[Diagnostic accuracy of blood pressure determination in clinics in control of hypertension: Proposal of new cut-off values]. / Precisión diagnóstica de la determinación de la presión arterial en consulta en el control del hipertenso: Propuesta de nuevos valores de corte.

AIM: This study seeks to determine the optimal cut-off values for the determination of the blood pressure in the clinic as a follow-up test in Primary Care practice. DESIGN: A total of 153 hypertensive patients under 80years of age who met inclusion and exclusion criteria for the study, were subjected to ambulatory monitoring of their blood pressure for 24hours (ABPM). After which two clinic-based measurements were obtained. With the results obtained from the clinic, and taking the ABMP as a reference, the ROC curve was calculated choose the optimal cut-off point. The agreement between both measurements was determined by the intraclass correlation coefficient and the Bland-Altman equation. A validation study was then carried out with the objective of diagnosing whether or not the hypertensive patient was in control. RESULTS: The optimal cut-off values were 137mmHg for systolic BP (sensitivity: 89.3%; specificity: 72.2%) and 84mmHg for diastolic blood pressure (sensitivity: 79.4%; specificity: 72.3%). The agreement in the diagnosis of control between clinic-based measurement and ABPM was 58.9% (Kappa: 0.418). CONCLUSION: The optimal cut-off value of the diastolic BP for follow-up is lower than the values currently established.