Antibiotic selection patterns in acutely febrile new outpatients with or without immediate testing for C reactive protein and leucocyte count

Abstract

Background: Excessive use of broad spectrum antibiotics is related to the spread of drug resistant bacterial strains in the community.

Aim/methods: The effects of immediate testing for C reactive protein (CRP) and white blood cell count (WBC) on physicians' choices of antibiotic was investigated in patients with acute infection. Acutely febrile new outpatients were randomised into two groups: group 1 (147 patients) underwent CRP and WBC testing before initial consultation (advance testing). Prescriptions were compared with those in group 2 (no advance testing; 154 patients).

Results: In non-pneumonic acute respiratory tract infections, 61 (58%) and 122 (91%) of group 1 and 2 patients were prescribed antibiotics, respectively. Cefcapene pivoxil (third generation cephalosporin) and amoxicillin were the most frequently chosen drugs for group 1 and 2, respectively. Total prescriptions of newer, extended spectrum antibiotics (cefcapene pivoxil and clarithromycin (advanced macrolide)) were reduced by 25% in group 1, although they increased in rate (41 (67%) v 55 (45%) prescriptions) because of the decreased prescription of amoxicillin. In group 1, cefcapene pivoxil was preferentially selected when WBC values were greater than 9 x 10(9)/litre. Prescription shifted to macrolides (mainly clarithromycin) in patients without leucocytosis. Patient treatment outcome did not significantly differ between the two groups.

Conclusions: The availability of CRP and WBC data during initial consultation greatly reduced prescription of amoxicillin, but had a lesser effect on newer, potent, broad spectrum antibiotics.

Figure 1

Antibiotics prescribed to patients with acute infections of the upper (pharyngitis, tonsillitis, laryngitis, and common cold) and lower (acute bronchitis) respiratory tract. Lightly shaded columns indicate patients in the advance testing group and the darker columns those in the non-advance testing group. In total, 61 of 106 advance testing patients and 122 of 134 non-advance testing patients were prescribed antibiotic(s) for non-pneumonic acute respiratory tract infections.

Figure 2

Treatment outcome in study patients. Outcome was assessed by the reconsultation rate, number of febrile days after starting treatment, changes to initial treatment at follow up consultation, decision to admit patient to hospital on reconsultation, and ordering of further laboratory tests to follow up patient condition. Lightly shaded columns indicate the number of patients in the advance testing group and darker columns the number in the group without advance testing. Duration of febrile days was evaluated in patients who filled in and returned our follow up questionnaire (59 and 45 patients with and without advance testing, respectively). The incidence of prolonged fever (⩾ 3 febrile days) was thus 45% and 42% in the respective patient groups.