Health-Related Quality of Life

Health-Related Quality of Life (HRQoL) 9999 patealthrelated ya QoL vs. HRQoL HRQoL and importance of measuring HRQoL Domains and measurement of health status Preference-based utility measures: EQ-5D, SF-6D Indigomethods Generic and disease-specific HRQoL measuresGorusedforutility Assessment of HRQoL measures calculation Patient-reported outcomes Rascati (Chapter 8) SE36synotoset utilitycalarat 1 QoL vs. HRQoL • Quality of Life (QoL) ―A broad concept that measures people’s overall perception of their well-being ―Includes both health-related and non-health-related (economic, political, cultural) QoL • Health-related quality of life (HRQoL) ―The part of a person’s overall QoL that represents the functional effect of an illness and its consequent therapy upon a patient as perceived by the patient • Both terms are often used interchangeably in health research 3 Importance of measuring HRQoL • HRQoL goes beyond a consideration of health that is only from the biomedical viewpoint ―The biomedical viewpoint of health is narrower and focuses on activities related to injury repair and reducing the impact/length of illness (mainly physical functioning) • Meanwhile, the HRQoL viewpoint is broader and encompasses all aspects that are important to a person’s health ―It includes a measure of the overall impact of diseases and their treatment, including areas such as: →physical functioning →psychological or mental functioning →social functioning 4 Domains of health status addressed by HRQoL 1. Physical functioning ―Activities of daily living (bathing, dressing, eating) ―Energy level ―Bodily pain 2. Psychological or mental functioning ―Anxiety ―Depression ―Nervousness ―Moodiness ―Life satisfaction ―Cognitive function 3. Social/Role functioning ―Social: ability to develop, maintain, and nurture social relationships ―Role: patient’s normal duties and responsibilities limited by health condition 6 How is health status (quality of life) measured? By using health instruments/measures (e.g., RS, SG, TTO, EQ-5D, SF-6D, and SF-36) 7 Health measures There are three broad categories of health measures: 1. Direct elicitation utility measures (e.g., RS, SG, TTO) 2. Indirect elicitation utility measures (e.g., EQ-5D, SF-6D) ―Also referred to as “preference-based measures” 3. HRQoL measures (e.g., SF-36) Upired from ―These can measure quality of life but numbers obtained from them are not used as “utility” scores for the calculation of QALY 8 Utility measures • Utility ―Values that individuals assign to different health states ―Range from 0 (dead) to 1 (perfect health) • Utility measures are classified as (i) direct elicitation utility measures or as (ii) indirect, preference-based utility measures • Examples of direct elicitation utility measures include: ―Rating scale (RS) ―Standard gamble (SG) ―Time-trade off (TTO) →Scores obtained using these methods can be used as a ‘utility’ score in economic evaluations such as CUA • Examples of indirect elicitation, preference-based utility measures include: ―EQ-5D ―SF-6D →Scores obtained using these methods can also be used as a ‘utility’ score in economic evaluations such as CUA 9 Indirect elicitation, preferencebased utility measures EQ-5D, SF-6D 10 Indirect, preference-based utility measures • Also called indirect elicitation utility measures • Advantages ―Less time-consuming and less resource-intensive compared to direct utility measures such as SG and TTO ―Unlike HRQoL measures, the utility scores can be used in economic evaluations • Utility scores range from 0 to 1 • Examples include: 1. The EuroQoL 5D (EQ-5D) 2. Short-Form 6D (SF-6D) 3. Health Utilities Index 3 (HUI3) 11 Preference-based utility measures EQ-5D MSUAP • There are two versions: ―EQ-5D-3L (three levels of responses) ―EQ-5D-5L (five levels of responses) • Five domains are measured: 1. 2. 3. 4. 5. Esan Mobility Self-care Usual activities (e.g. work, study, housework) Pain/discomfort Anxiety/depression • Average time to administer is 2 minutes • Developed in the United Kingdom • Scores obtained can be used as ‘utility’ scores in economic evaluations 12 EQ-5D-3L 13 EQ-5D-5L 14 Preference-based utility measures SF-6D • Short-Form 6D (SF-6D) ―Developed from the SF-36 survey • There are 6 domains of health measured: 1. 2. 3. 4. 5. 6. Physical functioning Role participation Social functioning Bodily pain Mental health Vitality x • Takes average of 8 minutes to complete • Developed in the United States • Scores obtained can be used as ‘utility’ score in economic evaluations 15 Preference-based utility measures SF-6D The SF-6D is copyrighted and is available on a license basis https://www.shef.ac.uk/scharr/sections/heds/mvh/sf-6d 16 HRQoL Measures/Instruments General health measures (e.g., SF-36) Disease-specific measures (e.g., AIMS) 17 HRQoL measures • Also called non-utility measures, or non-preference-based measures • Scores from HRQoL instruments are NOT recommended to be used as utility scores in economic evaluations • There are two broad categories of HRQoL measure/instrument/tool: 1. General health status (generic measures) 2. Disease-specific measures 18 Generic vs. disease-specific HRQoL measures 1. Generic measures are broadly applicable to all diseases ―They measure the general well-being of the patient whereas diseasespecific measures are more relevant for assessing specific diseases and populations 2. Disease-specific measures are more responsive to changes in health whereas generic measures may not be as responsive to changes in health ―If improvement in health status occurs, disease-specific measures does a better job at measuring it 19 Examples of generic HRQoL measures Eton 1. Medical Outcome Study Short Form-36 (SF-36) 2. Quality of Well-Being (QWB) Scale 3. Dartmouth COOP Functional Assessment Chart 20 Generic measures 1. Medical Outcome Study Short Form-36 (SF-36) • 36 items (or questions) • 8 domains of health are measured 1. 2. 3. 4. 5. 6. 7. 8. Bodily pain General health Mental health Physical functioning x Role-emotional Role-physical Social functioning Vitality 21 SF-36 22 SF-36 23 SF-36 24 SF-36 25 SF-36 26 SF-36 27 Generic measures 2. Quality of Well-Being (QWB) Scale • 71 items • 4 domains of health are measured 1. 2. 3. 4. Mobility Physical activities Social activities Symptom/problem complexes • 10-15 minutes to administer Source: http://www.rehabmeasures.org/Lists/RehabMeasures/PrintView.aspx?ID=1037 28 Generic measures 3. Dartmouth COOP Functional Assessment Chart • • Incorporates pictures/charts in addition to word descriptions 9 domains of health are measured 1. 2. 3. 4. 5. 6. 7. 8. 9. Physical Fitness Feelings Daily Activities Social Activities Pain Change in Health Overall Health Social Support Quality of Life Source: http://www.fvfiles.com/521475.pdf 29 Dartmouth COOP Functional Assessment Chart Physical fitness domain 30 Disease-specific HRQoL measures e.g., PSDI, BPH, AIMS, FACT 31 Disease-specific HRQoL measures • Needed when generic tools cannot provide adequate information about a specific disease • Examples 1. Physical Symptoms Distress Index (PSDI) →Hypertension 2. BPH Impact Index →Benign prostatic hyperplasia 3. Living with Asthma Questionnaire →Asthma 4. Diabetes-Specific QoL Instrument (DQOL) →Diabetes 5. Arthritis Impact Measure Scale (AIMS) →Arthritis 6. Functional Assessment of Cancer Therapy (FACT) →Cancer 32 Modes of Administering HRQoL Instruments Face-to-face Telephone Self-administered Surrogate 33 Eton Modes of administration of HRQoL instrumentsselectanthat 1 apply • There are four main ways by which HRQoL instruments can be administered: 1. Face-to-face interviewer-administered ― Resource intensive – requires training of interviewers ― Reduced willingness of responder to acknowledge problems 2. Telephone-administered ― Few, if any missing items/questions ― Less resource-intensive than face-to-face 3. Self-administered ― Minimal resources required (paper and web-based surveys) ― Low response rate, missing items, misunderstanding of question 4. Surrogate responders ― Needed for children, cognitively impaired patients, and those with language barrier ― Perception of health of surrogate may differ from those of patient 34 How do we know if HRQoL instruments are measuring what they are supposed to be measuring? Then assess their:  Reliability  Validity  Responsiveness 35 Assessment of HRQoL measures • HRQoL measures are subjective (based on patient’s opinions) in contrast to objective data such as BP measurements, x-ray, urinalysis, etc. ―Therefore, it is important to know if the HRQoL measures are doing what they are supposed to be doing →Are they reliable? →Are they valid? →Are they responsive to changes in health status? 36 Assessment of HRQoL measures/instruments • Three psychometric properties of HRQoL measures that are commonly assessed include: 1. Reliability (or consistency) 2. Validity 3. Responsiveness 37 Psychometric properties of HRQoL measures Reliability Test-retest Internal consistency Inter-rater reliability 38 Reliability Great • Reliability refers to the consistency of the instrument ―Does it produce the same score on multiple administration? →Same score by same person at different times? →Same score on same person by different raters? • Three types of reliability assessments are: 1. Test-retest 2. Inter-rater reliability 3. Internal consistency 39 Reliability Test-retest reliability • Does the instrument give the same result (score) for the same person at two different times when the health status of the person has not changed? ―Are the scores consistent? →If scores are consistent, this shows that the HRQoL instrument has good testretest reliability 40 Reliability Inter-rater reliability • This calculates whether there is agreement (or correlation) in the scores obtained by two assessors (or raters) who assessed the health status of the same patient using the same HRQoL instrument ―For example, health assessment scores completed by mother and teacher for a boy with ADHD should correlate/agree →If there is correlation, this shows that the HRQoL instrument has good interrater reliability 41 Reliability Internal consistency • This measures if responses (answers) to two or more questions assessing the same domain are correlated (or agree with each other) ―If two items (or questions) are measuring the same aspect of health (e.g., vitality), the answers elicited by the respondent should be similar →If similar, this shows that the HRQoL instrument has good internal consistency reliability 42 Reliability Example - internal consistency 43 Assessment of HRQoL measures • Three psychometric properties of HRQoL measure that are commonly assessed include: 1. Reliability (or consistency) 2. Validity 3. Responsiveness 44 Psychometric properties of HRQoL measures Validity Content or face validity Criterion or predictive validity Construct validity (convergent, discriminant) 45 Reliability vs. validity Not consistently hitting any particular spot, Consistently hits a particular spot, and all wrong spots but the wrong spot Consistently hits a particular spot, and the right spot 46 Validity • It is possible for an instrument to be reliable (consistent), yet not valid (imprecise) ―However, for an instrument to be valid, it first needs to be reliable ―All HRQoL instruments needs to be both reliable and valid • Validity assesses if the scores obtained from HRQoL measures truly represent the underlying construct (domain) of the HRQoL ―Is the instrument measuring what it is supposed to be measuring? • Validity is much more difficult to assess than reliability 47 Types of validity assessment • There are three common types of validity assessment: 1. Content validity (or face validity) ― Upon surface inspection, does the content of the instrument seem relevant to what is being measured? → → For example, an instrument that was supposed to measure HRQoL related to asthma should contain asthma-related questions or domains important to an asthma patient If it does, the instrument is said to have good content/face validity 2. Criterion validity (or predictive validity) ― Does the instrument have predictive ability? → → For example, does high HRQoL score (indicating good health) predict, or have a positive correlation with low use of medical service (an external criterion)? If it does, the instrument is said to have good predictive validity 48 Types of validity assessment 3. Construct validity ― Constructs validity relates to the health domains measured by the instrument ― There are two main types of construct validity: 1. Convergent validity 2. Discriminant validity 49 Construct validity Convergent validity (different instrument, same construct) • Does different HRQoL instrument (e.g., different generic and/or disease-specific) measuring the same construct or domain (e.g., mental health) provide similar results? ― For example, scores obtained from the mental health domain of a generic HRQoL instrument (e.g., SF-36) should correlate with scores obtained from a disease-specific HRQoL instrument developed to assess mental health 50 Construct validity Discriminant validity • Can the different constructs/domains within the same HRQoL instrument be differentiated from each other? ―For example, the scores obtained for the physical functioning domain of the SF-36 instrument will not necessarily be expected to be correlated with the scores obtained for the mental functioning domain of the SF-36 ―If this property of non-correlation of vastly different domains is true, the instrument is said to exhibit good discriminatory validity property 51 Psychometric properties of HRQoL measures Responsiveness Can the instrument detect changes in health status over time? 52 Responsiveness • Responsiveness is the ability of an instrument to: 1. Detect changes in a patient’s health over time when their health changes →For example, score of health status measured at baseline (before intervention/worse health) should differ from scores obtained after an intervention (better health) 2. Show numerical differences in scores between patients who have different health status →For example, scores obtained from instruments should be indicative of patients’ health status • Sometimes, higher scores mean better health 53 Patient-Reported Outcomes (PROs) Measures 54 Patient-reported outcomes (PROs) • The FDA defines a PRO as “any report of the status of a patient’s health condition that comes directly from the patient, without interpretation of the patient’s response by a clinician or anyone else.” 55 Differences between PROs and HRQoL instruments • PROs utilizes HRQoL instruments (e.g., SF-36), direct elicitation utility measures (e.g., RS, SG, TTO), and indirect elicitation utility measures (e.g., EQ-5D, SF-6D) to assess health outcomes ONLY from the patient’s perspective • Whereas, HRQoL instruments can be used to report health outcomes from perspectives other than that of the patient (e.g., from physician, nurses, etc.) 56 Value and purpose of PROs • PROs allows outcomes that patients care about to be assessed, beyond only survival or mortality • PROs incorporate patients’ perspectives of treatments, both in terms of patients’ actual experiences and their judgments about the value of care • In clinical trials, a PRO instrument can be used to measure the effect of a medical intervention on one or more concepts (e.g., mental, physical, or social functioning) ―PROs can be used to support a claim in medical product labeling if the claim is consistent with the instrument’s documented measurement capability 57 Value and purpose of PROs • In prostate cancer therapy, for example, there is no conclusive evidence regarding the relative survival advantages of the leading therapeutic options such as surgery and radiation therapy ―However, PROs collected from patients can help providers and patients identify interventions with the greatest benefits and minimal harms ―The following HRQoL outcomes can be measured: →symptoms and side effects related to urinary, bowel, and sexual function, and overall satisfaction 58 Summary 1. Major domains of health status include physical, mental, social, spiritual, economic, and general well-being 2. Direct elicitation utility measures include RS, SG, TTO 3. Indirect elicitation or preference-based utility measures include EQ-5D and SF-6D 4. Scores from direct elicitation and indirect elicitation utility measures can be used as ‘utility’ scores in economic evaluation 59 Summary 5. Scores from HRQoL measures (generic or disease-specific, e.g., SF-36) are NOT recommended to be used as ‘utility’ scores in economic evaluation 6. A good example of a generic HRQoL instrument is SF-36 7. The SF-36 instrument has 36 items/questions and assesses health in 8 domains 8. The three psychometric properties that a good HRQoL instruments should have are reliability, validity, and responsiveness 60 Summary 9. Reliability answers the question: Does the instrument produce the same score on multiple administration? 10.Validity answers the question: Is the instrument measuring what it is supposed to be measuring? 11.Responsiveness answers the question: Can the instrument detect changes in health status over time? 12.PRO instruments utilizes HRQoL instruments and assesses health outcomes ONLY from the patients’ perspective 61