Antibiotic
Prescription In Upper Respiratory Tract Infections
Cheong
Lieng Teng,
Senior Lecturer,
International Medical University
Kwok
Chi Leong,
Part-time Lecturer,
International Medical University
Syed
Mohamed Aljunid,
Professor,
Department of Community Health,
Faculty of Medicine,
Universiti Kebangsaan Malaysia,
Malaysia.
Molly
Cheah,
President,
Primary Care Organisation Malaysia.
Abstract
Aims. To document the antibiotic prescribing rate for
upper respiratory tract infections (URTI) in general practice and
its associated factors.
Methods.
Data extracted from a morbidity survey of 150 general practice clinics
in three urban areas in Malaysia. Participating general practitioners
recorded demographic, morbidity and process of care data for 30 consecutive
adult patients using a structured form.
Results.
URTI contributed 940 (27.0%) of the total of 3481 encounters recorded.
Antibiotic was prescribed in 68.4% of encounters with URTI; a significant
proportion of the antibiotic choice was inappropriate. Half the antibiotics
prescribed in this study were due to URTI.
Conclusions.
General practitioners need to re-examine their own prescribing for URTI
and decide whether it is consistent with current guidelines. Rational
prescribing is not just part of the professional role of doctors, but
will go a long way to impede the emergence of antibiotic resistance.
Keywords:
Respiratory tract infections, antibiotics, physician practice patterns,
family practice
Introduction
Upper respiratory tract infection is a common problem seen in primary
care. Although it is generally believed that there is over-prescription
of antibiotic for URTI in general practice, there are few reports of this
in the indexed literature from the Asia-Pacific region.(1)
Chang et al.(1)
in a one-week prescription study in Taiwan, reported that antibiotic was
prescribed in 31.3% of patients with common cold. Aljunid (2)
reported a marked difference in the antibiotic prescription rates for
URTI in private and government clinics in one district (75.9% and 45.5%
respectively).
While
antibiotic is credited with the dramatic reduction in the morbidity and
mortality associated with many bacterial infections, its abuse has resulted
in the rapid emergence of resistant strains that reduce the effectiveness
of many antibiotics.(3)
It has been recognized that the problem of antibiotic abuse is a result
of a complex interplay of various socio-cultural, economic and cognitive
factors at the level of the patients, the prescribers and the drug industry.(4)
In
this study, we report the factors associated with the prescribing of antibiotic
for URTI in Malaysian general practice. The data were extracted from the
study "Cost and Quality of Care in Three Urban Areas in Malaysia".
(5,6)
Materials
and Methods
Sampling
and setting
A list of private general practice clinics (n=639) was created by perusal
of the list of registered medical practitioners from Malaysian Medical
Council (1995). Proportionate random samples of 150 clinics were selected
(Kuala Lumpur 101, Penang 25 and Ipoh 24). These clinics were approached
by mail and later visited personally by research assistants. The study
was conducted over six months in the year 1999.
Questionnaire
and definitions
In
the morbidity component of this study, participating general practitioners
were requested to complete Data Encounter Form for each of the 30 consecutive
adult patients seen (age ³18 years). The Data Encounter Form was
a 2-page questionnaire that asked for the following information from the
clinical encounter: demographic data, reasons for encounter (RFEs, up
to 5), physical findings, diagnoses (up to 2), investigation ordered,
outpatient procedures performed, medical certificate given, medication
prescribed (up to 8, but only a maximum of 5 items were analysed), and
referral made.
The
sources of payment were originally coded as cash (out-of-pocket payment
by patients), panel (patients or clinics claiming the consultation fee
from the employers) and managed care (payment is paid via a managed care
organisation, primarily by capitation). Panel system and managed care
were recoded as "non-cash" as subsequent analyses showed that
they are similar for patient's demographic characteristics, morbidity
and process of care.
Data
analysis
We used SPSS version 10 for data entry and analysis. The morbidity
data was coded using ICPC-2, (7)
this was facilitated by using ICPC-2 plus Demonstrator (courtesy of Family
Medicine Research Unit, Dept of General Practice, University of Sydney).
Categorical
and continuous variables were compared using c2-test and t-test respectively.
Statistical significance is set at p<0.05. Multinomial logistic regression
was used to look for independent association between age, Chinese ethnicity,
fever and sore throat and antibiotic prescription.
Results
One
hundred and twenty five clinics returned 3481 complete Data Encounter
Forms. Encounters with ICPC Diagnosis codes R74, R75 and R76 were classified
as URTI (Table 1). We have classified as URTI in 11 encounters where diagnoses
were recorded as symptoms only (R21 and R25) after verifying the chief
complaints recorded were consistent with URTI. Thus the number (%) of
encounter was 940 (27.0%).
Table
1: ICPC diagnosis codes of URTI encounters
ICPC
code |
Symptoms/diagnoses |
Number
(%) |
R21 |
Throat
symptoms |
10
(1.1) |
R25 |
Sputum/phlegm
abnormal |
1
(0.1) |
R74 |
Acute
upper respiratory infection |
874
(93.0) |
R75 |
Acute
sinusitis |
1
(0.1) |
R76 |
Acute
tonsillitis |
54
(5.7) |
Demographic
characteristics
As
shown in Table 2, consultations for upper respiratory tract infections
were more common in males, those in the non-cash payment system and those
who were employed. URTI was less commonly seen in the 'Other' ethnic group
who were mostly immigrant workers.
Table
2: Demographic characteristics of patients with and without upper respiratory
tract infections
Characteristics |
URTI |
Not
URTI |
Statistical
test |
Gender
Male
Female
|
490
(29.1)
450 (25.0) |
1192
(70.9)
1349 (75.0) |
c2=7.48,
p=0.006 |
Ethnic
group
Malay
Chinese
Indian
Others |
507
(27.2)
253 (28.7)
147 (26.5)
33 (18.1) |
1355
(72.8)
630 (71.3)
407 (73.5)
149 (81.9) |
c2=8.60,
p=0.035 |
Payment
system
Cash
Non-cash |
358
(24.0)
582 (29.3) |
1135
(76.0)
1406 (70.7) |
c2=12.14,
p<0.001 |
Employment
Yes
No |
767
(28.8)
141 (22.0)
|
1896
(71.2)
500 (78.0) |
c2=12.01,
p=0.001 |
Factors
influencing antibiotic prescribing
Antibiotic
was prescribed for 33.4% of all encounters and for 68.4% (95%CI 65.4%,
71.4%) diagnosed to be URTI. Antibiotic was prescribed in 67.2% of encounters
coded as R74 (acute upper respiratory infection) and 90.7% of encounters
coded as R76 (acute tonsillitis). Antibiotic was prescribed more commonly
in patients with URTI than those without URTI (68.4% versus 20.5%, c2=707.36,
p<0.001). URTI contributed 55.2% of all antibiotics prescribed in his
study.
Antibiotic
prescribing did not differ by gender (males 70.4%, females 66.2%, c2=1.902,
p=0.168), payment system (cash 70.1%, non-cash 67.4%, c2=0.78, p=0.377)
and employment status (employed 67.9%, unemployed 71.6%, c2=0.757, p=0.384).
Antibiotic
prescribing differed significantly by ethnic groups (Malays 61.5%, Chinese
77.1%, Indians 76.9%, Others 69.7%; c2=24.76, p<0.001). Patients prescribed
antibiotic were slightly older than those not given antibiotic (mean ages
34.2 versus 32.2 years, t=2.65, p=0.008).
Antibiotic
prescribing for various URT symptoms were as follow: fever 72.7%, cough
68.9%, sore throat 78.8%, runny nose 65.5%, phlegm 66.7% and hoarseness
66.7%. Fever (c2=6.596, p=0.01) and sore throat (c2=27.467, p<0.001)
were significantly associated with antibiotic prescribing.
Four
factors that were initially associated with antibiotic prescribing (age,
Chinese ethnicity, fever, sore throat) were tested with multinomial logistic
regression; the last three factors remained independently associated with
antibiotic prescribing (Table 3).
Table
3: Unadjusted and adjusted odds ratios of factors associated with antibiotic
prescribing
Characteristics
|
Antibiotic
prescription rate
|
Unadjusted
odds ratio (95%CI) |
Adjusted
odds ratio (95%CI) |
Chinese |
77.1% |
1.79
(1.29, 2.50) |
1.67
(1.19, 2.36) |
Fever |
72.7% |
1.44
(1.09, 1.91) |
1.64
(1.23, 2.19) |
Sore
throat |
78.8% |
2.25
(1.66, 3.01) |
2.22
(1.62, 3.04) |
Antibiotic
choice
Table 4 showed the antibiotic group and six most common antibiotics prescribed
in the patients with URTI.
Table
4: Antibiotic choice in URTI
Antibiotic
group |
Number
(%)** |
Antibiotic
name |
Number
(%) |
Penicillins
|
389
(59.4)
|
Amoxycillin
Ampicillin
|
279
(42.6)
68
(10.4)
|
Sulphonamides
|
68
(10.4) |
Co-trimoxazole |
58
(8.8) |
Cephalosporins |
60
(9.2) |
Cephalexin |
40
(6.1) |
Tetracyclines
|
59
(9.0) |
Doxycycline |
45
(6.9) |
Macrolides
|
58
(8.9) |
Erythromycin |
49
(7.5) |
Others* |
21
(3.2) |
|
|
Total |
655
(100) |
|
539
(82.3) |
*
aminoglycosides, quinolones, metronidazole, lincomycin
**in 13 encounters two antibiotics were prescribed.
Discussion
The research methodology in this study relies on the conscientious recording
by the participating general practitioners, for which we were unable to
verify by direct examination of the actual clinical records. Nonetheless,
we feel that the data collected broadly apply to the adult attendees in
the urban Malaysian general practice for the following reasons: (a) high
response rate (83.3% of clinics approached returned the encounter forms),
(b) the profile of the general practitioners in this study was similar
to those in the West Malaysia,(6,8)
(c) missing data for medication in URTI encounters was only 1.7% (data
not shown), and (d) similarly high antibiotic prescribing rate for URTI
had been reported in a smaller Malaysian general practice survey.(2)
URTI
contributed at least one-quarter of all encounters sampled from the general
practice clinics. The differences in the consultation rates for URTI for
various demographic subgroups suggest the complex interplay of many factors
that lead to a consultation for URTI in general practice.
Antibiotic
was prescribed for 68.4% of the encounters diagnosed to have URTI. The
prescribing rate was high irrespectively of the demographic characteristics
and clinical features, although we found that Chinese ethnicity, the history
of fever and sore throat were significantly associated with antibiotic
prescription. The poor recording of physical findings in this morbidity
survey did not allow a more detailed analysis of the clinical decision-making
of the general practitioners. However, the prescribing of antibiotic is
somewhat indiscriminate and appears to be inconsistent with the guidelines.(9,10)
The
choice of antibiotics was by and large appropriate with respect to their
ability to eradicate the group A b-haemolytic streptococcus, the most
important bacterial pathogen in URTI. However, some choices were clearly
inappropriate on account of the sensitivity towards group A b-haemolytic
streptococcus (e.g. sulphonamides, tetracyclines, metronidazole).(9,10)
The prescribing of newer antibiotics (e.g. azithromycin and quinolones)
was relatively uncommon.
This
study illustrates that antibiotic prescribing for URTI in Malaysian general
practice is a suitable target of intervention since it contributed at
least half of all antibiotics prescribed in general practice. Snow et
al, (9)
in keeping with systematic review(11)
of the predictive features of streptococcal pharyngitis, recommended starting
empirical antibiotics (either penicillin V, amoxycillin or erythromycin)
for adults with at least three of four clinical criteria (history of fever,
tonsillar exudate, tender anterior cervical lymphadenopathy, and absence
of cough). However, the problem of patient expectation, either implied
or expressed, for antibiotic in general practice is keenly felt by general
practitioners and possibly influence their prescribing behaviour.(12)
Thus clinical trials aimed at increasing adherence to evidence-based guidelines
in URTI have had mixed success so far. (13-15)
Summery
of Implications for GPs
The
high antibiotic prescribing in URTI is likely to encourage the emergence
of antibiotic resistance. Reducing antibiotic use may require a major
change in the mindset for both general practitioners and the patients.
Rational prescribing in URTI is consistent with the doctors' professional
role and may not lead to a disruption of doctor-patient relationship.
Acknowledgement
We
wish to thank the Family Medicine Research Unit, Department of General
Practice, University of Sydney for providing a copy of ICPC-2 Demonstrator.
We greatly appreciated the willingness of the participating general practitioners
for providing the clinical data. This project was funded by the Intensified
Research in Priority Areas (IRPA Grant, Code no: 06-02-02-0061).
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