Assessing aeromedical risk: a three-dimensional risk matrix approach

Abstract

Early aeromedical risk ⁱ was based on aeromedical standards designed to eliminate individuals ⁱⁱ from air operations with any identifiable medical risk, and led to frequent medical disqualification. The concept of considering aeromedical risk as part of the spectrum of risks that could lead to aircraft accidents (including mechanical risks and human factors) was first proposed in the 1980s and led to the development of the 1% rule which defines the maximum acceptable risk for an incapacitating medical event as 1% per year (or 1 in 100 person-years) to align with acceptable overall risk in aviation operations. Risk management has subsequently evolved as a formal discipline, incorporating risk assessment as an integral part of the process. Risk assessment is often visualised as a risk matrix, with the level of risk, urgency or action required defined for each cell, and colour-coded as red, amber or green depending on the overall combination of risk and consequence. This manuscript describes an approach to aeromedical risk management which incorporates risk matrices and how they can be used in aeromedical decision-making, while highlighting some of their shortcomings.

Keywords: healthcare delivery; quality and outcomes of care; research approaches.

Figure 1

A risk matrix with associated red/amber/green (RAG) organisational risk acceptance=green acceptable to red unacceptable.

Figure 2

An example of a 4×4 aeromedical risk matrix, incorporating class of medical events with likelihood. Defining the acceptable risk and hence red/amber/green colour coding is an organisational responsibility.

Figure 3

Graduated risk matrices incorporating occupational role and differing classes of acceptable organisational risk for each aircrew category.

Figure 4

Search and rescue helicopter mountain hoist operation. Sudden incapacitation of either (category 1) pilot is likely to result in disaster. (Reproduced with permission from the Royal Canadian Air Force)

Figure 5

C-17 strategic transport flight deck. Incapacitation of either (category 2) pilot may result in a mission abort but is unlikely to compromise flight safety. (Reproduced with permission from the Royal Canadian Air Force)

Figure 6

Risk matrix/case 1. ACS, acute coronary syndrome; MI, myocardial infarction; SCD, sudden cardiac death.

Figure 7

Case 2/risk matrix.