Multi-Criteria Decision Analysis Tools for Prioritising Emerging or Re-Emerging Infectious Diseases Associated with Climate Change in Canada

Abstract

Global climate change is known to result in the emergence or re-emergence of some infectious diseases. Reliable methods to identify the infectious diseases of humans and animals and that are most likely to be influenced by climate are therefore required. Since different priorities will affect the decision to address a particular pathogen threat, decision makers need a standardised method of prioritisation. Ranking methods and Multi-Criteria Decision approaches provide such a standardised method and were employed here to design two different pathogen prioritisation tools. The opinion of 64 experts was elicited to assess the importance of 40 criteria that could be used to prioritise emerging infectious diseases of humans and animals in Canada. A weight was calculated for each criterion according to the expert opinion. Attributes were defined for each criterion as a transparent and repeatable method of measurement. Two different Multi-Criteria Decision Analysis tools were tested, both of which used an additive aggregation approach. These were an Excel spreadsheet tool and a tool developed in software ‘M-MACBETH’. The tools were trialed on nine ‘test’ pathogens. Two different methods of criteria weighting were compared, one using fixed weighting values, the other using probability distributions to account for uncertainty and variation in expert opinion. The ranking of the nine pathogens varied according to the weighting method that was used. In both tools, using both weighting methods, the diseases that tended to rank the highest were West Nile virus, Giardiasis and Chagas, while Coccidioidomycosis tended to rank the lowest. Both tools are a simple and user friendly approach to prioritising pathogens according to climate change by including explicit scoring of 40 criteria and incorporating weighting methods based on expert opinion. They provide a dynamic interactive method that can help to identify pathogens for which a full risk assessment should be pursued.

Best practices in ranking communicable disease threats: a literature review, 2015

“…The studies used one of five methodologies to rank communicable disease risks: bibliometric index [33,34], the Delphi technique [35][36][37][38], Multi-Criteria Decision Analysis (MCDA) [31,32,[39][40][41], qualitative algorithms [42,43], and questionnaires [29][30][31]45 In general, risk-ranking exercises begin with identifying diseases to consider for prioritisation, formulating a list of criteria to assess diseases against, then weighting the criteria according to importance, and scoring diseases against the criteria to create a ranking based on the scores.…”

“…The qualitative Likert assessments, which are based upon scales that typically range from 'strongly disagree' to 'strongly agree', are represented using a red-amber-green 'traffic light rating system' (with red indicating a high risk of bias likely). Where multiple articles described the same risk-ranking exercise, articles were appraised and extracted as one study, but counted individually within the flowchart (Figure 1) [28][29][30][31][32]. …”

“…Framework of best practice for risk ranking exercises, for use across methodologies, literature review on best practices in ranking communicable disease threats, 2015 Cardoen et al [39] Multi-criteria decision analysis 51 diseases ranked 5 criteria used Criteria weighted using Las Vegas method 7 participants weighted criteria 35 participants scored diseases Scores of 0-4 points allocated to each disease (based on occurrence and severity) Cox et al [31,32] Multi-criteria decision analysis 9 diseases ranked 40 criteria used Criteria weighted using a qualitative Likert scale (based on likelihood or importance) 64 participants weighted criteria 47 participants scored diseases Likert scale used to score diseases Havelaar et al [40] Multi-criteria decision analysis 86 diseases ranked 7 criteria used Criteria weighted using relative ranking 29 participants Quantitative, scaled values used to score diseases Humblet et al [41] Multi-criteria decision analysis 100 diseases ranked 57 criteria (in 5 categories) 40 participants Criteria weighted using the Las Vegas method Co-efficients of 0-7 points assigned to each option Morgan et al [42] Qualitative algorithm 1 disease ranked (a worked example) 1 participant…”

“…The included studies often provided explanations for their choice of methodology in terms of overcoming or balancing the potential limitations of alternative methodologies, but rarely explained their choice of methods with regards to the specific objectives of their risk-ranking exercise. Five of the reviewed studies used a quantitative methodology [33][34][35]37,40,41], three used qualitative approaches [36,42,43], and six studies used semiquantitative, mixed methods [28][29][30][31][32]35,38,39,44]. Only four studies used either entirely qualitative or quantitative methods [33,34,42,43], however, these studies were considered by their authors to be most useful as part of a wider risk-ranking exercise rather than as a stand-alone methodology.…”

Epidemiological surveillance methods for vector-borne diseases

“…One of the biggest limiting factors to our understanding of patterns of disease is, in many cases, a lack of detailed knowledge of vector ecology. Since vector distribution, movement and life cycles are influenced to a large extent by local and regional climatic factors, it stands to reason that climate and climate change have a large influence on patterns of VBD emergence (1,2,3,4). Another important factor influencing vector dynamics, at least on a local scale, is human-induced alteration of the vectors' breeding habitat, and this has resulted in important changes in the distribution of several VBDs in recent decades (3,5).…”