Objective To assess the effects of a multifaceted educational intervention in Norwegian general practice aiming to reduce antibiotic prescription rates for acute respiratory tract infections and to reduce the use of broad spectrum antibiotics.
Design Cluster randomised controlled study.
Setting Existing continuing medical education groups were recruited and randomised to intervention or control.
Participants 79 groups, comprising 382 general practitioners, completed the interventions and data extractions.
Interventions The intervention groups had two visits by peer academic detailers, the first presenting the national clinical guidelines for antibiotic use and recent research evidence on acute respiratory tract infections, the second based on feedback reports on each general practitioner’s antibiotic prescribing profile from the preceding year. Regional one day seminars were arranged as a supplement. The control arm received a different intervention targeting prescribing practice for older patients.
Main outcome measures Prescription rates and proportion of non-penicillin V antibiotics prescribed at the group level before and after the intervention, compared with corresponding data from the controls.
Results In an adjusted, multilevel model, the effect of the intervention on the 39 intervention groups (183 general practitioners) was a reduction (odds ratio 0.72, 95% confidence interval 0.61 to 0.84) in prescribing of antibiotics for acute respiratory tract infections compared with the controls (40 continuing medical education groups with 199 general practitioners). A corresponding reduction was seen in the odds (0.64, 0.49 to 0.82) for prescribing a non-penicillin V antibiotic when an antibiotic was issued. Prescriptions per 1000 listed patients increased from 80.3 to 84.6 in the intervention arm and from 80.9 to 89.0 in the control arm, but this reflects a greater incidence of infections (particularly pneumonia) that needed treating in the intervention arm.
Conclusions The intervention led to improved antibiotic prescribing for respiratory tract infections in a representative sample of Norwegian general practitioners, and the courses were feasible to the general practitioners.
The main effects of this study of a prescription peer academic detailing intervention (Rx-PAD) were a decrease in overall prescription rates for antibiotics for acute respiratory tract infections and, in particular, an increased use of the narrow spectrum agent penicillin V when an antibiotic was issued.
Whereas reductions were seen in the intervention arm, both prescription rates and proportions of non-penicillin V antibiotics increased in the control arm. The greater increase in the number of episodes of acute respiratory tract infections in the intervention arm after intervention compared with the control arm could have affected the prescription rates if the diagnostic drift mainly tended towards diagnoses with a low prescribing rate; however, we found no evidence of this. The general practitioners in the intervention arm would probably have had greater awareness of acute respiratory tract infection diagnoses as a consequence of the intervention and therefore have recorded them more often.
As measured by unadjusted means (table 2⇑), the change in total antibiotic prescribing rate was relatively small and its clinical significance may be debatable. However, the reduction in prescribing of broad spectrum antibiotics was substantial and of clinical importance because of the reduction in promoting resistance. The adjusted outcome measures show a more consistent effect of the intervention, with odds ratios of 0.72 and 0.64, and are closer to the effect estimates of the study.
The larger effects on antibiotic treatment for acute bronchitis and acute sinusitis were intentional, as parts of the intervention focused on the overuse of antibiotics for these diagnoses. Another topic particularly covered in the intervention was the overuse of macrolides. A major part of the increase in the proportion of penicillin V can be explained by a decrease in use of this antibiotic group.
The control arm received another intervention, and the mere participation in a course could possibly have affected the outcome of antibiotic prescribing, although the topic of antibiotic use was not part of the control arm course. However, we found no indication of such effects when we compared the distribution of different prescribed antibiotics typically used for acute respiratory tract infections in the control arm with the total sales in Norway for the same period.
When we were planning this study, the hypothesis was that an improvement in prescription behaviour could be obtained in a group setting where the participants knew each other well and were used to discussing challenging topics related to their own clinical practices. In the continuing medical education group setting, each participant was confronted with, and had to reflect on, the baseline report on their own prescription practice. We believe that this was a key component for obtaining improved prescription habits.
We had an expectation of greater effects of the intervention among the general practitioners with the highest baseline prescribing rates, but this was not the case. Whether the effect of such an intervention would be higher in countries with high prescribing is not easy to predict from our data.