economic consequences of antimicrobial resistance mark...
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Economic consequences of antimicrobial resistance
Antimicrobial Resistance (AMR) in the Asia Pacific & Its impact on Singapore,
Singapore, 13‐14 November 2018
Mark Jit1,2,3
1Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine
2Modelling and Economics Unit, Pubic Health England3School of Public Health, University of Hong Kong
04 December 2018I have no conflicts of interest to declare.
Overview
Why bother about the economic consequences of AMR?
How do we measure the cost of AMR? Hospital case‐control studies
Limitations of hospital studies
Capturing wider economic consequences
Economic goodsPrivate goods Common goods Public goods
Rivalrous, excludable Rivalrous, non‐excludable
Non‐rivalrous, non‐excludable
Antibiotic use
Antibiotic use and economic goods
Generates private goods to users
(may expedite clearance of bacterial infection and recovery
from illness)
Consumes global common goods
(antibiotic effectiveness is depleted)
Negative externality ‐ cost imposed on someone other
than the user.
Because of this externality, a free market will not allocate resources around antibiotics and AMR optimally.
Market failure
Antibiotic consumption
Generates private goods, consumes common goods
Over‐consumption of antibiotics
R&D in new last‐resort antibiotics
Generates common
goods but few immediate
private goods
Under‐investment in antibiotic R&D
Infection control e.g. vaccines
Generates common goods by avoiding
antibiotic use
Under‐investment in
infection control
Governments can overcome market failure by policy instruments e.g. taxes, subsidies and regulations.
However, the size of an efficient intervention must be calibrated to the size of the negative externality.
This requires accurate estimation of the economic cost of AMR.
Correcting market failure
COST OF ILLNESS
HEALTH LOSS
OPTION A OPTION B
Economic evaluationsA (full) economic evaluation compares the incremental costs
and consequences of an intervention compared to a comparator
COST OF ILLNESS
HEALTH LOSS
COST OF INTER‐
VENTION
COST OF ILLNESS
HEALTH LOSS
OPTION A OPTION B
Economic evaluationsA (full) economic evaluation compares the incremental costs
and consequences of an intervention compared to a comparator
COST OF ILLNESS
HEALTH LOSS
COST OF INTER‐
VENTION
AMR IMPACT
AMR IMPACT
Questions that we might address
Prioritisation in the AMR space
Should we invest in:
Antibiotic stewardship
R&D for an antibiotic
R&D for a vaccine that prevents a resistant
organism
Prioritisation in the infection prevention
space
Should we invest in:
Risk based vs universal screening for
neonatal GBS
Introduction of PCV vs rotavirus vaccine
Relationships
Antimicrobial use
Antimicrobial resistance
Health outcomes
Economic costs
Interventions 1
2 3
45
6
“Economic burden of AMR”
Cohen et al. Medical Care 2010; 48:767.
Difference in clinical outcomes, length of stay and costs between hospital patients with resistant vs. susceptible infections.
Cost of a resistant infection in hospital
Cost per resistant infection
Naylor et al. Antimicrobial Resistance and Infection Control 2018; 7:58.
Gandra et al. Clin Microbial Infect 2014; 20:973.
Residual confounding e.g. comorbidities Time dependent confounding (may be averted by
multistate models) Confounding due to length of hospital stay prior to
infection onset Appropriate counterfactual: sensitive case or no
disease? Limited follow‐up time Limitations in time, space and economic perspective
Methodological challenges with hospital studies
Naylor et al. Antimicrobial Resistance and Infection Control 2018; 7:58Gandra et al. Clin Microbial Infect 2014; 20:973.
Expanding the cube
Extension in space from one hospital to
national/global estimates
Extension in time from the present to
the long‐term
Extension in perspective from the
health care payer to societyAdditional cost of
treating resistant cases in hospital‐based studies
Extrapolation in space
Number of hospital cases of resistant disease
Excess cost of treating one resistant case
+Excess cost of
reduced productivity due to illness and
premature death
=From hospital case‐control
studiesFrom patient surveys and national
statistics on income and workforce
participation
External validity: heterogeneity in case loads, care patterns, study populations, pathogen distribution etc.
Costs (esp. productivity) beyond the hospital: Primary care Community (non‐medically attended
illness)
Extrapolation in space: issues
CDC infographic based on Marks et al. Emerg Inf Dis 2014.
Extension in timeExcess cost of treating resistant cases underestimates costs in the
future when bacteria may acquire multiple resistances.
Extension in time
Resistance (and multi‐drug
resistance) becomes more common.
Unit cost of treatment rises.
Classes of antibiotics become
ineffective.
New antibiotics need to be developed.
Hospital procedures become risky to perform because
infections cannot be treated.
Other procedures (e.g. surgery) become costly
and dangerous.
Laxminarayan and Brown. J Environ Eco & Management 2001; 42:183.Smith and Coast. BMJ 2013; 346:f1493.
Infections spread more because infection control
is more ineffective.
TODAY
Extension in perspective
Hospital perspective
• Cost of providing hospital care
Societal (microeconomic) perspective
• Out of pocket payments
• Health care outside hospital setting
• Productivity loss due to caregiving
• Productivity loss due to premature mortality
• Price of human suffering (valued using QALYs, DALYs or VSLs)
Societal (macroeconomic) perspective
• Loss in economic activity from reduced demand and labour supply due to both sicknessand to avoided economic activities (e.g. travel)
Macroeconomic impact of AMR
Antimicrobial resistance
Mortality
Morbidity
Labour supply
Economic output
Cost of goods
Demand for goods
Labour productivity
These relationships have been modelled using Computable General Equilibrium (CGE) methods (Smith et al., 2006) and Social Accounting Matrix (SAM) methods (KPMG, 2014).
Global/multinational estimates of AMR costsStudy Cost estimate Health impacts Economic impactsWorld Bank (2017)
$1‐3.4 trillion per year in 2030 (1.1‐3.8% of global GDP)
Increased mortality.
Reduced labour supply.
RAND (2014) $0.18 ‐ 9.8 trillion per year in 40 years (0.06 ‐3.06% of global GDP)
Increased mortality.
Reduced labour supply.
Increased morbidity.
Caregiving, workplace absence, reduced productivity.Reduced inter‐sectoral transactions and trade.
KPMG (2014) 1.66 ‐ 6.08% of global GDP in 2050
Increased mortality.
Reduced labour supply.
Increased morbidity.
Increased treatment costs, reduced productivity.Reduced economic production.
ECDC and EMA (2009)
€1.5 billion per year in the EU, Iceland and Norway (2009).
Increased morbidity.
Reduced labour supply.
Increased morbidity.
Increased treatment costs, reduced productivity.
Conclusions
Understanding the economic cost of AMR is vital to inform interventions that can correct AMR‐related market failures.
Most studies are limited to short‐term health care provider costs for patients from a single hospital. These studies underestimate the total cost of AMR by ignoring future trends, non‐hospital costs and effects on the wider economy.
A few studies with extended scope, perspective and time horizon forecast the cost of AMR to be in $trillions by the mid‐21st century. However, they have had to rely on greatly simplified assumptions and data inputs.