An Audit of Hypertension Management in a General Out-patient Clinic

Dr. Chan Pang FaiMBBS, FHKCFP, FRACGP, DipMed (CUHK)Medical Officer, Department of Family Medicine and Primary Health Care, Tseung Kwan O Hospital, KEC cluster

Introduction and Background

Worldwide prevalence estimates that there may be as much as 1 billion individuals having hypertension.

Approximately 7.1 million deaths per year attributable to hypertension.

About 1 in 10 men and 1 in 9 women had blood pressure of 140-159/90-94mmHg of which the control rate was no more than 50% in Hong Kong.

Antihypertensive therapy associated with 35% to 40% mean reductions in stroke incidence; 20% to 25% in myocardial infarction; and more than 50% in heart failure.

A study in the community in the USA showed that of all the hypertensive subjects, only 29% were controlled to the target pressure (140/90mmHg).

Among the subjects who were receiving anthihypertensive therapy (60.7% of all hypertensive), only 47.8% were controlled to goal.

In Hong Kong, a significant proportion of patients with hypertension are managed in the Hospital Authority general out-patient clinics (GOPCs).

As a result a good care of hypertensive patients in these clinics is especially important.

In GOPCs, a lot of patients were noticed to have suboptimal control of their blood pressure and the situation was even worse in diabetic patients.

With the availability of the most updated international guidelines for hypertension management for some while already, it should be a good time to audit our practice based on those guidelines.

The Audit Questions1. What is the current standard of care of our hypertensive

patients?2. Is the blood pressure control in my clinic comparable,

better or worse than other study results?3. What are the deficiencies in the care of hypertensive

patients in my clinic?4. How can we improve our standard of care?

The Audit Cycle1) Choose a topic and planning (October to December 2004)2) Set criteria and standards

The following criteria were adopted from the audit protocol published by the Eli Lilly national Clinical Audit Centre with some modifications according to the most updated evidence-based clinical guidelines, JNC VII.

The “Must do” criteria:Criterion 1: Patients with hypertension have been recorded in a practice hypertension register.

Criterion 2: the records show that in patients without target organ damage, the blood pressure has been measured at least two separate occasions prior to commencement of drug therapy.

Criterion 3: the records show that within three consultations after diagnosis, the following symptoms and signs of target organ damage have been sought: retinopathy, left ventricular hypertrophy, angina, stroke, heart failure, peripheral vascular disease and renal disease.

Criterion 4: The records show that an assessment has been made of the risk factors for cardiovascular and cerebrovascular disease: smoking habit, BMI, diabetes mellitus, serum cholesterol, excessive alcohol intake, physical inactivity and family history of premature coronary artery disease.

Criterion 5: The records show that the mean pre-treatment blood pressure level was at least greater than 140mmHg (systolic) and/or 90mmHg (diastolic).

Criterion 6: The records show that the patient has been reviewed at regular intervals not exceeding in 6 months.

Criterion 7: The records show that the hypertensive is well controlled, the average of the last three recorded blood pressure readings <140/90 for non-diabetes and <130/80 for patients with diabetes or renal diseases.

Criterion 8: The records show that a patient with refractory hypertension and/or suspected secondary hypertension has been referred for specialist advice.

The “Should do” criteriaCriterion 9: The records show that at least annually there is an assessment of side effects of drugs.

Criterion 10: The records show that at least annually the patient has been given advice about dietary salt restriction and DASH (Dietary Approaches to Stop Hypertension) diet advice.

The standard:For criterion 1, the standard is set at 100%For criteria 2-6 and 8, the standard is set at 90%For criterion 7, the standard is set at 70%For criteria 9-10, the standard is set at 80%

3) First phase data collection and analysis (January 2005)In January 2005, a list of 5590 patients with hypertension coded by ICPC code was generated from the clinical management system (CMS).A random sample size of 360 was obtained so that the results would have a significant level of 95% confidence interval. Data was then collected by reviewing the medical records of all selected patients by using a data collection form. 349 of the sample of patients were included for data analysis with 11 rejected because they were followed up in other clinics.

Results analysis:The average age of patients was 66.1 years old. There were 142 female and 207 male patients. The result of the first cycle is summarized in Table 1:

Table 1: Number and percentage of patients with criteria fulfilled in first phase

Criteria Standard Yes No Unknown Not indicated

1. Register 100% 349 (100%) 0 (0%) / /

2. BP measured at least in 2 occasions prior to commencement of drug therapy% of cases if unknown cases excluded

90% 110 (31.5%)

87.3%

16 (4.6%)

12.7%

223 (63.9%) /

3. Symptoms and signs of target organ damage assessed:a: retinopathyb. left ventricular hypertrophyc. anginad. strokee. heart failuref. peripheral vascular diseaseg. renal disease

90%

26 (7.4%)69 (19.8%)182 (52.1%)45 (12.9%)198 (56.7%)26 (7.4%)201 (57.6%)

177 (92.6%)280 (80.2%)167 (47.9%)304 (87.1%)151 (43.3%)323 (92.6%)148 (42.4%)

///////

///////

4. Risk factors for cardiovascular and cerebrovascular disease assesseda. smoking habitb. body mass indexc. diabetes mellitusd. serum cholesterole. excessive alcohol intake f. physical inactivityg. family history of coronary artery disease

90%

348 (99.7%)344 (98.6%)329 (94.3%)316 (90.5%)347 (99.4%)285 (81.7%)343 (98.3%)

1 (0.3%)5 (1.4%)33 (5.7%)33 (9.5%)2 (0.6%)64 (18.3%)6 (1.7%)

///////

///////

5. Pre-treatment BP > 140/90% of cases if unknown cases excluded

90% 125 (35.8%)99.2%

1 (0.3%)0.8%

223 (63.9%) /

6. Patient reviewed at least every 6 months 90% 344 (98.2%) 5 (1.4%) / /

7. a. Blood pressure <140/90b. Blood pressure <130/80 for patients with diabetes or renal disease

70% 185 (53%)17 (20%)

164 (47%)67 (80%)

//

//

8. Patient referred for specialist advice% if cases not indicated excluded

90% 4 (1.1%)57.1%

3 (0.9%)42.9%

/ 342 (98%)

9. Side effects of drugs assessed annually 80% 275 (78.8%) 74 (11.2%) / /

10. Diet advice given annually 80% 237 (67.9%) 112 (22.1%) / /

4) First phase evaluation (February 2005)Deficiencies in care/service in the first cycle:

The rate of assessment of symptoms and signs of target organ damage (criterion 3) was far from the target standard. Only 7.4% of patients had been assessed for retinopathy and peripheral vascular disease and only half of the patients had been assessed for angina, heart failure and renal disease.For criterion 7, just about half of the patients had their blood pressure controlled to target and it was even worse in patients with diabetes or renal disease in which only 20% had their target achieved.For criterion 8, the result was also far from the target with only 57.1% of patients was referred for specialist assessment appropriately.The results for other criteria were quite satisfactory for the assessment of risk factors in which 6 out of the 7 risk factors were already better than the target.

5) Implementing change and interventionA copy of the latest HA hypertension management guideline was given to all doctors for reference.They were also advised to look through the JNC VII report.Templates for management of both new and old cases of hypertension and diabetes were made.A list of the audit criteria was posted up next to the computer system in every consultation room.All nurses were reminded to do the initial assessment of all new hypertensive cases in our clinic.

6) Second phase data collection and analysis (September to October 2005)

In September 2005, a list of 5804 patients were hypertension coded by ICPC code was generated from the CMS. A random sample size of 360 with 95% confidence interval was then generated.Data was then collected by the same method as in the first cycle.352 of the sample of patients were included for analysis with 8 rejected because they were followed up in other clinics.The average age of patients was 65.6 years old. There were 145 female and 207 male patients. There were 31 new cases in the sample and 13 of the new cases were diagnosed to have hypertension in our clinic.The results of the second cycle are summarized in Table 2 and 3:

Table 2: Number and percentage of patients with criteria fulfilled in second phase

Criteria Standard Yes No Unknown Not indicated

1. Register 100% 352 (100%) 0 (0%) / /

2. BP measured at least in 2 occasions prior to commencement of drug therapy% of cases if unknown cases excluded

90% 96 (27.3%)

85%

16 (4.6%)

12.7%

223 (63.9%) /

3. Symptoms and signs of target organ damage assessed:a: retinopathyb. left ventricular hypertrophyc. anginad. strokee. heart failuref. peripheral vascular diseaseg. renal disease

90%

38 (10.8%)89 (25.3%)217 (61.6%)59 (16.8%)234 (66.5%)42 (11.9%)229 (65.1%)

314 (89.2%)263 (74.7%)135 (38.4%)293 (83.2%)118 (33.5%)308 (88.1%)123 (34.9%)

///////

///////

4. Risk factors for cardiovascular and cerebrovascular disease assesseda. smoking habitb. body mass indexc. diabetes mellitusd. serum cholesterole. excessive alcohol intake f. physical inactivityg. family history of coronary artery disease

90%

352 (100%)351 (99.7%)342 (97.2%)332 (94.3%)352 (100%)340 (96.6%)351 (99.7%)

0 (0%)1 (0.3%)10 (2.8%)20 (5.7%)0 (0%)12 (3.4%)1 (0.3%)

///////

///////

5. Pre-treatment BP > 140/90% of cases if unknown cases excluded

90% 119 (33.8%)99.2%

1 (0.3%)0.8%

232 (65.9%) /

6. Patient reviewed at least every 6 months 90% 344 (97.7%) 8 (2.3%) / /

7. a. Blood pressure <140/90b. Blood pressure <130/80 for patients with diabetes or renal disease

70% 233 (66.2%)26 (32.5%)

119 (33.8%)54 (67.5%)

//

//

8. Patient referred for specialist advice% if cases not indicated excluded

90% 6 (1.7%)85.7%

1 (0.3%)14.3%

/ 345 (98%)

9. Side effects of drugs assessed annually 80% 271 (77%) 81 (23%) / /

10. Diet advice given annually 80% 319 (90.6%) 33 (9.4%) / /

Table 3: Number and percentage of new cases with criterion 3 fulfilled in second phase

Criteria Standard Yes No

3. Target organ damage assessed:a: retinopathyb. left ventricular hypertrophyc. anginad. strokee. heart failuref. peripheral vascular diseaseg. renal disease

90%12 (38.7%)16 (51.6%)30 (96.8%)15 (48.4%)30 (96.8%)14 (45.2%)27 (87.1%)

19 (61.3%)15 (48.4%)1 (3.2%)16 (51.6%)1 (3.2%)17 (54.8%)4 (12.9%)

Results and statistical analysisFor most of the criteria, there was improvement in the results in second cycle. The standard of the criteria in second phase was achieved for criteria 1, 4, 5, 6, 10. For the assessment of symptoms and signs of target organ damage, the standard for angina, heart failure was achieved but not for others.Chi-square test is used to compare the significance of the changes made in second cycle. The result was calculated by using the SPSS computer program. The result was showed in Table 4:

Table 4: Comparison of the process results in the first and second phases

Criteria Standard Phase 1 (%) Phase 2 (%) P-value

1. Register 100% 100% 100% /

2. BP measured >2 occasions prior to commencement of drug therapy

90% 87.3% 85% ↓ 0.6

3. Target organ damage assessed:a: retinopathyb. left ventricular hypertrophyc. anginad. strokee. heart failuref. peripheral vascular diseaseg. renal disease

90%7.4%19.8%52.1%12.9%56.7%7.4%57.6%

38.7% ↑51.6% ↑96.8% ↑48.4% ↑96.8% ↑45.2% ↑87.1% ↑

<0.0005<0.0005<0.0005<0.0005<0.0005<0.00050.001

4. Risk factors assesseda. smoking habitb. body mass indexc. diabetes mellitusd. serum cholesterole. excessive alcohol intake f. physical inactivityg. family history of coronary artery disease

90%99.7%98.6%94.3%90.5%99.4%81.7%98.3%

100% ↑99.7% ↑97.2% ↑94.3%↑100% ↑96.6% ↑99.7% ↑

0.9910.2150.0590.0590.475<0.00050.126

5. Pre-treatment blood pressure > 140/90 90% 99.2% 99.2% 1

6. Patient reviewed at least every 6 months 90% 98.2% 97.7% ↓ 0.41

7. a. BP <140/90b. BP <130/80 (DM or renal disease)

70% 53%20%

66.2% ↑32.5% ↑

<0.00050.074

8. Patient referred for specialist advice 90% 57.1% 85.7% ↑ 0.559

9. Side effects of drugs assessed annually 80% 78.8% 77% ↓ 0.564

10. Diet advice given annually 80% 67.9% 90.6% ↑ <0.0005

There was statistical significant improvement for all points in criterion 3 (target organ damage assessment) if only the new cases in second cycle were compared. The improvement for the assessment of physical inactivity and provision of diet advice (criterion 10) were also significant. The proportion of patients with target blood pressure reached (criterion 7) was also statistically improved for those without diabetes and renal disease.Although for those also with diabetes and renal disease, the improvement was not statistically significant, the improvement was obvious. Unfortunately, the standard for target controlled pressure for all patients could not be reached.

There was also some improvement shown for criterion 8but it was statistically insignificant. There was mild decrease in the proportion of patients who fulfilled the criteria 2 (BP taken prior drug treatment), 6 (regular review) and 9 (side effects assessment) but all of then were statistically insignificant.

DiscussionIn general, improvement was shown in most of the criteria.The improvement was impressive for the assessment of symptoms and signs of target organ damage.However, the result for the assessment of retinopathy, left ventricular hypertrophy, stroke and peripheral vascular disease was still far from the standard.

For criterion 2 (BP taken 2 occasions before initiation of drug treatment) and 5 (Pre-treatment BP >140/90), there were no obvious change in second phase and this could be explained by the small number (13) of newly diagnosed hypertension cases in the sample. For criterion 7, the proportion of patients with blood pressure controlled to target blood pressure in the first cycle was quite low (53%) especially for patients with diabetes or renal disease (20%) but the result was comparable with other studies. The results were much better in second cycle although the target standard of 70% could not be reached. One of the possible reasons was that the implementation period was only half year and most patients had only one to two follow ups during the period. As a result, even the latest blood pressure fulfilled the criteria, the average of the blood pressure of the last three consultations might not reach the target.

For criterion 4 about the assessment of risk factors, the result in the first cycle was already quite satisfactory but there was still some improvement in second phase and the target standard could be reached for all risk factors in second phase. One of the reasons for the good result was that some of the risk factors were assessed by our nurses during the initial assessment.For criterion 5 (pre-treatment BP>140/90), the target was easily achieved since nearly all old guidelines suggested start anti-hypertensive treatment at a higher blood pressure level.For criterion 6 (regular review), most of our patients were followed up in our clinic every 4-12 weeks and for those default cases, they seldom default follow up for more than 6 months.

The number of cases with suspected secondary hypertension (criterion 8) was relatively low and patient with refractory hypertension could usually be managed in general out-patient clinic. As a result, the validity of the result might be low and the standard could not be achieved.

For criterion 9, the proportion of patients with side effects assessed was not improved and this might be partially explained by the difficulty in making a template for the assessment of drugs side effects and the limit of consultation time. Nevertheless, assessment of side effects such as electrolyte disturbance caused by diuretics and ACEIs was quite often missed.For criterion 10, the proportion of patients with diet advice given was significantly improved as the criterion was relatively easy to follow.

LimitationsSome cases were excluded because they were followed up in other clinics.Some of the cases could not be assessed for criteria 2 and criteria 5 because they were diagnosed to have hypertension in other clinics. The decrease in the number of patients included for comparison would increase the bias in the results. The audit was done by reviewing the consultation notes and we could not sure whether the doctors had actually done as recorded down on the consultation notes especially when they were using the templates for recording consultation notes or copying some of the notes from previous consultation.

On the other hand, some doctors might have managed their patients according to the criteria but they did not use the template and had not recorded down all clinical information because of the time limit.The duration of the intervention phase might not be long enough for some of the criteria to achieve the standard although improvement could be shown.

ConclusionThere were some deficiencies in the management of hypertension in our clinic.However, with an audit exercise, significant improvement could be achieved. With the improvement in the care standard, we could expect that the complication rate of our hypertensive patients could be reduced. Since the standard of some of the criteria had not yet been reached, especially the assessment of some of the target organ damage and the control to target blood pressure, to repeat an audit with these criteria should be considered.

ReferenceLakhani M, Baker R, Khunti K. Management of Hypertension in Primary Care. Eli Lilly National Clinical Audit Centre. 1995.World Report 2002: Reducing Risks, Promoting Healthy Life. Geneva, Switzerland:.World Health Organization. 2002. Http://www/who/int/whr/2002/.Wong TY, Klein R, Duncan BB. Racial Differences in the Prevalence of Hypertensive Retinopathy. Hypertension. 2003;41:1086-1091.Qureshi AI, Suri MFK, Mohammad Y. Isolated and Borderline Systolic Hypertension Relative to Long-Term Risk and Type of Stroke. Stroke. 2002;33:2781-2788.Hebert LA, Kusek JW, Greene T. Effects of Blood Pressure Control on Progressive Renal Disease in Blacks and Whites. Hypertension. 1997;30:428.Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (2003). The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (The JNC 7 Report). NIH Publication No. 03-5233. Bethesda, MD: U.S. Department of Health and Human Services.Janus et al, 1997. Hong Kong Cardiovascular risk factor prevalence study 1995-1996.Beal B, MacMahon S, Chapman N. Effects of ACEinhibitors, Calcium antagonists, and Other Blood-pressure-lowering Drugs. Lancet. 2000;356:1955-1964.Lloyd-Jones DM, Evans JC, Larson MG. Differential Control of Systolic and Diastolic Blood Pressure: Factors Associated With Lack of Blood Pressure Control in the Community. Hypertension. 2000;36:594-599.Wolf-Maier K, Cooper RS, Kramer H. Hypertension Treatment and Control in Five European Countries, Canada, and the United States. Hypertension. 2004;43:10.Cheung BM, Law FC, Lau CP. The rule of halves applies in Chinese hypertensive patients. Am J Hypertens 2002; 15:209A.Doll R et al. Mortality in Reaction to Smoking: 40 years’ Observational Study on Male British Doctor. BMJ. 1994; 309:324-326.Sacks FM, Svetkey LP, Vollmer WM. Effects on Blood of Reduced Dietary Sodium and The Dietary Approaches to Stop Hypertension (DASH) Diet. N Eng J Med. 2001; 344:3-10.Whelton SP, Chin A, Xin X. Effect of Aerobic Exercise on Blood Pressure: A Meta-Analysis of Randomized, Controlled Trials. Ann Intern Med. 2002;136:493-503.Fuchs FD, Chambless LE, Whelton PK. Alcohol Consumption and the Incidence of Hypertension: The Atherosclerosis Risk in Communities Study. Hypertension. 2001;37:1242-1250.Cheng SW, Ting AC, Lau H, Wong J. Epidemiology of Atherosclerotic Peripheral Arterial Occlusive Disease in Hong Kong. World J Surg. 1999; Feb;23(2):202-6Hypertension-Management of Hypertension in Adults in Primary Care: Quick Reference Guide. National. National Institute for Clinical Excellence. August 2004.Hansson L, Zanchetti A, Carruthers SG. Effects of Intensive Blood-pressure Lowering and Low-dose Aspirin in Patients with Hypertension: Principal Results of the Hypertension Optimal Treatment (HOT) Randomized Trial. The Lancer. 1998; 351:1755-1762.Turner R, Holman R, Stratton I. Tight Blood Pressure Control and Risk of Macrovascular and Microvascular Complications in Type 2 Diabetes: UKPDS 38. BMJ. 1998; 317:703-713.American Diabetes Association. Treatment of Hypertension in Adults with Diabetes. Diabetes Care. 2003; 26(suppl 1):S80-S82.

Thank you!