Reading around (e.g. [0]) it sounds like variance isn't something researchers care for, probably with the assumption that screening with a higher value is better than missing an issue from a lower value.
We see the same for body temperature (speed and convenience is usually prioritized over accuracy) and weight (2% variation is largely accepted). Afterall guidelines are already off as by definition, as they don't account for individual circumstances, so perhaps aiming for accuracy is useless in most settings.
We see the same for body temperature (speed and convenience is usually prioritized over accuracy) and weight (2% variation is largely accepted). Afterall guidelines are already off as by definition, as they don't account for individual circumstances, so perhaps aiming for accuracy is useless in most settings.
[0] https://www.mayoclinic.org/diseases-conditions/high-blood-pr...