Are aneroid and digital sphygmomanometers as reliable and accurate as mercury sphygmomanometers?

Abstract

Background: The accurate measurement of blood pressure (BP) is crucial for effectively treating hypertension, which stands as a primary risk factor for both cardiovascular disease and premature mortality. The shift from mercury to nonmercury sphygmomanometers in developing countries due to environmental concerns prompts an evaluation of the accuracy of these alternatives. Aims and Objectives: The objectives of this study were to evaluate the precision of non-mercury instruments in diagnosing hypertension and to analyze interarm differences in both systolic and diastolic BP using three different sphygmomanometers. Materials and Methods: Sixty subjects aged 18–25 were included. BP measurements were taken from both arms using different types of sphygmomanometers. Statistical analysis involved paired t-tests, Chi-square tests for correlations, and a significance threshold of P < 0.05. Results: Significant differences in systolic BP readings were observed between the gold standard (mercury manometer) and digital/aneroid devices (P = 0.00). Compared to the mercury manometer, both digital and aneroid devices showed limited accuracy in detecting hypertension. Kappa agreement was moderate at 0.57. Despite high specificity (100%), sensitivity was lower at 44.4%, indicating a risk of missing true positive cases. Both devices exhibited a sensitivity of 25%, with fair to poor agreement (kappa values) in identifying cardiovascular risk compared to the mercury reference. Conclusion: This study underscores the diminished reliability of both aneroid and digital devices in detecting hypertension and assessing cardiovascular risk using specified interarm BP criteria. These findings emphasize the crucial need for further research and caution when relying on non-mercury devices in clinical settings.