Williamtfgoossen at cs.com wrote: > It should be in OpenEHR in order to handle for instance pain scores > that do get a number quantity but has no unit > > of course then the question is still if CQuantityItem can hold > decimals as well for the VAS score which can be pain = 7.5, or 3.4 > *theoretically speaking, such 'quantities' are not true quantities - a true quantity is one that states the amount of some physical substance or flow, and by definition has units to measure that. Pain and other scores are not true quantities, they are just numbers. True quantities have the operations +and - defined on them. I doubt that pain scores could be meaningfully added for a single individual, let alone across individuals.
However ... the current specification allows DV_QUANTITYs to have an empty unit string, which allows for these pseudo quantities that are not modelled as Ordinals. We really should not do this. Instead we should have an equivalent of DV_ORDINAL that allows fractional values - Ordinals only have ordered, but math operations are not defined on them. DV_SCORE might be an appropriate addition to openEHR. - thomas beale *
