Abstract

Hypertension is one of the major public health problems affecting the whole world and has been identified as the most common communicable disease in Nigeria. Accurate measurement of blood pressure is of utmost importance for early diagnosis and management. Concerns related to the potential ill effects of mercury on health and environment have led to the call for the removal of mercury sphygmomanometers from clinical investigations, and the widespread use of non-mercury sphygmomanometers. However, the accuracy of these non-mercury measures needs to be ascertained. This study was conducted to compare the accuracy of aneroid and digital sphygmomanometers with reference to a mercury sphygmomanometer. A total of 72 subjects (34 males and 38 females) were used for this study. All the subjects were between the ages of 20-25 years and weighed between 52kg-80kg. Three blood pressure (BP) readings were taken from each arm using each sphygmomanometer type, and the means of these readings were recorded. Paired t-test and independent t-test were used to analyze the data and values of p < 0.05 were considered statistically significant. The results showed that the males had significantly higher systolic and diastolic BPs than the females. The males also had higher inter-arm differences than the females, which was significant only with the mercury sphygmomanometer. Absolute systolic inter-arm difference ≥10mmHg and diastolic inter arm difference ≥ 5mmHg were considered the risk factors of future cardiovascular morbidities. Therefore, the inter-arm difference should be considered during blood pressure measurement for the correct management of hypertension. The results also showed significant differences between the mercury and Aneroid measures, and also between the mercury and digital measures. However, these variations were within the threshold set by the Association for the Advancement of Medical Instrumentation guidelines, with the exception of the diastolic pressures measured by the digital instrument, which were lower than the mercury measures. This means that both non-mercury instruments can serve as independent instruments for accurate blood pressure measurement in clinical and research settings.