How can that be possible? 99.5% accuracy in knowing status? That's absurdly high, considering, just for a start, more than 0.5% of people have cognitive disord

How can that be possible? 99.5% accuracy in knowing status? That's absurdly high, considering, just for a start, more than 0.5% of people have cognitive disorders that would interfere with accurate surveying. And how many of those 3827 Internet study participants got tested?