A comparison of hospital and general practice blood pressure readings using a shared-care record card.

Shared-care blood pressure record cards were issued to 149 consecutive hypertensive patients attending our hospital clinic. In 108 (72.5 per cent), general practitioners entered readings they had obtained onto the cards. The use of the record card has proved helpful in the management of patients, and we are encouraged by the co-operation of the family doctors.A comparison of blood pressures measured in hospital and in general practice showed that general practitioners found systolic pressures to be an average of 5.5 mm Hg lower than hospital doctors, but there were no differences in diastolic pressure. In many cases, wide discrepancies were found both in hospital and general practice. We conclude that it is a myth that patients' blood pressures are lower when they consult their family doctor, or that outpatient blood pressure readings are falsely elevated by the stress of hospital attendance.