All the doctor's offices I've been in -- and I've seen a lot of doctors over the past year -- use the "old-fashioned" balance-beam scales. This is in the US, in New Orleans to be specific.

Drug dealers always use them, too, except that they're normally table-top units, not floor-standing medical-type scales including a device for measuring your height.

I always assumed that balance beam scales were unparalleled for accuracy.