Patsi Sinnott, PT, PhD, MPH HERC Economics Course April 7, 2010 Introduction to Effectiveness, Patient Preferences and Utilities

Overview Brief review of cost-effectiveness analysis (CEA) and cost utility analysis (CUA) Quality of life and health-related quality of life Review of preference/utility measurement Health Economics Resource Center

Overview (con’t) Review of the most frequently used preference measurement systems Preference measurement in clinical trials Guidelines on selecting measures 3

HERC SharePoint site HERC CyberCourse Discussion board on the HERC SharePoint site on the VA intranet. VA staff may request the URL of the HERC discussion board by writing to 4

Poll 1 Mobility –I have no problems walking about –I have some problems walking about –I am confined to bed Health Economics Resource Center

Poll 2 Self-Care –I have no problems with self-care –I have some problems with self-care –I am unable to wash or dress myself Health Economics Resource Center

Poll 3 Usual activities (e.g. work, study, housework, family or leisure activities) –I have no problems performing my usual activities –I have some problems performing my usual activities –I am unable to perform my usual activities Health Economics Resource Center

Poll 4 Pain/discomfort –I have no pain or discomfort –I have moderate pain or discomfort –I have extreme pain or discomfort Health Economics Resource Center

Poll 5 Anxiety/Depression –I am not anxious or depressed –I am moderately anxious or depressed –I am extremely anxious or depressed Health Economics Resource Center

CEA and CUA review CEA compares the costs and effectiveness of two (or more) interventions; –The effectiveness is defined by the health benefit or outcome achieved with the intervention. Health Economics Resource Center

CEA and CUA review All outcomes are defined using natural units, –Cost per avoided infection or hospitalization –Cost per day “free of anginal pain” –Cost per gain in Life Year (LY). 11

CEA and CUA review CEA and CUA require all outcomes be quantified in a single scale; –A day in hospital or an infection avoided vs. –A day “free of angina pain” –A day of “improved quality of life”. Health Economics Resource Center

Defining Quality of Life Surveys and questionnaires Domains of various aspects of life Each combination of answers defines a composite “state” or quality of life “status” for that individual Health Economics Resource Center

Defining quality of life Quality of life: broad concept, includes all aspects of life; where and how one lives and plays; family circumstances; finances; housing and job satisfaction. Health Economics Resource Center

Defining quality of life Health-related quality of life*: narrower concept, that only includes aspects of life dominated or significantly influenced by mental or physical well-being; Health Economics Resource Center * From Ware, et al., SF-36 Health Survey Manual

Defining quality of life Purpose of evaluation will determine the instrument –Quality of life measurement tool will define the broad concept of quality of life –Health-related quality of life (HRQoL) measurement tool will define an individual’s “health state” or “health status” Health Economics Resource Center

Defining health-related quality of life Health status surveys/instruments – Survey of patient perspectives about their own function, well-being and other important health outcomes. Health status measures describe the health state of an individual, for a specific period, or at a particular time, along various attributes of health. Health Economics Resource Center

Defining health-related quality of life HRQoL instruments are used to measure –Baseline health status –Comparative health status –Effectiveness/outcomes of clinical intervention Health Economics Resource Center

Instruments to measure HRQoL Generic instruments: –SF-36: 8 dimensions of health, including physical functioning, bodily pain, social functioning and mental health. Health Economics Resource Center

Whiteboard 1 What generic HRQoL instruments have you used? Health Economics Resource Center

Instruments to measure HRQoL Disease-specific measures: –Asthma Quality of Life Questionnaire (AQLQ) –American Urological Association’s Urinary Bother Scale –Oswestry Low Back Pain Questionnaire Health Economics Resource Center

Whiteboard 2 What disease-specific instruments have you used (for a study of what medical conditions?) Health Economics Resource Center

CEA/CUA CEA compares the costs and effectiveness of two (or more) interventions Health Economics Resource Center

CEA/CUA The effectiveness is defined by the health benefit or outcome achieved with the intervention This effectiveness is defined by a summary measure that combines: –Quantity of life, and –Quality of life, –Weighted by the preference for that quality of life Health Economics Resource Center

Whiteboard 3 What components of the subjects’ health status will you need to measure in a CEA? Health Economics Resource Center

Whiteboard summary Health care interventions have impact in many dimensions of life, Those impacts may be more or less desirable. Health Economics Resource Center

Whiteboard Summary At issue is how to quantify many attributes of outcome into a single measurement scale, which includes a valuation on the outcomes. This valuation is defined as preference 27

CEA/CUA The summary measure of health benefit or outcome in CEA is the QALY –Includes both quality and quantity of life; –adjusted for the desirability of, or preference for the benefit achieved. Health Economics Resource Center

The Quality Adjusted Life Year (QALY) QALYs describe years of survival, adjusted for quality of life: –0 = death –1 = perfect health Health Economics Resource Center

The QALY QALYs allow trade-off between length of life with quality of life: –1 QALY = 1 year in perfect health –1 QALY = 2 years with utility of

Quantifying the QALY or outcome Requires: –Description or estimation of the health states expected to be experienced by patients with the condition –Estimation of the duration of each health state –Assessment of patient or community preferences for each health state Health Economics Resource Center

Assessment of patient or community preferences for each health state Only health status measures, with preferences/utilities assessed, can be used in economic analysis; Only a few health status measures (generic or specific) have preferences/utilities measured. In this talk, per Gold, et al recommendations, preferences = utilities Health Economics Resource Center

Deriving preferences or utilities for health states Basic methodology: –Surveys of patients experiencing the condition or health state of interest; or –Surveys of a community sample. In both cases, individuals provide a personal reflection on the relative value of different health states experienced or described. Health Economics Resource Center

Deriving preferences or utilities Two methods to derive preferences: –Direct: –Indirect: Health Economics Resource Center

Sample health state description You are able to see, hear and speak normally You require the help of another person to walk or get around; and require mechanical equipment as well. You are occasionally angry, irritable, anxious and depressed. You are able to learn and remember normally. You are able to eat, bathe, dress and use the toilet normally. You are free of pain and discomfort. Health Economics Resource Center

Methods to assess preferences Direct method –Individuals asked to choose (declare preferences) between their current health state and alternative health status scenarios –Individuals make these choices based on their own comprehensive health state (or the composite described to them). Health Economics Resource Center

Methods to assess preferences for health states Direct Methods –Standard Gamble (SG) –Time Tradeoff (TTO) Health Economics Resource Center

Direct: Standard Gamble (SG) Live rest of life in current health state; or “take a pill (with risks) to be restored to perfect health” Scale represents risk of death respondent is willing to bear in order to be restored to full health. Health Economics Resource Center

Direct: Time Tradeoff (TTO) Health Economics Resource Center How much reduction in total life willing to give up in order to live in perfect health

How to get the SG & TTO The SG and TTO have are usually administered through interactive computer programs such as –U-Titer (Summer, Nease et al., 1991) –U-Maker (Sonnenberg FA, 1993) –iMPACT I and II(Lenert, Sturley, et al., 2002), –ProSPEC (Bayoumi) –FLAIR1, FLAIR2, (Goldstein et al.1993) Health Economics Resource Center

Methods to assess preferences Indirect method –Individuals asked to rate preferences for separate domains of health states  Physical function  Social functioning  Mental health etc. –Scores are aggregated to create a composite preference or utility weight for a health state Health Economics Resource Center

Sample Questions (EQ-5D) Which statements best describe your own state of health today? –Mobility:  1. No problems walking about  2. Some problems walking about  3. I am confined to bed Health Economics Resource Center

Sample Questions (EQ-5D) Which statements best describe your own state of health today? –Pain/discomfort  No pain or discomfort  Moderate pain or discomfort  Extreme pain or discomfort Health Economics Resource Center

The aggregate health state description You are able to see, hear and speak normally You require the help of another person to walk or get around; and require mechanical equipment as well. You are occasionally angry, irritable, anxious and depressed. You are able to learn and remember normally. You are able to eat, bathe, dress and use the toilet normally. You are free of pain and discomfort. Health Economics Resource Center

Indirect preference measurement systems Individuals respond to questions about the separate attributes of a health state, and a summary score or utility weight is calculated 45

Indirect preference measurement systems Health utility measures vary in: –Dimensions or attributes included; –The size and nationality of the sample population used to establish the weights; –Health states defined by the survey; and –How the summary score is calculated, etc. 46

Methods to assess preferences for health states Indirect Measures –Health Utility Index (HUI) –EuroQol (EQ-5D) –Quality of Well-Being Scale (QWB) –SF-6D Health Economics Resource Center

Indirect measures: Health Utility Index (HUI) 41 questions (many items can be skipped) –can derive both HUI Mark 2 and HUI Mark 3 health utility scores. 8 domains of health and 972,000 health states –vision, hearing, speech, ambulation, dexterity, emotion, cognition, and pain Basis of domain weights: –Canadian community sample rated hypothetical health states –Utility theory Health Economics Resource Center

How to get the HUI HUI is copyrighted and can be obtained for a fee (~$3,000) from Health Utilities Inc ( For an overview of the HUI see Horsman, Furlong, Feeny, and Torrance (2003) Health Economics Resource Center

Indirect measures: EuroQol EQ-5D 5 questions in 5 domains of health –Mobility, self-care, usual activity, pain/discomfort, or anxiety/depression –245 health states. Basis of domain weights: –Past studies based on British community sample –New US weights recently published Health Economics Resource Center

How to get the EuroQol EQ-5D Nonprofit research can obtain the EQ-5D for free from the EuroQol Group ( See Dolan, Gudex, Kind, & Williams (1997) for British-based EQ-5D See Shaw, Johnson, & Coons (2005) for US-based EQ-5D Health Economics Resource Center

Indirect measures: the QWB Quality of Well-Being Scale Two versions –Interviewer or self-administered (QWB-SA) QWB-SA is more feasible, but still takes time –76 questions; 1215 health states defined; –Includes symptoms, mobility, physical activity, & social activity Basis of domain weights: –Primary care patients in San Diego, CA Health Economics Resource Center

How to obtain the QWB-SA Contact the UCSD Health Outcomes Assessment Program ( RE.html) to register and obtain the QWB For interview-administered version see Kaplan, Bush, & Berry (1975) For self-administered version see Kaplan, Ganiats, & Sieber (1996) Health Economics Resource Center

Indirect measures: SF-6D Converts SF-36 or SF-12 scores to utilities –When based on SF-36, uses 10 items –When based on SF-12, uses 7 items 6 health domains –physical functioning, role limitations, social functioning, pain, mental health, and vitality Defines 18,000 health states Basis of domain weights –British community sample Health Economics Resource Center

How to obtain SF-6D Both SF-36 and SF-12 can be obtained from and the scoring algorithm for the SF-6D can be obtained from its developer, John Brazier. For converting the SF-36 into utilities see Brazier, Roberts, & Deverill (2002) For converting the SF-12 into utilities see Ware, Kosinski, & Keller (1996) Health Economics Resource Center

Health related quality of life in clinical trials (note of caution) Gathering HRQoL (i.e. measuring health status) in clinical trials may have one or more purposes: –Define the health states that might be experienced during the disease progression; –Define the health states that are experienced by each participant in a study; –Establish the preferences or utilities for each health state, as defined by the patients with the medical condition. Health Economics Resource Center

Health related quality of life in clinical trials Define the health states that might occur –to define the physiologic stages of the condition; Define the health states that do occur – to model QALYs for a CEA, Establish the preferences of each health state – to compare patient with community samples and other studies. Health Economics Resource Center

Which method to use? Trade-off between sensitivity and burden Start with a literature search 58

HRQoL – Note of caution Be sure your purpose is clear, before you choose your measurement tool ! 59

Hierarchy of methods Going from least burdensome to most: –Off-the-shelf utility values –Indirect Measures  (HUI, EQ-5D, QWB, SF-6D) –Use disease-specific survey during trial and transform later to preferences –Direct measure (SG, TTO) Health Economics Resource Center

Off-the-shelf values Use preference weight determined in another study for health state of interest –Not all health states have been characterized Useful in decision modeling Health Economics Resource Center

Indirect measures (HUI, EQ-5D, QWB, SF-6D) Standard surveys that are widely used Review published studies on psychometric properties in the population of interest May lack “responsiveness ” –i.e. may not reflect changes in health states caused by intervention (or of interest) Health Economics Resource Center

Using disease-specific surveys If consequences of the treatment or disease are not captured with a generic measure Use disease specific quality of life instrument Have community respondents value health states with a direct measure at a later time Health Economics Resource Center

Using disease-specific surveys Key methods issues: –Difficult to describe health state to community respondent –Difficult to establish values when there are a large number of possible health states Expensive, but potentially sensitive to variations in quality of life for this disease Often used in addition to generic measure Health Economics Resource Center

Direct Method (SG, TTO) May be necessary if effects of intervention are complex: –Multiple domains –Effects not captured in indirect or disease- specific instruments Health Economics Resource Center

Direct Method (SG, TTO) High variance in estimates from patients in a trial –Reflect risk aversion, feeling about disability –High variance = large sample size Not the “community value” specified by Gold et al Health Economics Resource Center

Important Resources Harvard Center for Risk Assessment – Brazier J, Deverill M, Green C, Harper R, Booth A. A Review of the use of health status measures in economic evaluation. Health Technol Assess 1999;3(9). – Health Economics Resource Center

Important Resources Table of published utility weights (preferences) for different health states – 68

HERC PL Sinnott, Joyce, JR, Barnett, PG. Preference Measurement in Economic Analysis. Guidebook. Menlo Park, CA. VA Palo Alto Health Economics Resource Center _419.pdf Health Economics Resource Center

Next Class April 28, 2010 Modeling Utilities over Time Vilija Joyce, M.S. 70

QUESTIONS and COMMENTS Health Economics Resource Center