Objective: To compare the standard procedure (SP) for determining hypertension as described by the DCGP with the results of ambulatory blood pressure measurement (ABM).
Design: Prospective study.
Setting: Practices of 17 GPs in central and south Limburg, the Netherlands.
Method: The SP of the DCGP was executed in 94 of 102 patients with possible hypertension. In each patient a 24-hour ABM was performed simultaneously as reference value.
Results: The correlation between the SP and the ABM was low (r = 0.51) and the blood pressure was mostly overestimated by the SP. Sensitivity and specificity of the SP were 0.67 and 0.52 respectively. When the first blood pressure measurement was high in a patient with probable hypertension (diastolic pressure 105-115 mmHg) SP correlated well with ABM. When the first blood pressure measured was relatively low (diastolic pressure 95-105 mmHg) correlation was also low.
Conclusion: The difference in blood pressure measured by the physician in his office compared with measurement at home ('white coat effect') was observed in this study also. The results support the advice of the DCGP to check the blood pressure more often in hypertensive patients with low than in those with high initial diastolic values.