Comparison of wrist blood pressure measurement with conventional sphygmomanometry at a cardiology outpatient clinic

Objective Oscillometric measurement of blood pressure at the wrist is becom ing a widely used method for detection of hypertension and its control by t reatment. The objective of the present study was to evaluate accuracy and s uitability of wrist measurement in a clinical routine setting. Patients and methods A series of 333 consecutive patients admitted to our c ardiology outpatient clinic were included. Blood pressure was measured at b oth upper arms according to World Health Organization-International Society of Hypertension guidelines. Oscillometric measurement was performed at the contralateral wrist simultaneously. Blood pressure readings were taken by an oscillometric device applied at the wrist ('Klock'; Industrielle Entwick lung Medizintechnik, Stolberg, Germany) and a conventional mercury sphygmom anometer applied at the upper arm. Results Seventy-eight patients were excluded due to differences in blood pr essure > 5 mmHg between both upper arms or due to 'error' messages of the w rist device. The data of the remaining 255 patients (149 males; mean age, 6 5 +/- 13 years; range, 18-95 years) are presented. Mean conventional blood pressure was significantly lower compared with the wrist device (137 +/- 20 /80 +/- 11 mmHg versus 153 +/- 28/87 +/- 18 mmHg; P < 0.001 and P < 0.001). The mean difference was 16 +/- 25/ 6 +/- 17 mmHg. In clinical terms, diffe rences in blood pressure exceeding +/-20/+/-10 mmHg reflecting classificati on of hypertension are considered important. Measurements of 101 (40%) pati ents were within these limits. Systolic readings of 110 (43%)and diastolic readings of 117 patients (46%) were beyond this scope. Conclusion Due to low reliability of wrist blood pressure measurement, it c annot compete with the upper arm standard procedure. If ever, it should onl y be used if test readings in an individual comparing wrist and upper arm m easurement show differences within a range of +/-20/ +/-10 mmHg. J Hyperten s 2000, 18:1013-1018 (C) Lippincott Williams & Wilkins.