Blood pressure Mercury sphygmomanometer quality control

Based on EHES Manual, Part B. Fieldwork procedures, 2nd edition, 2016 Available at: http://urn.fi/URN:ISBN:978-952-302-701-5 These slides can be used freely, translated and adapted to national use (e.g. concerning the equipment and fieldwork organization).

Quality assurance of blood pressure measurements Each person measuring blood pressure has to pass a hearing test Adequate training: theory and practice Understanding the difference between clinical practice and survey fieldwork Competence and commitment to follow protocols carefully Checking the equipment Auditing Adherence to the protocol Evaluation of data during the fieldwork

Theoretical and practical training Theory providing information about Why it is important to measure blood pressure Why blood pressure measurements need to be standardized What implications differences in the protocol have to the blood pressure levels Practice with several different persons with a wide range of blood pressure levels Supervision and feedback At the end, testing the levels: agreement with an experienced measurer

Checking the equipment and regular calibration Protocols for daily and weekly equipment checks recorded in a log book Calibration of used devices before starting of the fieldwork If fieldwork lasts longer than a year or the number of daily measurements is high, re-calibration may be needed in between

Audit visits Regular audit visits and observations to ensure that protocol is followed correctly Adherence to the standard protocol evaluated

Data evaluation during the fieldwork Data on blood pressure measurements should be checked regularly for Missing data and recorded reasons for that Mean and standard deviation of systolic and diastolic measurements Identical measurements and difference between first, second and third measurements Terminal digit preference Separately for each measurer (nurse)

Missing data and reasons for that If blood pressure cannot be measured, a reason for that should be recorded Frequency by measurer E.g. if some measurer has a lot of missing information and refusals for the measurement, this may reveal that she/he is not properly introducing the measurement for the participants

Mean and standard deviation Calculated by measurer, separately for systolic and diastolic measurements Identifies if some measurers are producing readings systematically lower or higher than the team average , e.g. due to their actions

Difference between subsequent measurements Calculated by measurer, separately for two subsequent systolic and diastolic measurements Identifies possible problems with measurements and recording errors

Terminal digit preference Distribution of terminal digits for systolic and diastolic measurements separately by measurer Reveals if some measurers have a preference for some digit (for example zero) use odd digits which should not be used according to the protocol

Identical measurements Proportion of identical subsequent measurements for the same participant, separately for systolic and diastolic measurements, by measurer Helps to determine that all 3 measurements are correctly done for all participants

Acknowledgement Slides prepared by: Hanna Tolonen, Päivikki Koponen Experiences and feedback from the EHES network have been utilized in the preparation of these slides Funding: Preparation of the slides is part of the activities of the EHES Coordinating Centre which has received funding from the EC/DG SANTÉ in 2009-2012 through SANCO/2008/C2/02-SI2.538318 EHES and Grand Agreement number 2009-23-01, and in 2015-2017 through Grand Agreement number 664691/BRIDGE Health

Disclaimer The views expressed here are those of the authors and they do not represent the Commission’s official position.