ABSTRACT
Measurement errors mean inaccurate decisions to put people on expensive, potentially uncomfortable, and occasionally dangerous medication which they do not need, or to ignore blood pressures that should be more actively treated. Home readings are of great help in identifying those who hyper-react to office measurements, however carefully these are made. These hyper-reactors are a small minority, but the gap between mean office and home measurements can be remarkable. Most medical and nursing students learn to measure blood pressures in antenatal clinics, the majority of which have frankly appalling traditions of measurement. Digit preference is the name applied to a clinical fact, that when asked to mark a descending target against a vertical scale of measurement marked at 2 mm intervals with unnumbered lines, and at 5 mm intervals with terminal 5s and 0s, observers prefer 0s to 5s, and 5s to even numbers.
