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Valuing intangible costs of substance abuse in monetary terms
Claude Jeanrenaud, Sonia Pellegrini IRER, University of Neuchâtel
NeuchâtelOctober 25th, 2003
Purpose
(1) Defining the notion of « intangible costs »
(2) Discussing some of the methodological questions that arise when valuing the intangible costs of addictive products
What are intangible costs ?
Substance abuse generate:
Tangible vs. intangible costs
Intangible costs :change in health-related quality of life (HRQOL),excluding any direct and indirect costs
Tangibles costs :• forgone production• material costs
Both the tangible and the intangible costs affect the well-being
Economic implicationsof substance abuse
health per se
change in well-being
non health
reduced HRQOL forgone production
intangible tangible
Ignoring this component because we don’t know how to measure it leads to a gross under-estimation of the consequences of substance abuse
When both tangible and intangible costs are valued, the latter constitute a considerable part of the total costs:
– Violent crime : 82.6%
– Multiple sclerosis: 89.9%
– Smoking : 50.0%
– Alcohol abuse : 66.2%
Can intangible costs be ignored?
Intangible costs are the monetary (or income) equivalent of the loss of health per se
Most studies only value direct and indirect costs (tangible costs)
Intangible costs are said to be difficult or impossible to assess
Missing markets : one cannot rely on market prices to place a value on changes in HRQOL
Valuing intangible costs
Conversion of health units (natural units) in money units
Health implications of alcohol abuse
natural units
conversion
income equivalent = money unit
A preference- or non preference-based approach ?
A restricted or a global approach ?
A disaggregated or an all-inclusive approach ?
A one-step or two steps procedure ?
Survey design
Some methodological issues
Preference- or non preference-based approach
The conversion of natural units in monetary terms is based on preferences
People are asked how they would trade health against money
Income equivalent of a reduced HRQOL
Method : contingent (CV) survey
Preference-based (willingness-to-pay approach)
CV method : allows us to learn how people value health
People are asked to state :
the maximum amount of the income they would accept to forgo to avoid a deterioration of their health state (keeping their well-being constant)
Income equivalent of a reduced HRQOL
The analyst decides how much people would pay to avoid drug harm (hypothesis)
Non preference-based (short cut)
Bernasconi (1993) : for each drug user, there is at least a member of the household who would accept to sacrifice all his assets.
Collins & Lapsley (1996): The value of the goods that the deceased would have consumed plus a lump sum amount for each year of life lost provide a lower bound for the intangible costs
Restricted or global approach ?
Restricted or global approach ?
Both the HC and the WTP methods can be used in a global or restricted perspective:
Human capital : – global if used to value all aspects of substance
use or abuse– restrictive if used to value only part of the
burden (resources costs)
WTP approach :– global if used to value all health and non-health
implications – restricted if use to value intangible costs only
WTP : global perspective
WTP global perspective: applied to assess all the costs borne by the community, i.e. tangible and intangible:
Difficulties :
– The stated value depends on which costs are carried by the social security system
– It doesn’t reflect the total cost for the community
WTP : restricted perspective
WTP restricted : applied to assess the intangible costs only
Difficulties :
– The questionnaire must be carefully designed so that the respondent does not take possible losses in future income or out-of-pocket payments when stating his WTP
– Is it sufficient to tell the respondents not to do it ?
Disaggregated or all-inclusive approach ?
Alcohol abuse has many health implications : Abusers face a higher risk for more than 60 diagnoses groups
Excessive alcohol consumption also has behavioral and psycho-social consequences
How to include all these effects in the cost estimate ?
Alcohol abuse is a complex problem
Procedure:
• Identify the adverse health effects related to excessive alcohol consumption
• Value the health implications of the most significant alcohol-related diseases
Problems:
– The risks for the different alcohol-related diseases are not independent
– Risk of overestimation (embedding effect, budget constraint)
Valuing each effect separately and summing them up
Procedure:
• Specify a life time profile for (typical) excessive drinkers
• Value the change in HRQOL using a CV survey
Problems :
– What is a representative abuser ?
– How to attach a probability to each profile ?
Valuing a profile
From health metrics to money metrics
From health metrics to money metrics
One-step conversion
Change in health state (natural units) is converted directly in monetary units
CV survey (profile or specific diagnoses)
Two-step conversion
Change in health state (natural units) is converted in utility units (QALY or DALY)
Utility weights are assessed through a time-trade-off or a standard gamble survey
Use an estimate of the income equivalent of a QALY or use some standard value
Survey design
Ex ante : WTP for a risk reduction
Ex post : WTP of a (potential or real patient) for retrieving perfect health
WTP is higher when ex ante approach is used
Ex ante or ex post approach
Real patients have a better knowledge of the health implications of the illness on their well-being
Potential patients tend to overstate the consequences of a specific disease (ex: potential patients would prefer to die, real patients prefer to live with the disease)
Surveyed population : real patients or potential patients
Sometimes, the respondents cannot imagine to be at risk. Example: a scenario in which an abstinent must imagine to be an alcoholic.
Alternative scenario : the respondent express his WTP to provide a treatment for a member of his family or a close friend.
What should the respondent consider : a change in his own health state
or in that of someone else ?