ABSTRACT
BACKGROUND: Non-invasive blood pressure (BP) devices should be independently evaluated before being used in special populations. The objective of this study was to assess the accuracy of the Welch-Allyn transtelephonic home blood pressure monitor in adults with Parkinson's disease to evaluate the device for use in a large clinical trial involving the safety and efficacy of a monoamine oxidase inhibitor. METHODS: BP measurements taken with the device were compared with the results obtained by two experienced observers using a mercury sphygmomanometer in patients with Parkinson's disease. The limits of agreement were then calculated for the device and compared with the results of the two observers. RESULTS: The agreement parameters between the two observers were -0.5 +/- 2.6 mmHg for systolic BP and 0.1 +/- 2.2 mmHg for diastolic BP. The agreement between the Welch-Allyn transtelephonic device and the observers was -2.6 +/- 4.5 mmHg and -1.9 +/- 3.2 mmHg for systolic and diastolic BP respectively. Nearly 90% of the readings were within 10 mmHg of the observers for both systolic and diastolic BP. Mild tremor had a moderate effect on the validity of the device. CONCLUSIONS: The Welch-Allyn transtelephonic device demonstrated acceptable precision in this cohort of patients with Parkinson's disease and is considered valid for use in a clinical trial involving these patients.
