“RE quantification of risk: the variables are orthogonal. Wouldn’t a calculation based on sum of squares be more reasonable?”
IGH GCP Ref: 5.0.3
You are correct, that the variables are uncorrelated and hence can be treated independently, and your approach would make good sense. At this stage in the industry’s maturity in this area we are trying to keep things simple and accessible and basically using the scoring as a means of prioritization and assist with determining proportionate responses. We have no doubt that more sophisticated algorithms will develop over time as acceptance and experience grow.
At TRI we are always researching new techniques to be more accurate in the way we measure and detects risk, but we also have to be careful not to overrun our core audience and confuse people more than we help them!