Transcript No Slide Title

IMPACT OF AN ESSENTIAL DRUGS LIST AND TREATMENT
GUIDELINES ON PRESCRIBING IN SOUTH AFRICA
Pillay T, Hill SR
School of Medical Practice and Population Health, The University of Newcastle, Australia
Problem Statement: In 1998, the South African health department introduced standard
treatment guidelines for various medical conditions including hypertension. The impact of
these guidelines on prescribing has not been assessed at provincial level.
Drug supply data
• The drug supply database was used to calculate the total
volume of each antihypertensive drug supplied (as PRPs)
to all provincial hospitals over a six month period,
grouped into pharmacological class.
• The proportion (%) of each drug class supplied to each
hospital over the 6 month period was calculated.
• Hospitals were ranked on the basis of their usage of
methyldopa as high, medium and low prescribers of
methyldopa.
Objectives: To identify trends in antihypertensive medication use from supply data and
patient prescription surveys.
Design and Setting: Cross-sectional survey using supply data from the provincial
medicines depot (PMSC) database to generate a 6-month summary report of
antihypertensive supply. Thereafter antihypertensive prescription audits were conducted at
selected public hospital pharmacy departments in the province of Kwazulu Natal (KZN).
Study Population: The PMSC database was used to analyse drug supply data to the 63
KZN hospitals. Prescriptions for antihypertensive therapy presented by patients to public
hospital pharmacy departments were used in the drug utilisation review.
Methods: The PMSC database was used to generate a summary report of volumes of each
antihypertensive supplied to KZN hospitals. This summary report was used to determine the
relative usage of each antihypertensive, by hospital. Fifteen hospitals were selected for an
audit of antihypertensive prescriptions. At each of the selected hospitals, 100 consecutive
antihypertensive prescriptions presented to the hospital pharmacy departments were
recorded into a database and later analysed.
Prescription Audit Data:
Monotherapy/Combination Therapy
100
90
Monotherapy
80
Combination Therapy
70
% Prescribed
Methods (continued)
Abstract
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Conclusions: The study results demonstrate that supply data is useful in identifying
prescribing trends that can be further quantified through prescription audits. This
methodology would be most useful in resource-poor settings. Furthermore, analysis of drug
supply data and the prescription audit suggest that prescribers in KZN public hospitals are
not compliant with hypertension treatment guidelines.
Background and Setting
• In 1998 the National Department of Health (NDOH)
published standard treatment guidelines (STG) for
the management of common medical conditions
(including hypertension) at all public health facilities
in South Africa. These treatment guidelines were
designed to assist prescribers in making appropriate
health care decisions in specific clinical
circumstances. The guidelines were distributed
through each of the provincial health departments to
prescribers in the province.
• It is unclear exactly what impact the guidelines have
had on prescribers considering that the passive
distribution of clinical guidelines has limited effect on
changing prescriber behaviour.
• Two previous surveys (at institutional level) of
antihypertensive prescribing reported that prescribers
are non-compliant with the STG for hypertension.
Methyldopa was reported to be prescribed to 33% of
the hypertensive patients.
Results: Drug Supply Data
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D
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J
K
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M
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P
Hospitals
Figure 3: Proportion of monotherapy / combination therapy at hospitals in Kwazulu
Natal Province.
Comparison of the two methods
Level of
Use
Drug use from
Standard
supply data
treatment (proportional
guideline
use)
Prescription
survey
(proportional
use)
Prescription
survey
(proportion
from 100
scripts)
1st Line
Diuretic
2nd Line
Reserpine ACEI (27%)
ACEI (29.5%)
ACEI (57.6%)
3rd Line
Beta
blockers
Methyldopa
(10%)
CCB (12.4%)
CCB (24.2%)
4th Line
ACEI
Reserpine
(7%)
Beta blocker
(6.7%)
Beta blocker
(13.1%)
5th Line
CCB
Beta blocker
(6%)
Methyldopa
(4.9%)
Methyldopa
(9.5%)
6th Line
Alpha
Blocker
CCB (6%)
Reserpine
(2.7%)
Reserpine
(5.3%)
Hydrallazine
(1%)
Hydrallazine
(0.2%)
Hydrallazine
(0.4%)
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Percentage of total antihypertensives supplied
(standard deviation)
Results: Analysis of the supply data suggested that diuretics were the most widely
prescribed, followed by ACEI, methyldopa, reserpine, calcium channel blockers and beta
blockers. If prescribers complied with hypertension treatment guidelines, the usage pattern
(declining order of volume) would have been diuretics, reserpine, beta blockers, ACEI,
calcium channel blockers. Prescription audits at selected hospitals suggest that clinicians
prescribe (in declining order of volume) diuretics, ACEI, calcium channel blockers, beta
blockers, methyldopa, reserpine and hydrallazine.
Prescription audit data
• 16 institutions were selected from the three categories of
methyldopa use (low, moderate and high) for the
prescription survey. The sample included hospitals from
different regions within the province, both urban and rural.
• 100 consecutive original prescriptions presented to the
outpatient department for the management of
uncomplicated essential hypertension were used to record
the names and doses of the antihypertensives prescribed.
Prescriptions for patients with co-morbidities were not
included in the survey.
• The prescriptions were analysed to determine the
proportion of each antihypertensive class, proportion of
prescriptions for monotherapy and combination therapy,
the doses of antihypertensives prescribed and whether
there were any significant differences between the results
of the supply data and prescription data.
0
Diuretics (42%) Diuretics
(43.5%)
Diuretics
(85.0%)
30
7th Line
20
10
0
Diuretics
ACEI
Methyldopa
Reserpine
Beta
blockers
CCB
Other
Drug Class
Figure 1: Proportion of antihypertensives supplied to hospitals over a six month period
Study Aims
Methyldopa Supply to Hospitals
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Methods
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Two methods of assessing drug utilisation were
used:
• a drug supply database for 63 hospitals in
KZN province
• a prescription audit of a sample of these
hospitals.
The supply data suggest that diuretics (hydrochlorothiazide)
and ACEI are the first choice agents followed by methyldopa,
reserpine, beta blockers and calcium channel blockers.
Supply data are not an accurate reflection of use, particularly
for drugs with multiple indications such as ACEI.
Nevertheless, the drug use patterns were a useful indicator
that informed the selection of hospitals for the prescription
survey. The prescription survey is a more accurate measure
of prescribing patterns.
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Number of hospitals
• To identify the relative use of various antihypertensive
drugs at the 63 provincial hospitals using supply data.
• To supplement the supply data findings through a
survey of patient prescriptions at 16 hospitals in the
province.
• To determine whether supply data is a useful indicator
of drug use.
• To determine whether there are any similarities
between the prescribing of antihypertensive drugs
and the recommendations of the treatment guidelines.
Conclusion
low (<5%)
moderate (5-12%)
high (>12%)
Categories of methyldopa supply
The survey of hypertension prescriptions suggests a similar
trend (following the recommended stepped care approach) of
first line diuretics (mainly hydrochlorothiazide), followed by
angiotensin converting enzyme inhibitors (perindopril),
calcium channel blockers, beta blockers, methyldopa,
reserpine and hydrallazine.
Figure 2: Number of hospitals in each category of methyldopa supply
Acknowledgements
T Pillay was supported by an AusAID fellowship.
WHO Collaborating Centre for Training in Pharmacoeconomics and Rational Pharmacotherapy