ABC Project Update
WP2: Discrete choice experiment design
Dyfrig Hughes, Emily Fargher, Val MorrisonABC Project Working MeetingSeptember 2009
Behaviourintention
Demographicse.g. age, gender
Personality
Past experience
Outcome expectancies Xoutcome value
Normative beliefsX motivation to comply
Perceived internal and external control factors
Attitude towardsbehaviour
Subjective norm
Perceived behaviouralcontrol
BEHAVIOUR
Time Pref. Questions(Economic theory)
LOT(Optimism)
TPB QuestionnaireAdapted MDQ
(Theory of planned behaviour)
MDQ Add On(Behaviour intention)
Bilateral Bargaining(Economic theory)
BMQ(Self-regulation theory)
Brief-IPQ(Self-regulation theory)
Health Beliefs Model
DCE(Stated preference)
MARS(Adherence measure)
Morisky(Adherence measure)
TPB: ABC Questionnaire Map
Prospect theory
Time preference
Humancapital
Questionnaire suggestions
Questionnaire No. items
Measure / Theory
MARS 5 Adherence
Morisky 8/4 Adherence
Breif_IPQ 9 Self-regulation theory
BMQ 11 Self-regulation theory
LOT_R 10 Optimism
TPB (Adapt_MDQ)
15 Theory of planned behaviour
Time Preference
4/2 Time preference
DCE 16 Stated preference
Discrete choice experiments Developed in the 1990s to elicit views on health care Based on the idea that goods and services are described
by characteristics (attributes) The levels of these characteristics determines the extent
to which the individual values these goods and service DCE is used to
Show how people are willing to trade between characteristics Produce overall benefit scores for alternative ways of providing
health care Estimate the relative importance of different characteristics of a
service Estimate whether an attribute is important
Example choice question
Rank
Binary choice
Varying levelsAttributes
Hypothetical scenario
Recent example
DCE methodology
1. Identification of attributes Policy, RCTs, literature Source: policy, RCTs, literature
2. Identification of associated levels ACTIONABLE, PLAUSIBLE and capable of being TRADED OFF
Cardinal (dose frequency OD, BD) Ordinal (severe vs. moderate ADR) Categorical (GP versus pharmacist)
3. Design choice scenarios4. Questionnaire 5. Input, analysis and interpretation
U = β1Sym + β2Freq + β3S_ADR + β4M_ADR ... + e
Checklist!Lancsar E. & Louviere J. (2008) Conducting discrete choice experiments to inform healthcare decision making. Pharmacoeconomics 26(8): 661-677.
Stage 1&2
Stage 3: Choice scenarios
Greater the number of attributes and levels, the greater the number of possible profiles
Possible profiles = LevelsAttributes
2 attributes at 2 levels = 22 = 4 4 attributes at 4 levels = 44 = 256 3 attributes at 3 levels and 1 attributes at 2 levels
= 33 x 21 = 54 Design catalogue e.g. http://www.research.att.com/~njas/oadir/ 24 runs
Substantial questionnaire of Multiple pages Coast J., Flynn T.N., Sailsbury C., Louviere J., & Peters T.J. (2006)
Maximising responses to discrete choice experiments - a randomised trial. Appl Health Econ Health Policy 5(4): 249-260.
What next?
Confirm survey content Confirmation of questionnaires to be inc. in
survey Confirmation of DCE design (length)
Translation Validation of instruments Co-ordination of ethics Pilot – all countries?
ABC Project Update
WP3: Econ & psychological determinants review
Dyfrig Hughes, Emily Fargher, Val MorrisonABC Project Working MeetingSeptember 2009
ABC WP3
Systematic Review of behavioural models of adherence to medicines: Economic & psychological perspectives
T3.1 “Systematic review of the literature: Studies that have assessed the psychological and economic basis for non-compliance, together with structured models of compliance behaviour will be identified using computerised search in relevant databases, retrieved and analysed.”
Review Question: Which models in the economics and psychology literature may explain adherence to medicine?
Search strategy
A series of independent search strategies, across databases, will be used to identify papers in the economics and psychology literature.
For consistency the search strategy used to identify adherence papers in WP1 will be used throughout this work package.
Databases to be searched: MEDLINE, EMBASE, The Cochrane Library, CINAHL, PsycINFO, PsycLit, EconLit
Inclusion Criteria: Papers containing EMPRICIAL data reporting adherence OR reporting a behavioural model or theory or adherence
Exclusion Criteria: Non-pharmaceutical studies
Search strategy stages
Search OneEconomic models
based on cost
1. Adherence terms2. Cost terms3. 1 AND 24. Limit 3 to review
Search TwoEconomic models
exc. cost
1. Adherence terms2. Econ theory terms3. 1 AND 2
Search ThreeAll other
economic models
1. Adherence terms2. Generic catch all3. Econ Eval. terms 4 2 NOT 35. 1 AND 4
Search FourPsychological models
1. Adherence terms2. Psychological theory terms3. 1 AND 2
Search FiveAll other
psychological models
1. Adherence terms2. Generic catch all 3. 1 AND 2
Economic models Psychological models
screen all papers using the same criteria
Strategy examples
What next?
Held teleconference and decided …
Run searches & re-convene in October to agree next stage: Independent screen of titles and abstracts by 2 reviewers Data Extraction:
Study characteristics Measure of adherence (+ critique of measure of adherence) Key Findings Behavioural model e.g. Consumer choice theory, Theory of planned
behaviour etc. (+ Critique of experiment used to test model)
Final stage: using results of review & expertise within the group develop the model.
Thank you
Dyfrig Hughes, Emily Fargher, Val MorrisonABC Project Working MeetingSeptember 2009