Transcript WHO PRESCRIBING INDICATORS (1991 – 1995)

WHO PRESCRIBING INDICATORS
(1991 – 1995)
TRENDS AND PERSPECTIVES
IN AN OUTPATIENT HEALTH CARE
FACILITY IN BENIN CITY, NIGERIA.
1Isah
AO, 2Isah EC, 3Aghomo OE,
Departments of 1Medicine, 2Community
Health and 3Clinical Pharmacy,
University of Benin,
Benin City, Nigeria
WHO Prescribing indicators (1991 – 1995): Trends and perspectives
in an Outpatient Health Care Facility in Benin City, Nigeria
1Isah AO, 2Isah
EC, 3Aghomo OE
Departments of 1Medicine, 2Community Health, and 3Clinical Pharmacy, University of Benin,
Benin City, Nigeria; INRUD/Nigeria
ABSTRACT
Problem Statement: Irrational prescribing is a feature of health care practice in developing countries. This has
been highlighted by the use of the WHO prescribing indicators, which has shown a high number of drugs per
prescription and the injudicious use of antibiotics and injections. A number of other factors also influence the
prescription of drugs.
Objectives: To evaluate the prescription pattern using the WHO indicators in the immediate five-year period
(1991–1995) following the official adoption of the National Essential Drug Program and the introduction of a
National Drug Policy document in 1989 and 1990, respectively.
Design: Retrospective time-series design.
Setting and Population: Prescription records (100 per month) issued to patients and filled at the pharmacy of the
outpatient department of the University of Benin Teaching Hospital during the period 1991–1995 were
retrieved.
Outcome Measures: WHO prescribing indicators: average number of drugs/encounter; percentage of drugs
prescribed by generic name; percentage of encounters prescribed antibiotic; percentage of encounters
prescribed injection; percentage of drugs prescribed from the Essential Drugs List. 1991 was used as the
baseline year.
Results: The clinic was run by about 10 doctors daily during the period. The average number of drugs per
encounter was 3.0 (range 2.9–3.1). The percentage of encounters prescribed injections was 29.9% in 1991,
with a decrease in 1994 (to 16.0%) that was sustained in 1995 (when it was 13.9%). This may be due to the
initial fright from overt cases of HIV/AIDS seen during this period. The percentage of encounters prescribed
antibiotics steadily increased from 36.1% (1991) to 46.6% (1995). There were no significant changes in the
percentage of generic drugs prescribed or in the percentage of EDL drugs prescribed. There were some
seasonal effects on the prescribing indices, with a greater number of drugs, antimalarials, and antibiotics
being prescribed in the late wet season.
Conclusions: The study found minimal changes in the prescribing indicator values during the immediate period
following the introduction of the National Drug Policy and suggested some seasonal fluctuation in drug use.
INTRODUCTION
• The period from the mid 1970’s to the 90’s were characterized
by an intensive effort to improve the drug supply systems and
to promote rational use of drugs in developing countries.
• In Nigeria, the Essential Drugs concept was embraced in 1989
following a presidential decree and a National Drug Policy
document was adopted in 1990.
• The WHO prescribing indicators provide a methodology to
profile in an objective and reproducible manner the effects of
this policy development as well as other factors on drug use
OBJECTIVES
This study evaluated the prescription pattern using
the WHO indicators over a 5-year period(19911995) following the official adoption of Essential
drugs program and introduction of the national
drug policy document in 1989 and 1990
respectively
METHODS
• Study Location: University of Benin Teaching Hospital,
Benin- City, Nigeria.
• Study setting : General Practice Clinic/Pharmacy. The clinic was
run by about 10 doctors during the period.
• Study design: Retrospective time series
Prescription orders presented at the Pharmacy were filled and
retained during the period.A total of 100 prescription per month
was selected by systematic random sampling for the period January
1991 to December 1995
• Outcome measures: The WHO prescribing indicators were derived
from the information obtained from the prescriptions. Additionally,
encounters in which analgesics, antimalarial drugs as well as
combination of antibiotics+antimalarial drugs were prescribed were
noted
METHODS
Data analysis
• The WHO prescribing indicator values were derived for
each month and year from 1991 – 1995
• Average number of drugs per prescription
• The proportion of prescriptions expressed as percentage
with other identified variable – injections, antibiotics, drugs
prescribed by generic name and those listed in the National
EDL. {Values for analgesics, antimalarials and
coprescription of antimalarials + antibiotics were noted)
• The results are expressed as the mean values and analysis of
variance (ANOVA) was used to detect differences between
multiple mean values
• Level of significance p< 0.05
RESULTS
• There were no significant changes in the average number of
drugs prescribed per encounter during the period 1991 – 1995
[Table 1]
• A level change was observed for injection encounters (29.9%
in 1991 to 16.0% in 1994), however this did not achieve
statistical significance when compared with other years (F =
0.511; p= 0.884) [Figure 1]
• No significant changes were observed for other indicators
however, there was a trend to increasing use of antibiotics
[Table 1, Figure 1]
• Further analysis of commonly prescribed drugs revealed non
significant decline in the use of analgesics and
antimalarials.[Table 1, Figure 2]
• Figures 3 & 4 shows an increasing use of injections,
antimalarials and co-prescription of antimalarials and
antibiotics during the wet season.
Table 1
The core prescribing indicators in the UBTH
General Practice Clinic (1991–1995)
INDICES
1991
1992
Average no. of drugs
3.1
3.1
per encounter
% of encounters with 29.9 32.8
injection
% of encounters with
36.1 36.3
antibiotics
% of drugs prescribed
39.6 42.3
by generic names
% drugs listed in EDL
96.8
97.2
1993
1994
1995
3.0
2.9
34.9
16.0
13.9
37.9
45.6
46.6
3.1
44.1
41.8
44.7
96.4
97.2
96.3
Fig 1. The core prescribing indicators in the UBTH
General Practice Clinic - trends for 1991–1995
Indicator value (%)
50
40
30
20
10
0
1991 1992 1993 1994 1995
YEAR
% Injections
% Antibiotics
% Generics
Percentage of encounters
Fig 2. The percentage encounter with drugs in
some therapeutic categories (1991 – 1995)
90
80
70
60
50
40
30
20
10
0
1991
% Analgesics
1992
1993
Year
% Antimalarials
1994
1995
% Antimalarials + antibiotics
The core prescribing indicators in the General
Practice Clinic-monthly trends for 1991–
50
40
30
20
10
l
Au
g
Se
p
O
ct
No
v
De
c
0
Ju
Indicator values (%)
1995
Ja
n
Fe
b
M
ar
Ap
r
M
ay
Ju
n
Fig 3.
Months of the year
% Injections
% Antibiotics
% Generics
Figure 4.
100
80
60
40
20
Se
p
O
ct
N
ov
D
ec
Ju
l
Au
g
0
Ja
n
Fe
b
M
ar
Ap
r
M
ay
Ju
n
Drug classes prescribed
(%)
The encounters (%) with commonly prescribed drug
classes- monthly trends (1991 –1995)
Months of the Year
% Analgesics
% Antimalarials
% Antimalarials + antibiotics
CONCLUSION
 The findings show minimal changes of the WHO
prescribing indicators in the period following the
introduction of the essential drug concept and
development of a national drug policy.
 The observed decrease in the use of injections may
be due to the HIV/AIDS scare following the initial
cases seen reinforcing rational drug use activities
 There was also increasing use though marginal of
some drugs and injections in the wet season.