A study on hypertension and comparability between one reading and average of three readings of blood pressure by mercury sphygmomanometer among adults in a slum of Kolkata

Background: Hypertension, a major chronic lifestyle disease is most prevalent non communicable disease inIndia. Blood pressure (BP) measurements in the community are generally performed with a mercurysphygmomanometer. However, it is the common teaching that average of at least three readings of bloodpressure measurement is considered to be the gold-standard method. How far this is true has been determinedin this study with the Aim: To find out the prevalence of hypertension and compare the one reading of bloodpressure taken by mercury sphygmomanometer with average of three such readings. Materials andMethods:This cross-sectional study was conducted from January-March 2015 among 160 adults of Chetla slum, Kolkatachosen through a two stage sample design. ubjects included -Male: 39.4%; Female: 60.6%. Data was collectedby interview and blood pressure measurements. Comparison was made between the first reading and theaverage of three readings of BP taken by mercury sphygmomanometer. Result: The overall prevalence ofhypertension was found to be 30 % (48). Strength of agreement between first reading of Blood Pressure with thatof average reading was excellent, with kappa=0.940. Conclusion: Though the average of three blood pressurereadings according to Standard operation Procedure is considered ideal for accurate Blood Pressuremeasurement it may not always be feasible to undertake such a practice especially at community level. Thisstudy observes that single reading can safely be considered for Blood Pressure measurement instead of averageof three readings. Key words: Blood Pressure measurement, One reading, Average of three readings, Mercury sphygmomanometer, Slum.