Clinical Skills Training: Do Medical Students Have Enough Knowledge of Accurate Blood Pressure Measurement When They Graduate*

Objective: Accurate blood pressure measurement is critical for diagnosing and treating hypertension. Our study investigated the medical faculty students’ adherence to international blood pressure measurement recommendations. Methods: Three hundred fifteen final-year medical students from University and due to graduate in 2021 and 2022 were included in the study. These were asked 21 questions evaluating the different blood pressure measurement steps. The responses were then compared with the guideline recommendations. Results: Of the students, 55.2% were women and 65.7% were 2021 graduates. The majority (69.2%) of the students preferred aneroid devices, while 19.7% selected mercury devices for measurement, and 47.6% paid attention to calibration and validation during device selection. Most participants (92.1%) reported taking measurements sitting, with the back supported and the legs uncrossed. While 62.9% measured blood pressure from both arms at the initial visit, only 37.8% investigated all affecting factors before measurement. Seventy-four percent of the students answered the cuff deflation rate correctly. Approximately half (55.2%) recorded the measured values by rounding them up or down to the nearest even number. Although more than 50% of students answered most of the questions in line with the guidelines, only 1 student completed all the steps appropriately. Conclusion: The results of this study showed that students did not fully comply with the measurement recommendations. Considering the importance of accurate blood pressure measurement to public health, it would be beneficial to reorganize the medical education curriculum and repeat it regularly.


INTRODUCTION
Hypertension is a common public health problem; about one-third of adults worldwide are hypertensive.It is the leading modifiable risk factor for mortality and accounted for 10.8 million deaths in 2019. 1 Lowering blood pressure (BP) reduces morbidity and mortality among various baseline BP levels and comorbidities.Recently, large meta-analyses showed that 5-and 10-mm Hg reduction in systolic BP reduced the risk of major cardiovascular events by about 10% and all-cause mortality by 13%. 2,3though home BP measurement and ambulatory BP measurement have recently been described as potentially more accurate in diagnosing hypertension, office blood pressure measurement (OBPM) is still valid and widely employed.
Accurate measurement of BP is essential in the diagnosis and follow-up of hypertensive patients.However, 29 potential sources of inaccuracy in BP measurement have been identified and categorized as either patient, device, procedure, or observer related. 4Inaccurate BP measurement can lead to significantly incorrect assessments (under-diagnosis or over-diagnosis of hypertension), which may result in inadequate or unnecessary treatment.Therefore, it is essential to determine whether all healthcare professionals, especially doctors and nurses, accurately measure BP.
This study aimed to determine the BP measurement attitudes of medical students and their level of knowledge concerning accurate BP measurement.

Study Population and the Survey
Final-year medical students (known as "intern physicians" in Türkiye) from the Ondokuz Mayıs University Faculty of Medicine in the academic years 2020-2021 and 2021-2022 were included in this study.The study was approved by the Ondokuz Mayıs University Clinical Research Ethics Committee (date: August 18, 2021; protocol number OMU 2021/128) and was conducted under the principles of the Declaration of Helsinki.Twenty-one questions concerning accurate BP measurement were put to the participants through an online structured survey.The questions were produced based on the information contained in the current recommendations for accurate BP measurement.Written informed consent was obtained from the students who participated in this study.
The survey consisted of 4 parts (Table 1).The first questions were about the devices the participants preferred for BP measurement and the factors involved in device selection.The second investigated patient-related factors affecting BP measurement.Participants selected the factors affecting BP from multiple options.The potential options included resting, smoking, or drinking alcohol, using caffeine, whether the bladder is empty, and the patient's arm being completely free of clothing.The third part contained questions concerning procedure-related factors.These were intended to determine the position in which the patient's BP is measured, whether the patient rested before the measurement, and what the patient's back, leg, and arm positions were during the measurement.Questions about the cuff included factors affecting the cuff size selection, its place in the measurement, inflation, and deflation rates.Participants indicated which arm they used to measure BP at the initial visit and the time interval between multiple measurements.The final part determined how the participants recorded the BP values as an observer-related factor.

Statistical Analyses
Descriptive statistics were used throughout the study, and the variables were presented as numbers and percentages.Chisquare tests were used to evaluate students' attitudes during BP measurement according to their anticipated years of graduation.Statistical significance was set at P < .05.Data entry and statistical analysis were performed on IBM Statistical Package for the Social Sciences Statistics for Windows version 25 software (IBM SPSS Corp.; Armonk, NY, USA).

RESULTS
Three hundred and fifteen students participated in the study.The majority were women (55.2%) and expected to graduate in 2021 (65.7%).The participants' mean age was 24.83 ± 1.96 years.The answers given to the survey questions are shown in the Table-1.
Analysis revealed that 69.2% of the participants reported measuring or preferring to measure BP using an aneroid device.While automated devices were the least popular option (11.2%), 19.7% of the participants preferred mercury sphygmomanometers.Asked what factors should be considered when selecting a sphygmomanometer, 47.6% of students were interested in the device's calibration and validation, although 36 (11.4%) paid no attention to both.
Asked which conditions they checked before BP measurement, only 119 (37.8%) participants took into account all the relevant factors (empty bladder, quiet room, comfortable temperature, and avoiding caffeine, exercise, smoking, and alcohol use) set out in the guidelines.Two hundred twenty-five participants (71.4%) reported requiring their patients to rest for at least 5 minutes, while 11 (3.5%) measured BP with no such rest.Asked which position they prefer for BP measurement, all but 3 (0.9%) reported measuring BP with the patient in a sitting position.The majority (92.1%) also ensured that the patient's back should be supported and the legs uncrossed, as stated in the guidelines.
Regarding arm position, more than half (56.8%) of the students responded that "the arm should be supported and at heart level."The correct arm position in a standing or prone position was known by 72.4% and 78.4% of the participants, respectively.Asked how they selected the cuff size, 42 (13.4%)participants paid no attention to the arm circumference.Two hundred fortytwo (76.8%) participants answered "2-3 cm above the antecubital fossa" for the placement of the cuff on the arm, and 63 (20%) responded "5-6 cm above the antecubital fossa."Approximately three-quarters of the participants (76.2% and 74%, respectively) stated that they inflated the cuff to 30-40 mm Hg above

MAIN POINTS
• Accurate blood pressure measurement is essential for diagnosing hypertension.• Inaccurate blood pressure measurement can lead to incorrect hypertension classification.• Medical students show poor compliance with recommendations for blood pressure measurement guidelines.• When the blood pressure measurement steps were examined separately, more than half of the participants generally used these as described in the guidelines.However, only 1 student answered all the questions correctly.This study evaluated medical students' approaches to BP measurement and their levels of knowledge about accurate BP measurement as well as the effect of the COVID-19 pandemic face-to-face education restrictions.
The students exhibited low compliance with the BP measurement methods recommended in the guidelines.When we examined the BP measurement steps separately, more than half of the participants generally applied these as described in the guidelines.However, only 1 student answered all the questions correctly.
Diagnosis of hypertension requires accurate BP measurement.Although the guidelines recommend using automated devices for OBPM, most participants (69.2%) in the present study preferred aneroid devices for OBPM.Automatic devices were less popular (10%).Aneroid devices may result in measurement errors, although regularly calibrated devices can be used safely. 5,6The fact that our university medical students are mostly trained with aneroid devices may have affected the device selection.Aneroid devices are also frequently used in daily practice.Similarly, a recently published study from Türkiye reported that primary care physicians most frequently use aneroid devices, while automated devices are least often employed in daily practice. 7lecting inappropriate devices is one of the common errors in BP measurement.The importance of validation and calibration of devices is discussed in almost all BP diagnosis and treatment guidelines. 8,9Uncalibrated devices cause inaccurate BP readings. 10Akpolat et al 11 reported a higher frequency of accurate devices among validated than in non-validated sphygmomanometers and that online websites where validation status can be checked are easily available. 9Half of the participants in the present study paid attention to validation and calibration, while approximately 10% disregarded these.
Proper maintenance and routine calibration of BP equipment are crucial to the accuracy of BP readings. 12A study of physician practices in Switzerland reported that 97% of devices had not been calibrated for at least 2 years.More importantly, the number of sphygmomanometers with measurement errors increased significantly 2 years after maintenance. 13ss than half of the medical students in this study investigated all factors capable of affecting BP before taking measurements, and three-quarters reported that the patient should rest for at least 5 minutes.In a study involving 103 fourth-year medical students in Iran, only a few (13.6-50.5%)participants discussed the situation with the patient before measurement, and only 31.1% required the patient to rest for 5 minutes. 146][17] However, some parameters, such as bladder distension, are frequently entirely forgotten. 18n other studies, most medical students (54%-86.3%)5][16] The awareness rate in the present research was higher than that in a study largely composed of cardiologists 19 but lower than that observed among family physicians in Türkiye. 7st of the students in this study knew that BP measurement should be performed with the patient in a sitting position, that the patient's back should be supported, and that the legs should not be crossed.Studies have shown that a non-optimal arm position during BP measurement results in higher systolic and diastolic BP values, 20 and the guidelines recommend supporting the arm during measurement to obtain correct BP values. 8,9owever, only half of the medical students possessed accurate information concerning arm position in this study.
Cuff size selection is another critical step that affects BP measurement.The inflatable bladder of the cuff must cover 75%-100% of the individual's arm circumference.However, 13.4 % of the participants in this study disregarded the cuff size.While results similar to those of this study have been reported, 16 some studies have reported that medical students attach no importance to the selection of cuff length. 15,16Three-quarters of the students in this research gave answers compatible with the guidelines concerning arm cuffing, inflation point, and inflation rate.These factors are well known to affect accurate BP measurement.
All guidelines 8,9 recommend recording BP measurements rounded to the nearest even number.However, despite an improvement in recent years, 40% of BP measurements in the USA are rounded to zero. 21The incidence of a final digit of zero for BP is approximately 35% in both Canada and the UK. 22A similar rate of 35% was observed in this study.However, only 21.4% of primary care physicians in Türkiye are reported to record measurements to the nearest even number. 7Gozdecki et al 23 showed that standardized oscillatory BP measurement implementation reduced the terminal digit preference.
Administration of Automated office blood pressure (AOBP) has also been associated with decreased end-digit preference levels in clinical practice. 22proximately two-thirds of the participants measured BP from both arms at the first visit and took at least 2 measurements.Only 18.4% cited an interval between measurements of 1-3 minutes, the most common being 5-10 minutes.However, these measurement errors are also quite common in clinical practice. 7,19re than half of the students provided answers in accordance with the guidelines for each question concerning the steps involved in BP measurement in this study.However, only 1 answered all the questions correctly.While this is somewhat surprising, Rakotz et al 17 also reported that only 1 out of 159 medical students demonstrated proficiency in all BP skills.The students' performances in that study were generally poor.In a well-designed study, Ulusoy et al 24 observed that physicians did not fully comply with guideline recommendations and had many errors during BP measurement.But even more strikingly, they reported 39 (46.4%) out of the 84 physicians never measured BP during patient examinations.The researchers determined that 18.9% of patients whose BP was not measured were hypertensive.
The COVID-19 pandemic also affected medical education.
Although most of the results in this study were not affected by face-to-face or online education, differences were observed in 3 different steps.Some studies have suggested that online education was sufficient during the pandemic. 25Similarly, although their data showed that simulation-based BP measurement training also yields successful results 26 , Basheer et al 27 reported that medical students who trained on their colleagues (conventional training) exhibited a higher rate of accurate BP recording than those who received simulation-based training.Skill development is generally reinforced by training, practice, and repetition.Accurate BP measurement rates among medical students improve with training, and increasing the duration and intensity of education improves proper BP measurement skills. 28is study has several limitations.First, this research was a survey study.The participants' responses do not reflect the general population and may cause bias.The answers given to surveys and approaches to measurement may not reflect the situation in clinical practice.In addition, it is impossible to establish a causeeffect relationship in survey studies.However, surveys should be carried out intermittently to evaluate knowledge levels and rearrange training accordingly.A particular strength of this study is that it included many medical students who would soon be involved in diagnosing and treating real-life hypertension.
The results of this study indicate that compliance with appropriate BP measurement techniques among medical students is low.Reviewing and adjusting the curriculum and intensifying and repeating training at regular intervals may increase the rate of accurate BP measurement.

Table 1 .
The Students' Answers to Questions Concerning Accurate Blood Pressure Measurement the level at which the radial pulse disappeared and deflated it at a rate of 2-3 mmHg/s.Asked how they recorded the measurements, 174 (55.2%) participants recorded them to the nearest even number, while 110 (34.9%) rounded them up or down to 0-or 5-mm Hg.One hundred ninety-eight (62.9%) participants emphasized the importance of taking measurements from both arms at the initial visit.One hundred one (32.1%)studentsreportedtaking 1 measurement during the initial evaluation, 203 (64.4%) reported 2, and only 11 (3.5%) reported 3 or more.In addition, 18.4% of the participants reported taking measurements at 1to 3-minute intervals and 57.1% at 5-to 10-minute intervals.More than 50% of the students answered most questions correctly (Table1).However, only 1 correctly answered all the

Table 1 .
The Students' Answers to Questions Concerning Accurate Blood Pressure Measurement (Continued)