Transcript Quantitative vs. Qualitative Risk Assessment/Analysis
Relevance of Risk Analysis/Assessment to International Trade and the Precautionary Principle Tom Kasari, DVM, MVSc
Diplomate, American College Veterinary Preventive Medicine (Epidemiology) Diplomate, American College Veterinary Internal Medicine
Presented by: Stan Bruntz, DVM MPH
USDA-APHIS-VS Center for Epidemiology and Animal Health Fort Collins, Colorado
Agenda
• • • Review relevance of risk analysis/assessment to international trade and the Precautionary Principle Review risk analysis process and its component risk assessment procedure Review quantitative versus qualitative risk assessment methodologies
Relevance of Risk Analysis/Assessment to International Trade
• As per WTO (1995) Multilateral Trade Agreements, the Agreement on the Application of Sanitary and Phytosanitary Measures (the “ requirements SPS Agreement ”) sets out for member countries the basic rules for food safety and animal and plant health
159 out of 196 Countries in the World are WTO Members
As of March 2013 Map source: www.wto.org/english/thewto_e/countries_e/org6_map_e.htm
Relevance of Risk Analysis/Assessment to International Trade ( WTO SPS Agreement )
• WTO Article 5.1: “Members shall ensure that their sanitary or phytosanitary measures are based on an assessment, as appropriate to the circumstances, of the risks to human, animal or plant life or health, taking into account risk assessment techniques developed by the relevant international organizations ” Source: http://www.wto.org/english/thewto_e/coher_e/wto_oie_e.htm
Relevance of Risk Analysis/Assessment to International Trade ( WTO SPS Agreement )
• WTO Article 5.1: health: or phytosanitary measures are based on an assessment, as appropriate to the circumstances, of the risks to human, animal or plant life or health, taking into account risk assessment techniques developed by the relevant international organizations” Source: http://www.wto.org/english/thewto_e/coher_e/wto_oie_e.htm
Relevance of Risk Analysis/Assessment to International Trade ( WTO SPS Agreement )
•
WTO SPS Measures Article 5.1 is basis for using OIE guidelines for risk analysis (& component risk assessment) process
– OIE Terrestrial Animal Health Code (2013)– Vol I: Section 2; Chapter 2.1. Import Risk Analysis
Relevance of Risk Analysis/Assessment to International Trade ( WTO SPS Agreement )
• Besides assessment of risk, other key concepts contained in the SPS Agreement: – Harmonization – – – – Equivalence Regionalization & compartmentalization Transparency Notification
Relevance of Risk Analysis/Assessment to International Trade ( WTO SPS Agreement )
• Governments encouraged to “harmonize” their animal health standards based on international standards, guidelines, and recommendations developed in other international organizations (i.e. OIE)
Relevance of Risk Analysis/Assessment to International Trade ( WTO SPS Agreement )
• • Governments encouraged to “harmonize” their animal health standards based on international standards, guidelines, and recommendations developed in other international organizations (i.e. OIE) Harmonization means the establishment, recognition and application of common sanitary and phytosanitary measures
Relevance of Risk Analysis/Assessment to International Trade ( WTO SPS Agreement )
•
National standards do not violate the SPS Agreement simply by differing from international norms (non-harmonized)
– – Requirements can be stricter Justify on basis of analysis of scientific evidence and the risks involved
Equivalence
• Trading partners recognition that significantly different animal health and production systems can provide equivalent animal and human health protection for the purpose of international trade – Infrastructure – – – – Surveillance policies and/or operating procedures Laboratory systems Border security Internal movement controls
Regionalization (Zoning)
• Region/Zone means a clearly defined
geographical area
(country, part of a country, parts of several countries, several countries) containing an
animal subpopulation
status with respect to a specific for which required surveillance, control and biosecurity measures have been applied for the purpose of
trade
.
with a distinct health
disease international
Compartmentalization
•
Compartment
– means one or more
animal disease
or specific for the purpose of
establishments
under a common biosecurity management system containing an
subpopulation
with a distinct health status with respect to a specific
diseases
for which required surveillance, control and biosecurity measures have been applied
international trade
.
Definition
• Recognition of animal populations of different health status – Zoning/regionalization • Geographical basis – Compartmentalization • Management and biosecurity
Zones and compartments
• Both concepts are similar • The difference is the responsibility of the application of biosecurity measures – Disease-free zones Official sector – Compartments Private sector • Need for close supervision and accreditation by the official veterinary service
State’s swine industry
Regionalization
Interstate Trade Interstate Trade Regionalization = establishing and maintaining a disease free status for a subpopulation of animals based on a geographical basis
Compartmentalization
State’s swine industry Interstate Trade Interstate Trade
Compartmentalization
= establishing and maintaining a disease free status for a subpopulation of animals based on management systems related to management and biosecurity
Relevance of Risk Analysis/Assessment to International Trade ( WTO SPS Agreement )
• Risk analysis and regionalization or compartmentalization depend on the data generated by a soundly designed comprehensive surveillance system – Epidemiology is a key element in providing the scientific basis to satisfy international trade requirements
Relevance of Risk Analysis/Assessment to International Trade ( WTO SPS Agreement )
• • Risk analysis and regionalization depend on the data generated by a soundly designed comprehensive surveillance system “Harmonization”, “equivalence” “transparency”, and “notification” are the basis for mutual trust between veterinary services of trading partners
Trade ( Relevance of Risk Analysis/Assessment to International WTO SPS Agreement ) and Precautionary Principle
• Precautionary principle: If an action or policy has a suspected risk of causing harm to the public or to the environment, in the absence of scientific consensus that the action or policy is harmful, the burden of proof that it is not harmful falls on those taking an action .
Trade ( Relevance of Risk Analysis/Assessment to International WTO SPS Agreement ) and
Precautionary
Principle
• Precautionary Principle tempered by risk assessment requirement of WTO trading partners when it comes to matters of potential onerous animal health regulations “If in doubt, keep it out” zero-risk approach to mitigating animal health-related trade issues is unacceptable
Relevance of Risk Analysis/Assessment to International Trade ( WTO SPS Agreement ) and Precautionary Principle
• Relevance of Precautionary Principle to (WTO) Article 5.1: “…even if a (WTO) Member follows a precautionary (principle) approach, its SPS measures need to be ‘based on’ (i.e., ‘sufficiently warranted’ or ‘reasonably supported’ by) a risk assessment. Or, to put it another way, such an approach needs to be applied in a manner consistent with the requirements of (WTO) Article 5.1.” Source: http://www.wto.org/english/res_e/booksp_e/analytic_index_e/sps_02_e.htm
Validity Criteria for Sanitary and Phytosanitary Measures in International Trade
Source: Zepeda C., et al. 2001. Preventive Veterinary Medicine 48: 261-271.
Risk Analysis/Assessment
Review Concepts
• • • • What is risk?
What is risk analysis?
What is risk assessment?
Risk analysis and assessment processes
What is Risk?
• The likelihood of the occurrence and the likely magnitude of consequences (biologic & economic) of an adverse event or effect to animal or human health Source: OIE Terrestrial Animal health Code 2011 (glossary)
Elements of Risk
• • • • Probability (likelihood or chance) of an adverse event (the hazard) Consequences (or impact) – – Biologic Economic Uncertainty Ability to manage
Critical Questions That Should Shape Any Animal Health-Based Risk Analysis
• What can go wrong?
• How likely is the event(s) to occur?
• If the event(s) happen, what is/are the consequence(s) and extent of damage?
What is Risk Analysis?
• Organized way to answer those three questions…… as well as incorporate: • • • What can be done to change (mitigate) the risk?
Whom do we need to inform?
What/how do we need to communicate?
What Is Risk Analysis?
How likely is the event to occur?
If the event happens, what are the biologic and economic consequences?
What can go wrong?
What can be done to change (mitigate) the risk?
What must be done to implement mitigation(s)?
Hazard Identification Risk Assessment Risk Management Risk Communication Whom do we inform?
What/how do we need to communicate information?
Source: OIE Terrestrial Animal Health Code (2013)– Vol I: Section 2; Chapter 2.1.
http://www.oie.int/index.php?id=169&L=0&htmfile=chapitre_1.2.1.htm
Risk Analysis does NOT:
• • • • Establish the “acceptable risk” level Describe with certainty when/if an agent will be introduced or the consequences Determine policy Provide the ONLY input into decision making 33
What is Risk Assessment?
• Evaluation of the likelihood of entry , establishment , and spread of a disease and the associated potential biological and economic consequences to animal and/or public health Hazard Identification Risk Assessment Risk Communication Risk Management
Risk Assessment
• Consists of: – Entry (release) assessment – – – Exposure assessment Consequence assessment • • Biologic Economic Risk estimation Source: OIE Terrestrial Animal Health Code (2013)– Vol I: Section 2; Chapter 2.1.
http://www.oie.int/index.php?id=169&L=0&htmfile=chapitre_1.2.1.htm
Entry (Release) Assessment
• • Describes the biological pathway(s) necessary for an importation activity to 'release' (introduce) a pathogen into a particular environment – Pathways analysis Estimates the probability of that complete process occurring, qualitatively (in words) or quantitatively (as a numerical estimate)
Pathways Analysis Definition
Systematic assessment of the pathways along which a foreign animal disease agent might enter the US and establish an outbreak of disease in animals and/or man
Pathways Analysis
• • Systematic assessment of the pathways along which a foreign animal disease might enter the US and establish an outbreak of disease in animals and/or man Also applicable for delineating the pathways along which a domestic disease agent might spread from a state/province or region to new state(s)/province(s) or region(s)
Pathways Analysis
Its Uses
• • • Risk assessment Targeted surveillance planning Emergency preparedness and response
Pathways Analysis Steps
Step 1:
Establish an understanding of host, agent, and environmental interactions for the disease in question based on scientific literature, expert opinion, personal experience or other sources of information.
Pathways Analysis Steps
• Establish an understanding of host, agent, and environmental interactions for the disease in question based on scientific literature, expert opinion, personal experience or other sources of information.
Step 2:
Develop a list of potential pathways for entry of the disease agent into a susceptible livestock and/or human population
Pathways Analysis Steps
• Establish an understanding of host, agent, and environmental interactions for the disease in question based on scientific literature, expert opinion, personal experience or other sources of information.
• Develop a list of potential pathways for entry of the disease agent into a susceptible livestock and/or human population
Step 3:
Evaluate the feasibility of each pathway
Pathways Analysis Steps
• Establish an understanding of host, agent, and environmental interactions for the disease in question based on scientific literature, expert opinion, personal experience or other sources of information.
• Develop a list of potential pathways for entry of the disease agent into a susceptible livestock and/or human population • Evaluate the feasibility of each pathway •
Step 4:
Identify the populations at-risk for each feasible pathway that the disease agent follows to enter the country (or state/province or region)
Gaps in knowledge reduces the certainty of the confidence to place on feasibilty of some pathways
Exposure assessment
• • describes the biological pathway(s) necessary for exposure of animals and humans in the
importing country (or
state) to the
hazards
released from a given
risk
source Estimate the probability of the exposure(s) occurring, either qualitatively (in words) or quantitatively (as a numerical estimate) – animal and/or people
•
Consequence assessment
Describes the relationship between specified exposures to a biological agent and the consequences of those exposures – Direct consequences • animal infection, disease, and production losses – • public health consequences.
Indirect consequences • surveillance and control costs • • • compensation costs potential trade losses adverse consequences to the environment
Risk estimation
• Integration of the results from: – – – Release assessment Exposure assessment Consequence assessment
Quantitative Versus Qualitative Risk Assessment
‘zero’ risk does not exist
50
Types of risk assessment
•
Quantitative
•
Qualitative
•
Quantitative Risk Assessment
an assessment where the outputs of risk are expressed numerically – Objective in nature – This number can represent the probability of an event occurring during a specific time frame • Disease “X” will enter The Bahamas one out of every 10,000 shipments of product “a”
Quantitative studies
Advantages
• • • More profound Notion of the probability of occurrence of an adverse event Informed decison making
Disadvantages
• • • Require time Require good quality data Not possible to apply in all circumstances
yes
Scenario Tree
yes yes animal infected?
RISK yes Susceptible species exposed?
no Survives processing?
Detected at inspection?
NO RISK no yes no NO RISK NO RISK Herd infected?
no NO RISK no NO RISK
Uncertainty
• • • There are no exact values for each parameter It is necessary to produce an estimate that incorporates uncertainty and variability Use of simulation programs
Results
1 0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0 0.25
X <=0 5% 0.2
0.15
0.1
0.05
0 0 X <=0.01
95% 3 6 Values in 10^-3 9 12 • Not a point estimate but a range of probabilities • The result reflects variability and uncertainty 56
Qualitative Risk Assessment
• • Not always possible to quantify risks because there simply may not be enough data to make reliable calculations An assessment where the outputs for the likelihood of the outcome or the magnitude of the consequences are expressed in qualitative terms such as ‘ high ’, ‘ medium ’, ‘ low ’ or ‘ negligible ’ – Subjective in nature
Qualitative studies
Advantages
• Faster • Applicable to a broader scope of circumstances
Disadvantages
• • • Less profound Do not provide a numerical probability of occurrence of an adverse event Less precise decision-making
Risk Analysis Process
Hazard Identification Risk Assessment Risk Management Risk Communication Source: OIE Terrestrial Animal Health Code (2013)– Vol I: Section 2; Chapter 2.1.
http://www.oie.int/index.php?id=169&L=0&htmfile=chapitre_1.2.1.htm