Barriers to Screening and Intervention for ED Patients at Risk For Undiagnosed or Uncontrolled Hypertension

Article Outline

• Abstract
• Methods
  • Study Design
  • Study Setting and Population
  • Study Protocol
• Measurements
  • Statistical Analysis
• Results
• Discussion
  • Limitations
• Implications for Emergency Nurses
• Conclusion
• Acknowledgments
• References
• Biography
• Copyright

Objectives

We describe clinician-reported knowledge of the Joint National Committee (JNC7) on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure definitions of Stage I hypertension; perceived causes of elevated blood pressure; barriers to blood pressure re-assessment; risk of adverse events associated with the elevated blood pressure.

Methods

Health care providers from five emergency departments completed a questionnaire assessing knowledge of blood pressure criteria for hypertension, perceived causes of elevated blood pressures, barriers to re-assessment, and perceived risk of an adverse event at one year in a patient within three defined systolic and diastolic blood pressure ranges. Descriptive statistics were used to analyze the data.

Results

Seventy-two percent (379/524) of providers (68 attending physicians, 87 residents, 209 nurses, and 15 nurse practitioners) completed questionnaires. One hundred and four providers (27%) correctly listed the systolic and diastolic criteria for Stage 1 hypertension. Nurses and physicians rated uncontrolled, known hypertension [mean (standard deviation)] [8.7 (2.1), 8.9 (1.9)] the highest and pain [8.3 (2.3), 8.3 (2.1)] as the second highest cause of elevated BP. Nurses and physicians rated the lack of time to perform a reassessment [5.2 (3.4), 4.7 (2.8)] and a lack of adequate staffing [4.7 (3.4), 4.6 (2.9)] the highest as barriers to re-assessment. Nurses' mean adverse risk assessment twice that of physicians.

Discussion

Twenty seven percent of providers were aware of the JNC7 criteria and often attributed elevated blood pressures to chronic, uncontrolled hypertension, pain or anxiety. No single barrier to repeating elevated blood pressures was identified.

Key words: Hypertension, Public health, Blood pressure, Emergency department, Screening, Referral

The crisis in health care in the United States demands a dramatic shift from treatment to the prevention of chronic diseases. In 2002, 93% of health care spending for Medicare beneficiaries was incurred by persons with 3 or more chronic health conditions, of which hypertension is a very common chronic disease.¹ In 2005, cardiovascular disease and stroke were the number 1 and number 3 leading causes of death, respectively.² Uncontrolled hypertension significantly contributes to both of these diseases, with an estimated direct and indirect cost for 2009 of 73.4 billion dollars.² If blood pressure control were achieved at the recommended thresholds of <140/90 mm Hg for non-diabetic persons and <130/80 mm Hg for persons with diabetes, it is estimated that this achievement could result in a 15% reduction in the number of myocardial infarctions and a 21% reduction in strokes.³ The earlier that hypertension is identified and treatment is initiated, the more health care dollars and lives can be saved.

Emergency departments are uniquely positioned to assist in screening efforts in that they have the potential to identify both “newly diagnosed” as well as poorly controlled hypertensive patients. In 2000, the Society for Academic Emergency Medicine Public Health and Education Task Force Preventive Services Work Group recommended routine screening for hypertension, providing sufficient resources were available.⁴ In 2006 the American College of Emergency Physicians (ACEP) recommended that ED patients with persistently elevated blood pressures receive a referral intervention for follow-up of possible hypertension.⁵ While “persistently elevated blood pressure” was not explicitly defined in this policy recommendation, clinical practice suggests that emergency clinicians would not refer a patient for follow-up and evaluation of possible undiagnosed hypertension based on an isolated elevated blood pressure reading. Thus, blood pressure re-assessment is a critical step in determining the need for referral. Despite these recommendations, the routine performance of screening, brief intervention, and referral for treatment for patients with elevated blood pressure, when unrelated to the reason for the visit, remains controversial.⁶, ⁷, ⁸

To better understand why the compliance with the aforementioned recommendations remains low, it is important to determine whether there is a knowledge deficit with respect to blood pressure thresholds or if other barriers to blood pressure re-assessments exist. Therefore, the aim of this investigation was to determine: (1) clinicians' knowledge of the Joint National Committee 7 (JNC7) definitions of stage I hypertension, (2) clinicians' perceived causes of elevated blood pressure, (3) barriers to blood pressure re-assessment, (4) risk of adverse events associated with the elevated blood pressure, and (5) medico-legal implications of not advising patients of their elevated blood pressure.

Back to Article Outline

Methods 

Study Design 

This investigation was a sub-study of a larger, prospective multicenter investigation comparing health care provider self-report with actual practices.⁹ For this portion of the study, health care providers were asked to complete a questionnaire on elevated blood pressure in ED patients. Institutional Review Board approval was obtained at all 5 sites. Questionnaires included a cover sheet describing the study and informing potential subjects that participation was completely voluntary. Implied consent was acknowledged in the receipt of a completed, anonymous questionnaire.

Study Setting and Population 

This study was conducted over a 6-month period, with the last site completing all data collection in June 2006. Five emergency departments participated; 4 were urban, academic centers, and 1 was a suburban center. The annual census at each site ranged between 49,000 and 120,000. The suburban center had no residents participating in patient care. Nurse practitioners functioned as physician extenders in 2 of the academic centers and also at the suburban center. All nurses, nurse practitioners, physician emergency medicine residents, and attending physicians were invited to participate in this investigation. Health care providers were excluded from participation if they were not present (eg, on personal leave, on sabbatical, or participating in an off-site elective) during the data collection period. In addition, residents rotating in the emergency department from other services did not complete questionnaires. These criteria left 312 nurses, 99 residents, 97 attending physicians, and 16 nurse practitioners (n = 524) eligible to participate in this investigation.

Study Protocol 

Health care provider questionnaires were distributed to providers at each site after the chart abstraction for the primary study was completed. Providers were asked to complete the questionnaires within 7 days of receipt. Providers were given only one reminder to return completed questionnaires approximately 1 week after the original distribution. Additional reminders were not undertaken to avoid any sense of coercion, particularly of residents.

Back to Article Outline

Measurements 

A standardized questionnaire was developed based on the literature. Face validity was established by a review of several emergency medicine physicians with expertise in the area of hypertension. The survey also was reviewed by several emergency nursing experts. Several revisions in the survey were made prior to finalization. The survey included a section on demographic data, thresholds for re-assessment, potential causes of elevated blood pressure, barriers to blood pressure re-assessment, and an assessment of adverse risk at 1 year. Demographic information was solicited from all providers, including sex, professional degree, and years of practice. For physicians, board certification also was noted, because some attending physicians were board certified in more than one specialty. Residents were asked to list their total years of residency training.

Provider knowledge of blood pressure criteria for stage I hypertension (Table 1) was assessed using the open-ended question, “What are the Joint National Committee (JNC7) guidelines on hypertension?”¹⁰ Knowledge of stage I versus stage II hypertension was assessed because awareness of the lower blood pressure threshold represents a larger public health opportunity. The response to this item was considered correct if both the systolic and diastolic blood pressure measurements were correctly noted.

Table 1. Definitions of the Joint National Committee and guidelines on hypertension

Providers also were asked to rate the potential causes of elevated blood pressure in ED patients. In previous literature, pain, anxiety, and inaccurate readings have been cited as causes for elevated blood pressure in presenting ED patients.⁵ To further characterize these and other items as perceived factors, providers were asked to rate 7 items as potential causes of elevated blood pressure. Using a 10-point Likert-type scale, with 1 = not a common cause and 10 = a very common cause, providers rated the following items: pain; uncontrolled, known hypertension; anxiety; substance abuse; undiagnosed hypertension; inaccurate reading; and inaccurate blood pressure cuff size. An “other” response was included to allow providers to identify additional perceived causes of elevated blood pressure measurements.

Providers also were asked to rate the barriers to performing a repeat blood pressure measurement using the same 10-point Likert-type scale, where 1 = not a barrier and 10 = a very important barrier. The following 5 items were rated by health care providers: elevated blood pressure is not a priority; lack of adequate staffing; lack of time to re-assess; additional elevated readings will not alter my treatment; and ED blood pressure readings are inaccurate. An “other” response was included to allow providers to identify additional barriers to repeating a blood pressure reading.

Providers were asked to note their perceived risk of an adverse event at 1 year in a patient within 3 defined systolic and diastolic blood pressure ranges. An adverse event was defined as a myocardial infarction, cerebral vascular accident, or death. The systolic and diastolic blood pressure ranges provided were those used by JNC7 to define pre-hypertension, stage I hypertension, and stage II hypertension. Responses ranged from 0% = no risk to 100% = very high risk. Finally, providers were asked to rate medico-legal implications of not advising patients of their elevated blood pressure. Health-care providers used a 10-point Likert scale, with 1 denoting the lowest liability and 10 the highest liability.

Statistical Analysis 

Descriptive statistics were used to describe sample characteristics, and continuous variables were presented as means with standard deviations (SDs) are reported per provider type. The Student t test was used to compare continuous variables, and Fisher's Exact test or the χ² statistic were used to compare categorical variables, as appropriate. SPSS version 15.0 (Chicago, IL) was used for all data processing and analysis.

Back to Article Outline

Results 

Of the 524 eligible health care providers, 379 (72%) participated. Sixty-eight attending physicians (70%), 87 residents (88%), 209 nurses (67%), and 15 nurse practitioners (94%) returned completed questionnaires. The majority of physicians (68%) were male, and the majority of nurses (77%) were female. Level of experience for attending physicians was demonstrated by board certification and years of experience. The majority of attending physicians, 57 (84%), were board certified or board eligible in emergency medicine, 9 (13%) were board certified in both emergency medicine and internal medicine, and 2 (3%) had other board certifications. The mean number of years of experience (post-residency) for attending physicians was 10.2 years (SD, 7.5), and the mean post-graduate year for resident physicians was 2.3 years (SD, 1.0). Nurses and nurse practitioners had a mean number of 8.8 (SD, 7.9) and 12.0 (SD, 6.2) years of experience, respectively.

When asked to define the JNC7 stage I blood pressure guidelines for hypertension, 214 respondents (56%) left this item blank and only 104 (27%) correctly listed both the systolic and diastolic criteria for stage I hypertension.¹⁰ A greater proportion of nurse practitioners (53%) than nurses (21%) responded correctly (P = .008). Of physicians, residents (41%) were more likely than attending physicians (25%) to respond correctly (P = .03). For attending physicians, there was no difference in the proportion of correct responses between those who were board certified in emergency medicine only (25%) and those board certified in both emergency medicine and internal medicine (22%), P = .99. Of incorrect responses, the majority were above the JCN7 thresholds. We anticipated that the majority of respondents might not be able to complete this item and therefore asked providers to note the minimum systolic and diastolic blood pressures that would lead them to conduct a reassessment. Mean reassessment thresholds are noted in Table 2.

Table 2. Threshold for blood pressure re-assessment

SD, Standard deviation.

Table 3 presents potential causes of elevated blood pressure readings. Nurses rated undiagnosed hypertension and substance abuse higher than did physicians. No significant differences existed between ratings of nurses and nurse practitioners, nor were there differences between ratings of residents and attending physicians. “Other” causes listed included the following responses: unable to get proper equipment (11), not focused on blood pressure (2), not a high priority (2), forgot (2), patient refusal or complaint (2), and patient discharged before recheck (2). The following additional reasons were each cited one time: did not notice abnormal reading, a repeat reading not common in practice, inaccurate first reading, physicians don't want to treat high blood pressure in the emergency department, and nurses unaware of importance.

Table 3. Perceptions of potential causes of elevated blood pressure in ED patients

SD, Standard deviation.

Scale: 1 = not a common cause; 10 = very common cause.

Table 4 reports barriers to repeating a blood pressure reading in the emergency department. There were no significant differences in responses between attending and resident physicians. Nurses and nurse practitioners did not differ on responses either, with the exception of one item. Nurse practitioners rated the lack of staffing the highest of all items at 6.5, whereas nurses rated the lack of staffing at 4.7 (Table 4). “Other” causes listed included patient non-compliance (8) and the following reasons, each of which were cited once: medications/fluids, improper cuff use, patient position, environment, over-the-counter medications, sub-arachnoid hemorrhage, head injury, increased intra-cranial pressure, movement while taking blood pressure, stress, syncope, increased cholesterol, disease processes, undiagnosed renal disease, and age.

Table 4. Barriers to performing a repeat blood pressure measurement in the emergency department

SD, Standard deviation.

Scale: 1 = not an important barrier; 10 = very important barrier.

Table 5 reports the perception of adverse risk associated with elevated blood pressure at 1 year. Within 3 ranges of blood pressure, risk assessments were as follows; for pre-hypertension levels, nurses' mean adverse risk assessment was at least twice that of physicians. With increasing ranges, corresponding to stage I and stage II hypertension, nurses maintained this difference. For blood pressure ranges corresponding to stage II hypertension, nurses' perception of an adverse event at 1 year was the highest at over 75% (Table 5). The clinical meaning of this finding is unclear.

Table 5. Perception of adverse event risk (stroke, myocardial infarction, death) at 1 year for patients in the following blood pressure categories

Blood pressure ranges	Nurses (n = 224) (SD)	Physicians (n = 155) (SD)	P value
Systolic blood pressure
120-139 mm Hg	12.0 (17.3)	5.5 (6.1)	<.001
140-159 mm Hg	43.6 (28.4)	15.5 (14.6)	<.001
≥160 mm Hg	75.3 (25.6)	32.3 (26.8)	<.001
Diastolic blood pressure
80-89 mm Hg	17.5 (21.5)	6.4 (8.1)	<.001
90-99 mm Hg	49.9 (28.7)	17.4 (16.1)	<.001
≥100 mm Hg	78.7 (24.4)	34.4 (27.2)	<.001

SD, Standard deviation.

Scale: 0% = no risk; 100% = very high risk.

Nurses rated the mean liability of not advising the patient of their elevated blood pressure higher (7.6; SD, 2.5), than did attending physicians (6.5; SD, 2.4) and residents (6.0; SD, 2.2), with nurse practitioners reporting the highest perceived risk (8.7; SD, 1.7).

Back to Article Outline

Discussion 

We investigated emergency clinicians' knowledge of the JNC7 criteria, specifically stage I hypertension, causes of elevated blood pressure readings in the emergency department, self-reported barriers to repeating blood pressure readings, and perceived medical liability of not recommending a referral for definitive diagnosis and treatment. Small differences in knowledge and perception of causes of elevated blood pressure readings and potential barriers to re-assessment between provider types were found to be statistically significant, but they are most likely not clinically meaningfully different.

Only one third of ED physicians and nurses were able to accurately report the criteria for stage I hypertension and, as a group, noted higher blood pressure thresholds for re-assessment than is currently recommended. These findings may be explained because emergency nurses and physicians are not primary care providers and their focus is on the emergent complaint, or they may not be as aware of JNC7 guidelines. While emergency physicians and nurses may be unfamiliar with the JNC7 guidelines, and it may be unclear how this guideline should be applied in the ED setting, the American College of Emergency Physicians has published a clinical policy that is meaningful to emergency clinicians: “Critical Issues in the Evaluation and Management of Adult Patients with Asymptomatic Hypertension in the Emergency Department.”⁵ This guideline recommends referral for follow-up for evaluation of possible hypertension and blood pressure management for ED patients with persistently elevated blood pressure readings. Optimal screening and referral interventions depend on health care providers being able to identify patients at high risk of undiagnosed hypertension, and this should include knowledge of the current blood pressure values that meet the definition of hypertension. This knowledge deficit may be a contributing factor to the limited referrals for treatment for patients with elevated blood pressure readings in the emergency department; however, other reasons may exist.

Health care providers ranked uncontrolled, known hypertension, pain, and anxiety as the top reasons for elevated blood pressure readings in the emergency department. It is important to further characterize patients with known but uncontrolled hypertension. Some patients may have been lost to follow-up or non-compliant with medications. The majority may already have a primary care physician and require changes to their anti-hypertensive medication regime. Pain or anxiety as causes for elevated blood pressure during the triage process generally are considered temporal conditions that will resolve once medical management is under way. However, evidence in this area does not support this belief.¹¹, ¹², ¹³ Tanabe and colleagues¹¹ followed up on 156 patients with 2 elevated ED blood pressure readings who repeated blood pressure readings at home 1 week following an ED visit. The difference between home and ED systolic blood pressure measurements was not associated with anxiety (r = –.03; P = .69) and showed a slight association with pain in the opposite direction from what was expected (r = .18; P = .03).¹¹

Finally, nurses and physicians both highly ranked the possibility of undiagnosed hypertension as a cause of elevated blood pressure in the ED patient population. While emergency physicians and nurses should be cautious in diagnosing an ED patient with hypertension, the recent evidence and adoption of the ACEP policy on undetected hypertension suggest it is prudent to advise patients of this possibility and need for definitive follow-up.⁵

An important first step in identifying patients for referral for definitive hypertension evaluation and identifying patients with known but uncontrolled hypertension is for health care providers to follow the JNC7 guidelines and ACEP policy and obtain repeat readings when blood pressure is elevated.⁵, ¹⁰ As previously noted, re-assessment practices by ED health care providers remain poor, in spite of recent recommendations.^9,14, ¹⁵, ¹⁶ We hypothesized that barriers to blood pressure re-assessments may play a role; however, in our investigation, health care providers did not identify any barrier greater than 5 when using a 10-point Likert-type scale. Lack of time and staffing were the only barriers that emerged as a moderately important. Health care providers did not rank “ED blood pressure is not a priority,” “ED blood pressure readings are inaccurate,” or “additional readings would not alter my treatment” as significant barriers, as we expected. In clinical practice and anecdotally, these reasons often are cited as to why blood pressure re-assessments are not performed. In addition to heightened awareness to abnormal vital signs, adoption of policies or automatic electronic alerts may improve the re-assessment rates for patients with elevated blood pressure readings.

Finally, despite the low referral rates previously reported for the subjects in the study, the providers perceived a relatively high risk of medical liability associated with not informing patients of their elevated blood pressure.⁹ This is an interesting finding, but the meaning is unclear.

Limitations 

This investigation was a self-report survey, and no attempt was made to describe actual practice patterns of individual physicians or nurses. A socially desirable response bias may have resulted in under-reporting of barriers to blood pressure re-assessment. Four of the five centers included in the project were affiliated with academic medical centers and may not reflect general physician and nurse opinions.

Back to Article Outline

Implications for Emergency Nurses 

Emergency nurses routinely obtain vital signs and are in the position to recognize patients with elevated blood pressure readings and to repeat a blood pressure reading prior to discharge. If the blood pressure is still elevated, emergency nurses have a unique opportunity to provide a brief motivational interview recommending follow-up with a primary care physician for definitive diagnosis. If blood pressure re-assessment and patient education were to become routine practice, many patients with undiagnosed or uncontrolled hypertension could be identified earlier in the disease process, thus preventing strokes, heart attacks, and renal failure. Despite overcrowding, emergency nurses could make a significant impact on the co-morbidities associated with uncontrolled hypertension. It is often the nurse who provides discharge teaching, and the role of the nurse remains critically important in the health care system.

Back to Article Outline

Conclusion 

Only 27% of ED health care providers were aware of the JNC7 stage I hypertension criteria and often attributed elevated blood pressure readings to chronic, uncontrolled hypertension, pain, or anxiety. No single strong barrier to repeating blood pressure readings was clearly identified by the providers.

Back to Article Outline

Acknowledgments 

We thank all of the physicians and nurses who completed the survey.

Back to Article Outline

References 

1. Thorpe KE, Howard DH. The rise in spending among Medicare beneficiaries: the role of chronic disease prevalence and changes in treatment intensity. Health Aff. 2006;25:w378–w388
   • View In Article
2. Lloyd-Jones D, Adams R, Carnethon M, et al. Heart disease and stroke statistics—2009 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation. 2009;119:e21–e181
   • View In Article
   • CrossRef
3. Kahn R, Robertson RM, Smith R, Eddy D. The impact of prevention on reducing the burden of cardiovascular disease. Circulation. 2008;118:576–585
   • View In Article
   • CrossRef
4. Irvin CB. Public health preventive services, surveillance, and screening: the emergency Department's potential. Acad Emerg Med. 2000;7:1421–1423
   • View In Article
   • MEDLINE
   • CrossRef
5. Decker WW, Godwin SA, Hess EP, Lenamond CC, Jagoda AS, American College of Emergency Physicians Clinical Policies Subcommittee on Asymptomatic Hypertension in the ED . Clinical policy: critical issues in the evaluation and management of adult patients with asymptomatic hypertension in the emergency department. Ann Emerg Med. 2006;47:237–249
   • View In Article
   • Full Text
   • Full-Text PDF (137 KB)
   • CrossRef
6. Kelen GD. Public health initiatives in the emergency department: not so good for the public health?. Acad Emerg Med. 2008;15:194–197
   • View In Article
   • CrossRef
7. Bernstein SL, Haukoos JS. Public health, prevention, and emergency medicine: a critical juxtaposition. Acad Emerg Med. 2008;15:190–193
   • View In Article
   • CrossRef
8. Gaddis GM, Hauswald M. The provision of public health services in the emergency department: “begin with the end in mind”. Acad Emerg Med. 2008;15:198–200
   • View In Article
   • CrossRef
9. Baumann B, Cline D, Cienki J, Egging D, Lehrmann J, Tanabe P. Provider self-report and practice: reassessment and referral of emergency department patients with elevated blood pressure. Am J Hypertens. 2009;22:604–610
   • View In Article
   • CrossRef
10. Chobanian AV, Bakris GL, Black HR, et al. for the National Heart, Lung, Blood Institute Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, National High Blood Pressure Education Program Coordinating Committee The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 Report. JAMA. 2003;289:2560–2572
    • View In Article
    • MEDLINE
    • CrossRef
11. Tanabe P, Persell SD, Adams JG, McCormick JC, Martinovich Z, Baker DW. Increased blood pressure in the emergency department: pain, anxiety, or undiagnosed hypertension?. Ann Emerg Med. 2008;51:221–229
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (192 KB)
    • CrossRef
12. Backer HD, Decker L, Ackerson L. Reproducibility of increased blood pressure during an emergency department or urgent care visit. Ann Emerg Med. 2003;41:507–512
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (66 KB)
    • CrossRef
13. Chernow S, Iserson K, Criss E. Use of the emergency department for hypertension screening: a prospective study. Ann Emerg Med. 1987;16:180–182
    • View In Article
    • Abstract
    • Full-Text PDF (287 KB)
    • CrossRef
14. Glass RI, Mirel R, Hollander G, Krakoff LR, Karlin R, Failor RA. Screening for hypertension in the emergency department. JAMA. 1978;240:1973–1974
    • View In Article
    • MEDLINE
15. Lehrmann JF, Tanabe P, Baumann BM, Jones MK, Martinovich Z, Adams JG. Knowledge translation of the American College of Emergency Physicians clinical policy on hypertension. Acad Emerg Med. 2007;14:1090–1096
    • View In Article
    • CrossRef
16. Umscheid CA, Maguire MG, Pines JM, et al. Untreated hypertension and the emergency department: a chance to intervene?. Acad Emerg Med. 2008;15:529–536
    • View In Article
    • CrossRef