Antibiotic prescribing in acute infections of the nose ... - Oxford Journals

Family Practice © Oxford University Press 2001

Vol. 18, No. 2 Printed in Great Britain

Antibiotic prescribing in acute infections of the nose or sinuses: a matter of personal habit? An I De Sutter, Marc J De Meyere, Jan M De Maeseneer and Wim P Peersmana De Sutter AI, De Meyere MJ, De Maeseneer JM and Peersman WP. Antibiotic prescribing in acute infections of the nose or sinuses: a matter of personal habit? Family Practice 2001; 18: 209–213. Background. A proper understanding of how and why GPs prescribe antibiotics in general practice is essential for the design of strategies aimed at making prescribing more rational. Objective. The intention of this study is to contribute to such understanding by investigating which elements are important in the GP’s decision to prescribe antibiotics for patients with acute infectious complaints of the nose and/or sinuses. Methods. During their training in general practice, students observed the following elements while attending encounters between their trainer-GP and patients with a runny nose, blocked nose or cough: patient characteristics, contact characteristics, signs and symptoms, diagnosis and prescriptions. Information on practice characteristics and characteristics of the trainer-GP were collected. Data were analysed using multiple logistic regression and multiple linear regression. Results. A total of 722 cases were analysed with the following results: the best independent predictor of an antibiotic prescription is the individual antibiotic prescribing rate (IAPR), which expresses the personal habit of the GP in prescribing antibiotics [adjusted odds ratio (OR) 5.27, 95% confidence interval (CI) 3.22–8.62]. Others are the diagnostic labels ‘sinusitis’ (adjusted OR 2.80, 95% CI 1.2–6.49) and ‘flu-like syndrome’ (adjusted OR 0.08, 95% CI 0.01–0.45), and the sign ‘sinus tenderness’ (adjusted OR 4.37, CI 2.15–8.89). The antibiotic prescribing behaviour intensifies with an increasing tendency to prescribe medication in general (β = 0.46, P , 0.00) and with an increasing defensive attitude (β = 0.22, P , 0.05). Conclusions. Whether or not a patient with an acute infection of the nose and/or sinuses will be handed an antibiotic prescription seems to depend more on the attending doctor’s prescribing behaviour than on the clinical picture. Further qualitative research into attitudes which may be related to a high tendency to prescribe antibiotics consequently is of the utmost importance. Keywords. Antibiotic prescribing, family practice, physician’s practice patterns, prescribing behaviour, upper respiratory tract infections.

the disease to run its natural course is probably the best approach:1 clinical trials show that benefit from antibiotics is minimal, while other opposing arguments include adverse side effects, development of bacterial resistance and the financial cost to the patient and society. Strategies to change prescribing behaviour will only be successful when they are based on a proper understanding of how and why GPs prescribe antibiotics. In this study, our aim was to contribute to this understanding by exploring to what extent various factors— such as the diagnostic label, the patient’s signs or symptoms and contextual factors—are important in the GP’s

Introduction In general practice, acute upper respiratory tract infections are one of the main reasons for prescribing antibiotics. However, evidence is mounting that in nonimmune-compromised patients, watchful waiting for

Received 22 February 2000; Revised 12 July 2000; Accepted 30 October 2000. Department of General Practice and Primary Health Care, and aDepartment of Population Studies and Social Science Research Methods, University of Gent, De Pintelaan, 185, B-9000 Gent, Belgium.

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decision to prescribe antibiotics for patients with acute infectious complaints of the nose or sinuses.

Methods In 1996, during three periods of 1–4 days, students of the medical school of Gent (Belgium) undergoing elective vocational training in general practice observed the encounters of their trainer-GP with patients having one of the following symptoms: runny nose, blocked nose and/or cough. They registered patient characteristics, signs and symptoms, diagnostic label and treatment (Tables 1 and 2). Data on the observed GPs were also collected (Table 1). The ‘defensive attitude score’ expresses the GP’s ‘risk-avoiding attitude’ and was measured using a validated questionnaire: the higher the score, the more the GP will always prefer the certain to the uncertain.2 The individual antibiotic prescribing rate (IAPR) measures the tendency to prescribe antibiotics and was calculated by dividing the number of encounters with an antibiotic prescription by the total number of encounters registered with this GP. The tendency to prescribe in general is the mean number of medications prescribed per registered contact. Analysis Data were entered in SPSS 7.5 for Windows. Statistics used were odds ratios (ORs), Pearson’s correlation coefficients, Student’s t-test, multiple linear regression and multiple logistic regression.

Results Eighty GPs participated. Four were women, 72 had more than 10 years’ experience in practice and 47 worked in a single-handed practice. A total of 722 out of 1052 registered encounters were analysed; all patients with a normal clinical pulmonary examination and at least one symptom related to the nose or sinuses were included. The patient’s mean age was 32 years, and 55% were women (Table1). The best independent predictor of an antibiotic prescription was the IAPR of the prescribing GP. Others were the diagnostic labels ‘sinusitis’ and ‘flu-like syndrome’, and the sign ‘sinus tenderness’ (Table 2). The IAPR of the GPs varied extensively from 0 to 100%: some prescribed no antibiotics at all; others prescribed them in every encounter (Table 1). The mix of diagnoses allocated by doctors with a high IAPR was not significantly different from that of those with a low IAPR (data not in table). The IAPR intensifies with an increasing tendency to prescribe medication in general and with an increasing defensive attitude (Table 1).

Discussion Our main finding is that patients with complaints of the nose or sinuses are prescribed antibiotics primarily because they consult a GP who usually prescribes antibiotics for this disease, and not so much because they are suffering from certain signs or symptoms or because a particular diagnosis has been made. The results show that GPs have very divergent antibiotic prescribing behaviours and that precisely this personal tendency is the best predictor—better than diagnosis or signs and symptoms —of whether or not a patient will be prescribed an antibiotic. Several studies3,6–9 have already drawn attention to the importance of contextual factors in prescribing but, to our knowledge, this is the first time that it has been shown, in quantitative terms, that non-biomedical factors can be even more important than clinical facts in antibiotic prescribing. Also significant, but to a lesser extent, are the ‘flu-like syndrome’ label associated with fewer antibiotic prescriptions and the ‘sinusitis’ label associated with more, which confirms previous research.3 However, frequencies of various diagnostic labels are not significantly different between low and high prescribers, which rather contradicts Howie’s statement that diagnoses are chosen as a justification for treatment.4 Finally, ‘tenderness of the sinuses’, an important sign for GPs when making the diagnosis ‘sinusitis’,5 is apparently an indication of sinus involvement and thus a reason to prescribe more antibiotics in other diagnoses too. With regard to the method, using students as observers made it possible to collect data on real patient encounters, thus avoiding possible bias by self-reporting or reporting on simulated case histories. Nonetheless, all participating GPs inevitably were trainers associated with the university and, moreover, well aware of being observed. However, this probably made their antibiotic prescribing more uniform and ‘by the book’ and actually makes the variations in IAPR even more remarkable. The students, moreover, recorded only facts. The influence of other factors known to be important, such as patients’ expectations,6 the doctor–patient relationship7,8 and psychosocial background features9 were not investigated. It is unlikely, however, that these factors would increase the importance of clinical facts in prescribing antibiotics. In our data, we found two indications why some GPs prescribe more antibiotics than others. First, high prescribers are GPs who prescribe a lot of medication in general. They prescribe antibiotics in addition to symptomatic therapy and not as a substitute for it. Secondly, high prescribers have a ‘defensive attitude’, which means that they are unwilling to take risks and have problems in coping with uncertainty. Both of these findings are in line with previous research.2,3,10 Interestingly, research also shows that defensiveness is not merely a personal characteristic of GPs but can be

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Antibiotics for nose and sinus infections TABLE 1

Relationships between antibiotic prescribing and patient, encounter and doctor characteristics

Patient and encounter characteristics and correlations with number of antibiotic prescriptions Patients

No. (%) with antibiotic

Gender

OR (95% CI) prescription

Female Male

140/385 (36) 110/321 (34)

1.1 (0.79–1.51)

Chronic respiratory disease

Yes No

13/28 (46) 245/694 (35)

1.59 (0.51–4.88)

Age

,10 10–65 .65

53/131 (40) 173/491 (35) 11/41 (27)

Home visit

Yes No

67/179 (37) 173/495 (35)

1.11 (0.77–1.61)

Follow-up encounter

Yes No

53/149 (35) 193/539 (36)

0.99 (0.67–1.47)

Chi square P = 0.254

Encounter

OR

Doctors’ characteristics and correlation with IAPRa Pearson’s R

Mean (SD) IAPRb

0.39 (0.32)

Defensive scoreb Tendency to prescribe in

P-value

16 (3.9) generalb

Tendency to make home visitsb

0.299

0.016

1.66 (0.62)

0.451

0.000

0.26 (0.23)

0.084

0.49

–0.028

0.83

Mean difference in IAPR

P-value

n (%) No. of years in practice n = 74

,5 5–10 11–20 21–30 .30

0 8 (11) 37 (50) 24 (32) 5 (7)

Comparison of IAPR between different groups of GPs: Student t-test n (%) University of graduation

Ghent Other

60 (75) 20 (25)

0.009

0.93

Practice type

Solo Group

47 (62) 29 (38)

0.038

0.63

Gender

Male Female

76 (95) 4 (5)

0.18

0.20

Multiple linear regression analysis of IAPR on tendency to prescribe and score of defensive attitude B Tendency to prescribe Score defensive attitude

28.37 1.62

95% CI 14.91–41.82 0.001–3.246

β

P-value

R2

0.458

,0.00

0.292

0.217

,1.05

a Number of encounters with antibiotic prescription registered/total number of encounters registered with GP; b calculated only for GPs with a minimum of five encounters registered (n = 69).

212 TABLE 2

Family Practice—an international journal Variables associated with prescribing an antibiotic to a patient with acute infectious complaints of the nose and/or sinuses: biavariate and multivariate analysisa No. with ab prescription (%)

Category of IAPRc 1., 0, mean of all GPs

Cat = 1 193/329 (59)

Diagnostic label

Cat = 0 65/393 (17)

Crude ORs (95% CI)b

Adjusted ORs (95% CI)

7.16 (5–10.27)

5.27 (3.22–8.61)

With this label

With other label

Sinusitis

29/55 (53)

212/632 (34)

2.21 (1.23–3.99)

2.8 (1.2–6.49)

Pharyngitis

24/49 (49)

217/638 (34)

1.86 (1–3.47)

1.97 (0.85–4.57)

Rhinosinusitis

36/93 (39)

205/594 (35)

1.20 (0.75–1.92)

1.15 (0.58–2.29)

Rhinopharyngitis

44/118 (37)

197/569 (35)

1.12 (0.73–1.73)

0.96 (0.46–1.97)

Flu-like syndrome

22/114 (19)

219/573 (38)

0.39 (0.23–0.65)

0.08 (0.01–0.45)

Rhinitis

24/134 (18)

217/553 (39)

0.34 (0.20–0.55)

0.60 (0.27–1.32)

Present

Absent

58/97 (60)

200/625 (32)

3.16 (1.99–5.02)

4.37 (2.15–8.89)

Symptoms and signs Sinus tenderness Purulent secretion on tonsils

d

9/15 (60)

249/707 (35)

2.76 (0.89–8.82)

3.38 (0.9–12.73)

Post-nasal drip

20/44 (45)

238/678 (35)

1.54 (0.80–2.96)

2.15 (0.97–4.79)

Purulent rhinorroea

41/78 (60)

104/334 (31)

2.45 (1.44–4.17)

1.96 (0.96–3.99)

Swelling of submandibular glands

55/122 (54)

203/600 (34)

1.61 (1.06–2.43)

1.48 (0.88–2.47)

Productive cough

122/269 (45)

136/453 (30)

1.93 (1.40–2.68)

1.37 (0.85–2.23)

Sore throat

111/280 (40)

147/442 (33)

1.32 (0.95–1.82)

1.35 (0.87–2.08)

Red inflammation of throat

127/326 (39)

131/396 (36)

1.29 (0.94–1.77)

1.29 (0.83–2)

Elevated temperature

85/224 (38)

173/498 (35)

1.15 (0.82–1.61)

1.15 (0.75–1.74)

General symptoms

200/563 (36)

58/159 (36)

0.96 (0.65–1.41)

1.03 (0.63–1.69)

Runny nose or stuffy nose

188/549 (32)

70/173 (40)

0.77 (0.53–1.11)

1 (0.62–1.58)

Sinus pain in history

48/113 (42)

210/609 (34)

1.40 (0.91–2.15)

0.93 (0.5–1.73)

127/353 (36)

131/396 (36)

1.02 (0.74–1.40)

0.88 (0.58–1.35)

Swelling nasal mucosa (rhinoscopia)

75/231 (32)

183/491 (37)

0.81 (0.57–1.14)

0.88 (0.56–1.39)

Non-productive cough

84/287 (29)

173/435 (40)

0.62 (0.45–0.86)

0.85 (0.56–1.31)

Purulent secretions in nose

14/28 (50)

244/694 (35)

1/84 (0.81–4.17)

0/77 (0.28–2.15)

Headache

a Multiple logistic regression analysis; method: enter; b adjusted for all variables listed in the table; c IAPR = number of encounters with antibiotic prescription/total number of encounters of GP (analysed encounter not included); d reference is mean prescription rate for all diagnoses.

determined in part by the structure of the health care system the GP works in, which illustrates the complexity of prescribing behaviour.2 In conclusion, our results show that to design effective strategies aimed at rationalizing antibiotic prescribing, further research into individual prescribing habits and their determinants could well be more important than collecting rational arguments based on clinical evidence.

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