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					 Introduction to Effectiveness,
Patient Preferences and Utilities

    Patsi Sinnott, PT, PhD, MPH
     HERC Economics Course
            June 13, 2006
                    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
• Review of the most frequently used preference
  measurement systems
• Preference measurement in clinical trials
• Guidelines on selecting measures

                   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.
• 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).
                  Health Economics Resource Center
          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”.




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         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




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          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;
                                            * From Ware, et al., SF-36
                                            Health Survey Manual




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          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




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    Instruments to measure HRQoL

• Generic instruments:
  • SF-36: 8 dimensions of health, including
    physical functioning, bodily pain, social
    functioning and mental health.




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    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


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                 CEA/CUA
•CEA compares the costs and effectiveness of
two (or more) interventions
         (Coststudy  Costusual care)
Effectiven essstudy  Effectiven essusualcare



                 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
                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
• 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 0.5

                 Health Economics Resource Center
  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


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          White board exercise
• In CEA what components of health status will
  you need to measure ?




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


                 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: individuals respond to composite
    descriptions of health states (their own or
    written descriptions)

  • Indirect: individuals respond to questions about
    separately delineated dimensions (or attributes)
    of a health state, and a summary score or utility
    weight is calculated.
     • Physical function
     • Social functioning
     • Mental health etc.
                   Health Economics Resource Center
Sample health state description (composite)
• 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)




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     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.
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        Direct: Time Tradeoff (TTO)

•How much
reduction in
total life willing
to give up in
order to live in
perfect health




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       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
   • Scores are aggregated to create a composite
     preference or utility weight for a health state




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       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
• 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.

                  Health Economics Resource Center
   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
  (www.healthutilities.com)
• For an overview of the HUI see Horsman,
  Furlong, Feeny, and Torrance (2003)




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  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
  (www.euroqol.org)
• 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
  • Original interviewer-administered
  • More recent 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
  (http://www.medicine.ucsd.edu/fpm/hoap/inde
  x.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
  www.sf-36.org 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 – in
  order to define the physiologic stages of the
  condition;
• Define the health states that do occur – to be
  used in modeling QALYs for a CEA, using
  previously established preferences for each
  health state experienced;
• Establish the preferences of each health state –
  to compare patient with community samples
  and other studies.
                  Health Economics Resource Center
Health related quality of life in clinical
        trials (note of caution)

  • Be sure your purpose is clear, before
    you choose your measurement tool




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       Which method to use?


• Trade-off between sensitivity and burden
• Start with a literature search




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           Hierarchy of methods
• Going from least burdensome to most:
  • Off-the-shelf utility values
  • Indirect Measures
     • (HUI, EQ-5D, QWB, SF-6D)
  • Use a disease-specific survey during the trial
    and transform at a later time 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 not reflect changes in health states caused
  by intervention (or of interest)
   • May lack “responsiveness ”



                  Health Economics Resource Center
      Using disease-specific survey

• 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 survey
• 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 disease-specific
     instrument




                  Health Economics Resource Center
        Direct Method (SG, TTO)

• High variance in estimates from respondents
   • 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
   • http://www.hcra.harvard.edu/
• 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).
   • http://www.hta.nhsweb.nhs.uk/
• Table of published utility weights
  (preferences) for different health states
   • http://www.tufts-nemc.org/cearegistry/
                 Health Economics Resource Center
                       HERC
• PL Sinnott, Joyce, JR, Barnett, PG. Preference
  Measurement in Economic Analysis.
  Guidebook. Menlo Park, CA. VA Palo Alto
  Health Economics Resource Center. 2007
  http://www.herc.research.va.gov/files/BOOK_
  419.pdf



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