous models; 2) unidimensional vs. multidimensional models; 3) instrument/scale construction; 4) exploratory vs. confirmatory item-level factor analysis; 5) instrument equating; 6) differential item functioning; 7) item banking and computerized adaptive testing; and 8) software availability and capacity. Examples using empirical data and annotated computer outputs will be provided and discussed. Guidelines to the selection of models and software will also be provided. Workshop #8 1:00 pm - 4:00 pm Level: Intermediate Technical Aspects of Questionnaire Development Hanne Thorsen, PhD, and Stephen McKenna, PhD In recent years, there have been major advances in methods for gathering questionnaire content designed to assess some form of subjective health status, for example, the use of face-to-face interviews with representatives of patient groups and focus groups. However, there has been a decline in the amount of attention paid to the more detailed aspects of questionnaire design such as the instructions to respondents, the format, the layout and wording of items and interpretation of items in different groups. Also, the choice of user friendly response options seems to be a topic which is seldom discussed. All of these can have profound effects on responses and missing data. It is suggested that too much emphasis has been placed upon quantitative methods for the establishment of validity and not enough on qualitative work with individuals. The emphasis of the workshop will be on ensuring "respondent friendliness" of questionnaires, an issue that is often neglected. The participants will be asked to complete several pre-existing questionnaires. Workshop #9 1:00 pm -4:00 pm Level: Intermediate TEXT ANALYSIS AS APPLIED TO QUALITY OF LIFE DATA Sarah Groom, PhD and Ivan Barofsky, PhD The purpose of this workshop is to demonstrate available text analytic models and to give participants the opportunity to apply one of these methods to quality of life data. Participants are encourage to bring laptop computors, although demonstration computors will be available. Computerized text analysis can be used on any electronic samples of natural language that contain at least 60-100 words. Samples can be transciptions of conversations such as interviews or doctor-patient communications. Responses to open-ended survey questions are also appropriate. Text analytic procedures aim to quantify how people talk (i.e., lingusitic style) and what people talk about (i.e., content). By analyzing examples of quality of life data , we will show how these techniques can provide clues about the way that a respondent views their quality of life, offering an alternative to judgment-based methods (e.g., content analysis). This information can be used to compare groups of respondents or follow changes in a respondent's quality of life over time. The workshop will cover issues imvolved in applying text analysis, from data preparation to the implications of comparing groups who do not even share the same language. Workshop #10 1:00 pm - 4:00 pm Level: Advnaced EVALUATING CHANGE IN HEALTH-RELATED QUALITY OF LIFE MEASURES Kathleen Wyrwich, PhD, and Paul Krabbe, PhD Although numerous measures have been developed for the evaluation of health related quality of life (HRQoL), strategies for identifying meaningful intra-individual and group change in these measures have not kept pace with instrument development. As a result, clinical trial researchers, quality assurance assessment teams, practicing clinicians, and patients are without established standards to evaluate change in HRQoL measures. This course will review, critique and compare the methods that have been applied to establish intra-individual and group HRQoL change standards, which include anchor- and distribution-based (statistical) techniques. Practical approaches to improving and advancing HRQoL change evaluations that enhance the interpretation of intra-individual and group change, as well as a review of controversies that have developed will be provided. In addition, the course will explore future qualitative and quantitative challenges in this area of HRQoL research. Workshop Outline:
The workshop will be divided between 70% lecture, 15% class exercises, and 15% discussion and answer periods. Participants are strongly encouraged to bring a hand calculator. Topics: This workshop focuses on the theoretical/methodological topic of interpretation, with disease-specific applications to topic of chronic disease patients in the specific research setting of health services research Workshop #11 1:00 pm - 4:00 pm Level: Advanced INTERPRETING UTILITY (PREFERENCE-BASED) MEASURES OF HEALTH-RELATED QUALITY OF LIFE David Feeny, PhD, and George Torrance, PhD The Workshop will be at an Advanced level, focusing on the interpretation of utility scores including direct and multi-attribute (indirect) approaches. The direct approaches will include the visual analogue scale (Feeling Thermometer), time tradeoff, and standard gamble. Major multi-attribute utility measures discussed will include the EuroQol EQ-5D, Health Utilities Index (HUI), Short-Form 6D, and Quality of Well-Being Scale (QWB). In addition, recent work on disease-specific utility instruments will be presented. The Workshop will include hands on experience in the direct assessment of utility scores and in completing questionnaires from several systems and analyzing and interpreting the results. The interpretation of scores will be considered in the context of comparing groups at a point in time as well as comparing within-person change over time. Applications will be drawn from diverse settings including osteoarthritis of the knee, multiple sclerosis, total hip arthroplasty, and acute lymphoblastic leukemia. Evidence on clinically important differences will be discussed. Attendees should at a minimum have a basic knowledge of the conceptual foundations and practical approaches of the utility approach to assessing health-related quality of life. Workshop #12 1:00 pm - 4:00 pm Level: Advanced COMPARISONS OF METHODS FOR EVALUATING THE PSYCHOMETRIC EQUIVALENCE OF QUESTIONNAIRES AFTER TRANSLATIONS: FACTORIAL ANALYSIS, MULTITRAIT ANALYSIS AND IRT Christina de la Loge, MS, and Patrick Marquis, MD, MBA The most important question researchers faces after a careful and appropriate translation process aiming at conceptual equivalence from a qualitative point of view, is the evaluation of the measurement characteristics of the translated versions, particularly equivalence of the structure (and therefore of the constructs) with the original language version. Before pooling international data, researchers should understand whether the translation process has introduced minor disturbances with no practical implications, or misfits but without compromising the validity of the overall measure, or major degradations of the questionnaire structure, incompatible with the original version. The most popular methods will be reviewed and discussed based on concrete examples: exploratory factorial analysis and multitrait analysis, confirmatory factorial analysis and its extension to structural modeling, and finally the IRT. Participants will be first presented with background on the principle and the basis for interpreting each method. Then real data will be presented and the findings discussed. Finally the advantages and the issues with each method will be discussed. Exploratory factorial analysis and the multitrait analysis provide valuable information on factor loading or item-test correlation but don t provide a formal test for the equivalence of structures across languages. Confirmatory factorial analysis and more complex structural modeling allow the comparison of structures through chi2 and fit indexes. They also provide information on problematic items thanks to the modification indexes. The IRT provide the most detailed information for each item in the latent variable measured by the item set (item ranking, fit statistics, structure of residuals). Item differential functioning allow a direct comparison of the item performance in different languages. But IRT requires the unidimensionality, making the comparison of multidimensional construct difficult. Issues related to patient profiles and sample size will be discussed as well. Workshop #13 1:00 pm - 4:00 pm Level: Advanced OBTAINING HEALTH STATE UTLITY VALUES FROM QUALITY OF LIFE MEASURES John Brazier, PhD This workshop is concerned with the use of measures of health related quality of life (HRQoL) in economic evaluation, including their use in deriving the health state utility values as required to calculate Quality Adjusted Quality Life Years (QALYs). The workshop is designed to provide a practical introduction to the problems and issues around the topic. It assumes a basic knowledge HRQoL measurement and preference-elicitation techniques (such as standard gamble and time trade-off). Students unfamiliar with the latter are recommended attending the ISOQOL workshop introducing Health State Preference/Utility Assessment. There will be four brief presentations:
Organisation of workshop: 50% will be composed of these four brief presentations on each of these topics, 35% on a small group exercise addressing the appropriateness of different methods for obtaining health state utility values in different contexts and 15% Q&A (though questions are welcomed throughout). |
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