Abstract
Cardiovascular diseases (CVD) are the leading cause of mortality globally. Hypertension is a known modifiable risk factor for CVD. Diagnosis and management of hypertension hinges upon accurate blood pressure (BP) measurement. In this study, we assessed performance to recommended guidelines for BP measurement in Rwanda. In 2017, a cross‐sectional study investigating performance on 11 techniques recommended for BP measurement was undertaken across outpatient settings of 3 departments at the University Teaching Hospital of Kigali, Rwanda. Performance was checked by an inside observer. The study enrolled 164 patients. The overall mean performance on the 11 BP measurement techniques was 5.69 (±1.02) out of the 11 possible points. There was no significant difference in performance across departments (P = .28). The findings suggest that performance on currently recommended guidelines for BP measurement is not optimal. Going forward, it is important to implement interventions that will enhance performance given that diagnosis and management of hypertension depend upon accurate BP measurement.
Keywords: blood pressure measurement, cardiovascular disease, hypertension, Rwanda
1. INTRODUCTION
Hypertension remains a significant risk factor for cardiovascular diseases (CVD), the leading cause of mortality globally.1, 2, 3 Over the last 3 decades, the number of uncontrolled hypertension cases has increased considerably and, in fact, it is projected to rise to 1.56 billion by 2025, with up to 68% of patients living in low‐ and middle‐income countries (LMICs).4, 5, 6 Globally, the prevalence of hypertension is approximately 40% for adults aged 25 years and over, with the highest rates in Africa (~ 46%) and lowest in high‐income countries (~ 35%).7 Although the prevalence of hypertension in Rwanda (a low‐income country in Africa) is not well known, a recent Rwandan study conducted on stroke management and outcome suggested that approximately 54% of patients diagnosed with stroke were hypertension treatment naïve, whereas 22% were unaware of having the disease.8
Diagnosing (and treating) hypertension hinges upon accurate arterial blood pressure (BP) measurement.9, 10 Accurate BP measurement plays a critical role in providing reliable data needed to guide policies and interventions.1 Although measuring BP is the most commonly performed medical procedure in clinical practice, BP determination is quite challenging given its physiological variability as well as the complexity of techniques and equipment used.11, 12, 13 Overdiagnosis of hypertension leads to a waste of resources and unnecessary submission of a patient to drug adverse effects and anxiety, whereas underdiagnosis results in a missed opportunity to prevent hypertension‐related diseases and complications.14
Several guidelines have been published that aim to improve accuracy (ie, absence of systematic error or bias) in BP measurement and standardized procedures and techniques have been established.9, 10, 11, 12, 13, 15, 16 Most of these recommendations set standards for patient preparation before BP measurement, position during measurement, and quality of the equipment to be used.9, 10, 11, 12, 13, 15, 16 Noncompliance with recommended BP measurement techniques can result in inaccurate BP measurement.13, 16 For example, measuring BP with cuff on clothing can change the BP by 10‐40 mm Hg, and stressful physiologic conditions such as having a full bladder can falsely elevate BP by as high as 15 mm Hg. Behaviors such as talking, using a cell phone, or inappropriate arm and leg positioning also can contribute to inaccurate momentary BP measurements.12
Prior studies that have investigated performance on BP measurement were conducted mainly in high‐income countries and have focused on evaluating performance among in‐training health care professionals.17, 18, 19, 20 We are not aware of any studies that assessed performance on BP measurement techniques in low‐income country settings. Therefore, the objective of this study was to assess performance on currently recommended international standards for BP measurement in outpatient settings of a tertiary‐level hospital in Rwanda.
2. METHODS
2.1. Study context
The Rwandan health care system is structured like a pyramid, with tertiary‐level hospitals sitting on top. The country has 4 tertiary‐level hospitals that provide outpatient and inpatient health care services to patients mainly referred from secondary‐level hospitals. These tertiary‐level hospitals are generally staffed by specialized medical doctors and nurses with university degrees. Rwanda has one of the fastest‐growing populations, the highest‐density population in Africa, and a low number of health care providers at the same time. The doctor/patient ratio and the nurse/patient ratio are 1/15428 and 1/1200 people respectively (http://www.moh.gov.rw/index.php?id=3). However, efforts are underway to increase the number of health care providers in Rwanda.21
2.2. Study population and design
From May to June 2017, we conducted a cross‐sectional study assessing performance or compliance to currently recommended international standards for BP measurement in outpatient settings of Kigali University Teaching Hospital (CHUK). Located in the capital city of Rwanda (Kigali), CHUK receives the largest number of patients of any hospital in the country. The study was conducted in outpatient settings of the Obstetrics & Gynecology (Ob‐Gyn), Internal Medicine (IM), and Surgery departments. Our study population included adult stable patients seeking outpatient medical care on appointment.
An ethical approval was obtained from the University Teaching Hospital of Kigali, Rwanda CHUK/Ethical Committee (EC/CHUK/364/2017).
2.3. Data collection and measures
While waiting for doctors' appointment at CHUK, patients usually get vital signs checked and recorded by a nurse. On average, 1 nurse takes care of approximately 23 patients on a typical outpatient day. As a requirement to work at tertiary‐level hospital, nurses must possess a university degree. As such, nurses whose performance/compliance on techniques for BP measurement was assessed were the same nurses working in outpatient settings and their main tasks include taking vital signs for outpatients.
Using a questionnaire that included 11 techniques recommended for BP measurement,9, 10, 17, 22, 23 a trained sixth‐year medical student (MD6) observed how blood pressure was being measured and recorded the findings. Observation was done on various occasions and the medical student observed various nurses in different offices in each of the 3 departments. The same medical student made the observations and collected all the data included in this study. The questionnaire explored nurses' skills centered around (1) patient preparation (patient not talking, get 5 minutes of rest, asked about smoking/coffee intake in the last 30 minutes or full bladder); (2) patient positioning (seated with back supported, feet resting on floor, legs uncrossed, arm supported, arm at heart level, measured at both arms); and (3) cuff selection and placement (arm bare and appropriate cuff size).
2.4. Statistical analysis
We used frequency (percentages) for categorical variables and means (standard deviations [SD]) for continuous variables to describe the study sample; Fisher exact test and 1‐way ANOVA were performed, as appropriate, to compare patients' characteristics across departments and nurses' performance on 11 BP measurement techniques across departments. We created a performance score using the 11 blood pressure measurement techniques and then used 1‐way ANOVA to compare performance scores across departments. Further, given that nurses could assess patients differently after learning about their history of hypertension, we constructed a multivariable linear regression model to investigate whether performance score was associated with patients' history of hypertension, adjusting for patients' sex, age, and BP medications. Statistical analyses were 2‐tailed and P values of < 5% were considered to show statistical significance. All statistical analyses were performed using R software, version 3.3.1.24
3. RESULTS
Table 1 provides characteristics of patients included in the current study. We collected data on 164 patients (mean age: 41 years), of whom 72% were female, 15% had reported history of hypertension, and 13% were on BP lowering medications. Ob‐Gyn outpatient clinics counted 37% of the patients whereas 31% and 32% were in IM and Surgery, respectively.
Table 1.
Characteristics of the study participants
| Characteristics | All (N = 164) | Ob‐Gyn (n = 61) | IM (n = 51) | Surgery (n = 52) | P value |
|---|---|---|---|---|---|
| Female, n (%) | 118 (72) | 61 (100) | 30 (59) | 27 (52) | < .001a |
| Age (years), mean ± SD | 41 ± 15 | 39 ± 12 | 47 ± 15 | 39 ± 16 | .005b |
| History of hypertension, n (%) | 24 (15) | 3 (5) | 18 (35) | 3 (6) | < .001a |
| On BP medications, n (%) | 22 (13) | 2 (3) | 17 (33) | 3 (6) | < .001a |
| Systolic BP (mm Hg), mean ± SD | 122.2 ± 18.4 | 119.7 ± 18.5 | 121.1 ± 20.6 | 126.2 ± 15.3 | .15b |
| Diastolic BP (mm Hg), mean ± SD | 77.5 ± 11.6 | 77.7 ± 11.9 | 78.1 ± 12.4 | 76.7 ± 10.6 | .80b |
BP, blood pressure; IM, Internal Medicine; Ob‐Gyn, Obstetrics and Gynecology; SD, standard deviation.
P value from Fisher exact test.
P value from 1‐way ANOVA.
The overall mean performance score on the 11 BP measurement techniques was 5.69 (±1.02) out of the 11 possible points (Table 2). There was no significant difference in performance across departments (Ob‐Gyn: 5.70 ± 1.13, IM: 5.90 ± 1.06 and Surgery: 5.48 ± 0.8, P = .28) (Table 2 and Figure 1). Of the 11 techniques assessed, only 6 techniques (“arm bare,” “appropriate cuff size,” “arm supported,” “legs uncrossed,” “patient not talking,” and “arm at heart level”) were assessed correctly in more than half of the patients (Table 2 and Figure 2).
Table 2.
Performance on each of the 11 techniques for BP measurement across departments, CHUK, 2017
| Parameter | All(N = 164) | Ob‐Gyn (n = 61) | IM(n = 51) | Surgery(n = 52) | P value |
|---|---|---|---|---|---|
| Patient not talking, n (%) | 122 (74) | 43 (70) | 31 (61) | 48 (92) | .001 |
| Get 5 min of rest in sitting position, n (%) | 39 (24) | 27 (44) | 1 (2) | 11 (21) | < .001 |
| Asked about smoking/coffee, in the last 30 min or full bladder, n (%) | 1 (1) | 0 (0) | 0 (0) | 1 (2) | .338 |
| Seated with back supported, n (%) | 54 (33) | 15 (25) | 8 (16) | 31 (60) | < .001 |
| Are the feet resting on the floor, n (%) | 64 (39) | 33 (54) | 30 (59) | 1 (2) | < .001 |
| Legs uncrossed, n (%) | 147 (90) | 57 (93) | 47 (92) | 43 (83) | .135 |
| Arm supported, n (%) | 156 (95) | 57 (93) | 50 (98) | 49 (94) | .498 |
| Arm at heart level, n (%) | 100 (61) | 17 (28) | 42 (82) | 41 (79) | < .001 |
| Measured at both arms, n (%) | 5 (3) | 3 (5) | 1 (2) | 1 (2) | .563 |
| Arm bare, n (%) | 164 (100) | 61 (100) | 51 (100) | 52 (100) | ‐ |
| Appropriate cuff size, n (%) | 162 (99) | 60 (98) | 51 (100) | 51 (98) | .627 |
| Mean performance(score out of 11) ± SD | 5.69 ± 1.02 | 5.70 ± 1.13 | 5.90 ± 1.06 | 5.48 ± 0.80 | .28a |
CHUK, University Teaching Hospital of Kigali ; Ob‐Gyn, Obstetrics and Gynecology; IM, Internal Medicine; SD, standard deviation; .
P values from Fisher exact test, except otherwise indicated.
1‐way ANOVA.
Figure 1.
Mean performance score (out of 11 possible points) by departments, CHUK, 2017. Ob‐Gyn, Obstetrics and Gynecology; IM, Internal Medicine; CHUK, University Teaching Hospital of Kigali
Figure 2.
Correct assessment on each of the 11 BP measurement techniques, CHUK, 2017. BP, blood pressure; CHUK, University Teaching Hospital of Kigali
The 5 remaining techniques were assessed poorly with correct assessment ranging from 1% to 39% (Table 2 and Figure 2): “Asked about smoking, coffee, food intake in the last 30 minutes or full bladder” (1%), “Get 5 minutes of rest in sitting position” (24%), “Seated with back supported” (33%), and “Are the feet resting on the floor” (39%). Of these 5 techniques, 2 techniques (“asking about smoking, coffee, food intake in the last 30 minutes or full bladder” and “measuring BP at both arms”) were assessed in only 1% and 3% respectively, and there was no difference across departments (P > .05) (Table 2). For the 3 remaining elements (“get 5 minutes of rest in sitting position,” “seated with back supported,” and “feet resting on the floor”) that scored below 50%, Ob‐Gyn did better than other departments for “get 5 minutes of rest in sitting position” (60%, P < .001). Surgery did better than other departments for “seated with back supported” (44%, P < .001), whereas Ob‐Gyn and IM did better than Surgery on “feet resting on the floor” technique (54% and 59% respectively, P < .001).
Comparing nurses' performance by patients' background, including history of hypertension, did not show any significant difference. The classic auscultation method was used in only 9 patients (5%) who were seen in outpatient clinics of the surgical department. The rest of patients' BP was measured using an automated blood pressure device.
4. DISCUSSION
The primary objective of this study was to assess techniques and performance on BP measurement techniques in Rwanda. Our findings suggest that performance on currently recommended techniques for BP measurement is not optimal at a tertiary‐level hospital in Rwanda. Moreover, performance did not significantly differ by the 3 departments we studied, nor did it vary by patients' background, including history of hypertension.
The performance across all departments in measuring BP was suboptimal, with an overall mean performance score of 5.69 out of 11 possible points we evaluated. The performance was slightly higher than what has been reported in previous studies evaluating in‐training health care providers in developed countries.17 There were striking variations on how the 11 elements/techniques were evaluated. In more than 90% of cases, the cuff was chosen appropriately and applied without clothing over the arm, the arm was supported and patients did not have legs crossed. On the other hand, most of the time patients did not get 5 minutes of rest (24%) before BP measurement, the positioning was poorly done with regards to resting feet (39%) and having the back supported (33%) and some of the time (25%) patients kept talking. Previous data have shown how tremendously such errors can affect BP accuracy.13, 16, 22 Intake of caffeine and/or smoking prior to BP measurement is another potential factor that can lead to falsely elevated BP. In our study cohort, only 1 patient was asked a question to rule out prior coffee/smoking, food intake, or other physiologically stressful condition such as having a full bladder. Although the importance of checking BP at both arms is emphasized in every clinical practice and is assumed to be known by every practicing nurse, only a small proportion of patients had their BP measured on both arms. Evidence suggests that a single BP reading is not sufficient to have accurate BP measures, which is vital to diagnosis/stage and treat/monitor hypertension.25
The poor performance on recommended BP measurement techniques raises concerns for potential errors in BP measurement, which could lead to misdiagnosis and or mismanagement of hypertension and, ultimately, affect not only population health outcomes related to CVD but also can result in inefficient use of scarce health care resources, as has been previously reported in other settings.26 For example, a study conducted in Swaziland revealed that 19.5% of patients were erroneously started on treatment for hypertension.26
Although the use of sphygmomanometer is still considered standard, the use of automatic devices is gaining more popularity, as it was used 95% of the time in this study. Use of sphygmomanometry and auscultation of Korotkoff sounds method requires supplemental equipment (stethoscope), more time, and further training for health care professionals, which makes it challenging to use in settings with low health care service provider density.13 In fact, the current study was conducted in a very busy clinic (CHUK), which is in accordance with a study by Kershenbaum and colleagues11 that concluded that the use of an automatic BP recording was the most practical way of achieving multiple readings in a busy clinic setting. Furthermore, the mercury sphygmomanometers are gradually falling out of favor not only because of technology advances but also environmental concerns.23
This study was conducted in a tertiary‐level hospital where the nursing staff is the most experienced and educated compared to the rest of health care facilities in Rwanda. It would be interesting to look at performance at lower‐level hospitals where a significant number of nurses have only a high school certificate although most of them are usually highly experienced. Although further studies should explore why recommended BP measurement techniques are not adhered to, we have attempted to provide some explanations based on our experiences working in Rwanda. One potential reason that can explain the observed suboptimal performance is the high patient volume at the studied hospital. This can explain the poor performance in procedures that require time and equipment such as measuring BP at both hands and resting a patient before measurement. However, other good practices such as asking about food/smoking/coffee intake and optimal positioning may not cost extra time, which can also raise concern about knowledge and awareness among the nursing personnel who usually take BP measurement. In routine clinical practice in Rwanda, medical doctors rely on vital signs taken by nurses and their performance on BP measurement is not known. Clearly, there is a need to emphasize on BP measurement techniques in health care professional education curriculum and also provide trainings to inservice health care professionals who are generally tasked with BP measurement.
Rwanda has made significant progress in fighting noncommunicable diseases (NCDs) by decentralizing NCD clinics to health center levels, but there are no existing national guidelines on BP measurement. This study is the first of its kind in Rwanda and will serve as reminder to clinicians to review the diagnostic process before initiation of treatment, which can result in a waste of resources or unnecessary harm and anxiety to patients in case of incorrect diagnosis. Despite its relevancy and timeliness, this study has a number of limitations that need to be acknowledged. This study was a single center cross‐sectional study conducted in a Rwandan tertiary‐level hospital staffed by nurses with advanced degrees, which makes it difficult to generalize the findings to lower‐level Rwandan health facilities including district hospitals and health centers where a substantial number of nurses only have a high school nursing certificate. Moreover, although the medical student pretended to be doing his routine clerkship (inside observer) and remained discrete while collecting data to minimize a potential Hawthorne effect, we cannot completely rule it out.
5. CONCLUSION
In conclusion, our findings suggest that compliance with currently recommended guidelines for BP measurement is not optimal in Rwanda. Further studies should explore reasons behind the unsatisfactory performance in BP measurement documented among the nursing personnel. Going forward, it is important to implement interventions that will enhance compliance given that diagnosis and management of hypertension depend upon accurate BP measurement. Given the importance of context, any proposed interventions should take local context into account including involvement of local health care providers.27
CONFLICT OF INTEREST
The authors declare no conflicts of interest to disclose.
AUTHOR CONTRIBUTIONS
JDK and CH conceived of and designed the study, performed the statistical analysis, contributed to the interpretation of data, and drafted the manuscript. JDK, ZN, and GB contributed to the acquisition of data. All authors reviewed the manuscript for important intellectual content and approved the manuscript for submission. JDK and CH are guarantors of the study.
ACKNOWLEDGMENTS
The authors gratefully acknowledge the comments of 3 anonymous reviewers. Dr. Hategeka is supported by Vanier Canada Graduate Scholarship from the Canadian Institutes of Health Research.
Kabakambira JD, Niyonsenga Z, Hategeka M, et al. Blood pressure measurement techniques: Assessing performance in outpatient settings of a tertiary‐level hospital in Rwanda. J Clin Hypertens. 2018;20:1067–1072. 10.1111/jch.13303
[Correction updated on May 28, 2018, after initial online publication: Affiliation of author Don Eliseo Lucero‐Prisno III has been updated from “Wuzhong, China” to “Suzhou, China.”]
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