A comparative study of automated blood pressure device and mercury-free LED blood pressure device using Lin's concordance correlation coefficient and other validity measures in Indian population

INTRODUCTION: Automated blood pressure (BP) monitor is widely used to assess the blood pressure (BP) of the study subjects in community-based researches. This study aims at the detection of hypertension by automated BP device and examines the concordance and validity between automated and mercury-free LED BP devices. MATERIALS AND METHODS: This cross-sectional study was conducted in the tribal state of Jharkhand in India from January 2017 to June 2017. A total of 300 study participants aged more than 18 years were enrolled in this study. BP of the patients in the sitting position was measured three times each by automated device and mercury-free LED BP device. The different sets of readings were assessed by concordance correlation coefficient (CCC) and other validity measures. RESULTS: The CCC for systolic and diastolic BP measured by automated and mercury-free LED BP is 0.88 and 0.85, respectively. The mean difference between systolic and diastolic BP by both the instruments is statistically insignificant (P > 0.05). The sensitivity, specificity, PPV, NPV, and accuracy of automated BP devices to predict hypertension is 96.61%, 92.21%, 75%, 99%, and 93%. The area under ROC for systolic and diastolic BP is 0.984 and 0.97, respectively with P values < 0.0001 in both the cases. CONCLUSIONS: This study concluded that the overall automated BP machine has fair degree of agreement (CCC) with a manual BP device. The validity of this monitor to screen hypertension may also be considered in field settings.