Audit of hypertensive patients in Dr Nigel Watson's practice led to changes in practice that significantly improved the percentage with adequate BP control


   

Hypertension is one of the most common medical conditions in adults, with an incidence of 5–30%, depending on age, sex and ethnic origin.1–3 Hypertension is a very significant cause of stroke, myocardial infarction and premature death.2

It has been proved that good control of blood pressure significantly decreases the morbidity and mortality from stroke and myocardial infarction for hypertensive patients.2 However, studies have shown that <15% of all hypertensive patients have well controlled blood pressure.4

The 1999 British Hypertension Society (BHS) guidelines give clear advice on optimum blood pressure control.1

 

  • To agree a practice-based management protocol based on the 1999 BHS guidelines
  • To measure practice care against recommendations
  • To identify where care needs to be improved
  • To produce an action list as a result of the first audit
  • To repeat the audit after 6–12 months.

 

The practice has been fully computerised for more than 10 years and has 12 400 registered patients. A computer search for all patients aged 75 years or less with a diagnosis of hypertension was undertaken. The initial search in May 1999 identified 810 such patients. The computer records of all these patients were examined.

The findings were compared after each 100 patients' records had been examined. This showed a consistent finding of ±2.5% in all areas, confirming that a sample group of 100 would reflect the findings for a larger group.

In April 2000 the computer search was repeated and identified 910 patients aged 75 years or less with a diagnosis of hypertension.

A random sample of 100 patients was identified for the second audit.

 

1. Patients diagnosed as hypertensive must be recorded in the practice hypertension register.

It is widely accepted that a disease register is the cornerstone of good systematic care. Follow-up of patients with a chronic disease is often inadequate.

The 'rule of halves'4 states that only about half of all hypertensive patients have been diagnosed. Of those diagnosed only half receive treatment, of whom only half will be adequately controlled. The net result is that only 10-15% of hypertensive patients receive good care.

A register allows a call and recall system, to ensure regular follow-up, and identifies defaulters.

2. The records show that the patient has been reviewed in the past 6 months.

There is good evidence that many patients default from follow-up. Failure to be monitored is associated with poor outcome. A study in Sheffield showed that one of the major avoidable factors contributing to deaths from strokes and myocardial infarction was failure to attend for follow-up for hypertension.

Follow-up should reflect the patient's needs, but patients should be reviewed at least every 6 months.2

3. The records show that the ypertension is well controlled, defined as <150/90mmHg in a patient without diabetes and <140/85mmHg in a patient with diabetes. Both systolic and diastolic levels must be obtained.

The benefits of reducing blood pressure to these levels in hypertensive patients are now unquestionable. Reduction in blood pressure to <150/90mmHg in patients without diabetes and <140/85mmHg in patients with diabetes reduces their risk of stroke and heart attack by 20-50%.

The BHS guidelines, in fact, go beyond this, and state that optimal therapy should aim to achieve blood pressures of <140/85mmHg in patients without diabetes and <140/80mmHg in patients with diabetes. However, it is recognised that these levels are not realistic at the present time.

4. The records show that data on smoking have been recorded in the past 5 years.

Smoking is a significant risk factor for coronary heart disease (CHD) and stroke. When combined with hypertension, the risks to the patient are significantly increased. All hypertensive patients who smoke should be encouraged to stop.

5. The records show that data on alcohol have been recorded in the past 5 years.

There is good evidence that a high alcohol intake raises blood pressure and increases the risk of premature morbidity and mortality.2 A reduction in alcohol intake reduces blood pressure and improves outcome.

It is estimated that 10% of hypertensive patients have alcohol-induced hypertension.

The aim of reducing excessive alcohol intake is to lower blood pressure and so reduce the risk of stroke. The BHS recommends the avoidance of >21 units a week in men and >14 units a week in women.

Moderate alcohol intake has a protective effect against CHD – light drinking (1-2 units) per day is not contraindicated.

6. The records show that body mass index (BMI) has been recorded in the past year.

Weight reduction has been shown to reduce blood pressure as well as cardiac risk.3

 

All patients aged 75 years or less.

 

Standards for the audit are shown in Table 1.

Table 1: Standards for the hypertension audit

Standard
Target
All patients with hypertension are on the practice's hypertension register
100%
All patients have had a blood pressure check within the past 12 months
100%
All patients have had a blood pressure check within the past 6 months
90%
All patients have their blood pressure well controlled as defined in criterion 3
50%
All records have data recording smoking history in past 5 years
70%
All records have data recording alcohol history in past 5 years
70%
All patients have body mass index recorded in the past year
50%

 

The first audit identified 810 patients aged 75 years of age or less with hypertension. The majority (88%) had had their blood pressure recorded in the previous 12 months. Of the 12% who had not attended for a blood pressure check, 75% were either receiving no treatment or being prescribed one class of antihypertensive drug. The BHS guidelines state that most patients with hypertension will require combination therapy to control blood pressure adequately.

Control of blood pressure was found to be poor. This was largely because of the number with blood pressures of 150–160/90mmHg, which were considered normal before the publication of the 1999 BHS guidelines.

Closer attention needs to be paid to both smoking and alcohol history, as only 64% and 62% respectively had had this recorded in the previous 5 years.

Only 27% of patients had had a BMI recorded in the previous 12 months.

 

1. Management plan agreed with partners and practice/district nurses

2. Hypertension register

All patients who have been diagnosed hypertensive will have the appropriate Read code entered on the computer. They will therefore form part of a disease register.

  • Follow-up

The GP or practice nurse will inform patients of the appropriate interval for follow-up each time the patient attends an appointment.

  • Prescription review

When a patient has his/her blood pressure checked, the medication would be authorised for the appropriate number of issues. When a prescription is requested and the authorisation has expired, action can be taken to review the patient.

  • Call and recall

The audit revealed that a number of patients failed to attend for a blood pressure check. This was least likely to occur in patients on three or more classes of drugs or in patients with diabetes.

(i) All patients identified during the audit with no blood pressure recording in the past 12 months were noted and their names given to their GP for action.
(ii) A computer report, identifying all patients who were hypertensive and had not had their blood pressure checked in the past 12 months, was written. The report then marks the computer notes with a reminder. The reminder will signal to anyone looking at the notes that a blood pressure check is required. This report will be run every 3 months.
  • Recording of data

To achieve consistency in data recording, all GPs are encouraged to use the SOPHIE computer program for hypertension. This asks structured questions, and the answers are automatically 'Read coded' and entered on the patient's notes.

  • Patient information leaflet

A patient information leaflet on hypertension was produced.

 

The second audit was carried out in April 2000. A total of 910 patients aged less than 75 years with a diagnosis of hypertension were identified.

A random sample of 100 patients whose details were recorded on the computer were then examined using the same criteria as in the first audit.

 

Table 2 and Figures 1 and 2, below, show a comparison of the results.

Table 2: Comparison of the results of the first and second hypertension audits

Year
Disease register
BP (past 12 months)
BP (past 6 months)
Adequate BP control
Smoking data (past 5 years)
Alcohol data (past 5 years)
Weight recorded in past year
1999
100%
88%
78%
27%
64%
62%
27%
2000
100%
95%
84%
70%
78%
72%
38%
 
Figure 1: Recording of lifestyle data and weight measurement
bar chart
Figure 2: Blood pressure (BP) control
bar chart

 

The first audit has produced the following benefits to patient care:

  • 95% of hypertensive patients have had their blood pressure recorded in the past 12 months (+7%)
  • 84% of hypertensive patients have had their blood pressure recorded in the past 6 months (+6%)
  • There has been a significant improvement in the percentage of patients with adequate blood pressure control (+43%)
  • There has been a slight improvement in the number of patients with a record made of smoking data (+14%) and alcohol data (+10%).

The following problems remain:

  • Only 38% of hypertensive patients have had their BMI measured in the past 12 months.
  • Only one or two doctors and the practice nurses are using SOPHIE, so recording of data is incomplete.
  • There is a marked difference between clinicians with regard to updating of information relating to smoking, alcohol, and measurement of BMI.
  • Assessment of cardiovascular risk and advice regarding aspirin and statins still appears to be variable.

An audit summary is shown in the box below.

Audit summary

Aims: To ensure that all patients aged 75 years or less with hypertension are monitored regularly, have their risk factors assessed and achieve optimum blood pressure control
Criteria
1999
2000
Target 2001
% increase from 2000 audit
needed to reach 2001 target
Disease register
100%
100%
100%
Blood pressure (past 12 months)
88%
95%
100%
+5%
Blood pressure (past 6 months)
78%
84%
90%
+6%
Blood pressure control adequate
27%
70%
75%
+5%
Smoking data (past 5 years)
64%
78%
90%
+12%
Alcohol data (past 5 years)
62%
72%
90%
+18%
Body mass index (past 12 months)
27%
38%
70%
+32%

 

  1. Whelton PK. Epidemiology of hypertension. Lancet 1994; 344:101-6.
  2. Ramsay LE, Williams B, Johnston GD et al. British Hypertension Society Guidelines for hypertension management 1999: summary. Br Med J 1999; 319: 630-5.
  3. O'Brien E. ABC of Hypertension. 3rd edn. London: BMJ Books, 1995.
  4. Smith WC, Lee AJ, Crombie IK et al. Control of blood pressure in Scotland: the rule of halves. Br Med J 1990; 300: 981-3.

Guidelines in Practice, August/September 2000, Volume 3
© 2000 MGP Ltd
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