Abstracts (PDF file, 1.8MB) - Society for Risk Analysis

SRA 2013 Annual Meeting Abstracts
W3-I.1 MacGillivray, BH; Cardiff University;
macgillivraybh@cardiff.ac.uk
Heuristics in policy relevant science: an analytical
framework for characterising the strengths and limits of
formal risk and decision analysis
Scholars long argued that one of the defining features of
science was that it is systematic and methodical. That is,
science was conceived as being governed by generally agreed
upon rules for designing experiments, analysing data, and
discriminating between conflicting hypotheses. Yet today this is
a rather unfashionable view amongst historians and
philosophers, with rules now seen as a somewhat peripheral
feature of scientific practice. However, focussing on formal risk
and decision analysis, this paper argues that the obituary of
rules has been prematurely written. It develops an analytical
framework for studying a particular class of rules: heuristics.
Risk research tends to view heuristics as lay reasoning devices
that are generally sub-optimal. In contrast, we follow Pólya and
Pearl in defining heuristics as rules of search, classification,
inference, and choice that fall short of formal demonstration,
yet that are indispensible for domains that did not admit of
formal logic or proofs. Analysing various domains of
environmental and public health governance, we identify
structurally similar rules of thumb used to screen potential risk
objects, to discriminate between signal and noise, to weight
evidence, to select models, to extrapolate beyond datasets, and
to make decisions based on agreed upon facts. We analyse the
origins of these heuristics, their justifications, the functions
that they play, their empirical adequacy, and the biases that
they introduce. Our basic claim is that heuristics play a central
role in how we collect, interpret, and act upon scientific
knowledge in governing risk; that this role is not necessarily
problematic; and that, above all, it needs to be taken seriously
if we are concerned with robust, evidence-based public policy.
T3-I.4 MacKenzie, CA; Naval Postgraduate School;
camacken@nps.edu
Deploying Simulation to Compare Among Different Risk
Reduction Strategies for Supply Chains
A firm can choose among several strategies to reduce the risk
of disruptions in its supply chain, including holding inventory,
buying from multiple suppliers, and helping suppliers recover.
Because these risk management strategies may be
non-continuous and depend on each other, simulation can be
used to select a near optimal combination of strategies. We
develop a conceptual framework for a firm who wishes to select
resilience strategies that maximize its profit. Because the risk
management strategies may be dependent upon each other,
finding the optimal mix of strategies becomes a difficult
combinatorial problem. For example, holding inventory may
maximize the profit of all the strategies examined in isolation,
but a combination of helping the supplier recover and buying
from an alternate supplier may result in a higher profit than
just holding inventory. Simulating multiple strategies together
can account for these interdependencies among the risk
management strategies. This increases the number of scenarios
the simulation will explore, which increases simulation time.
The trade-off between increasing the number of simulations to
assess the profit for a given scenario and exploring more
scenarios is similar to the trade-off that occurs when using
simulation to solve stochastic optimization problems.
P.139 Madden, M*; Young, B; Datko-Williams, L; Wilkie, A;
Dubois, JJ; Stanek, LW; Johns, D; Owens, EO; ORISE, U.S.
EPA-ORD, U.S. CDC-NIOSH; madden.meagan@epa.gov
Review of Health Effects and Toxicological Interactions of
Air Pollutant Mixtures Containing Oxides of Nitrogen
The U.S. EPA sets National Ambient Air Quality Standards
(NAAQS) to protect against health effects from criteria air
pollutants with the recognition that human populations are
exposed to complex air pollutant mixtures. Exposure to these
mixtures may differentially affect human health relative to
single pollutants as a result of biological interactions between
constituents of the mixture. If the effects of a mixture are equal
to the sum of the effects of individual components, the effects
are additive and the interaction effect is zero; additivity is often
assumed as the null hypothesis for interaction effects.
Alternatively, synergism (effects greater than additive) and
antagonism (effects less than additive) are possible
interactions, although the definitions and usage of these terms
are not consistent across studies. To understand the potential
biological interactions of exposure to air pollutant mixtures, we
reviewed toxicological evidence (animal and controlled human
exposure) from mixture studies cited in EPA’s Integrated
Science Assessments (ISAs) and Air Quality Criteria Documents
(AQCDs). We used quantitative and qualitative methods to
determine the effects of pollutant mixtures on all health-related
endpoints evaluated in these studies, specifically focusing on
mixtures containing oxides of nitrogen. Many studies could not
be analyzed quantitatively using our statistical model due to
incomplete reporting of data. Instead, studies with incomplete
response data were evaluated qualitatively for evidence of
interaction effects and relevant vocabulary such as “additivity,”
“synergism,” and “antagonism.” Although a number of studies
reported deviations from additivity, there was no discernible
pattern to the relationship between similar exposure scenarios
and the direction or magnitude of the biological response. The
views expressed in this abstract are those of the authors and do
not necessarily represent the views or policies of the U.S. EPA.
P.57 Maeda, Y*; Marui, R; Yamauchi, H; Yamaki, N; Shizuoka
University; tymaeda1@ipc.shizuoka.ac.jp
Comparative study of risk with nursing work in Japan and
China
Risk with nursing work, particularly medical incidents, in
hospitals in China and Japan was compared. Data about medical
incidents in Japan were obtained from the survey of 1,275
Japanese hospitals operated by Japan Council for Quality Health
Care in 2011. As for China, a questionnaire survey was
conducted from December 2012 to January 2013 among 631
nurses in Nanjing Drum Tower Hospital. As a result, situations
related to medical incidents, factors of medical incidents,
length of service of nurses who found the incidents, and the
season when the incidents occurred frequently were common in
Japan and China, whereas frequency of medical incidents were
different. In addition, satisfaction with work schedule of
nursing was investigated by several questions in the survey in
China. Satisfaction level with the schedule was very high in
average, however dissatisfaction was also found for some
questions. Independence of medical incident reporting and
satisfaction with scheduling was tested. In some questions,
significant relationship between dissatisfaction with schedule
and frequency of medical incidents were obtained. It suggests
that medical incidents are related to busyness of nursing work.
December 8-11, 2013 - Baltimore, MD