Differential prescribing of inhaled corticosteroids in New Zealand general practice.

AIM

To determine how inhaled budesonide, beclomethasone and fluticasone are prescribed by general practitioners in New Zealand.

METHODS

Retrospective study of computerised clinical records from 42 general practices in New Zealand for the period 1 July 1997 to 30 June 1998. The study population comprised 174 929 consulting patients, of whom 9878 patients were prescribed budesonide, fluticasone, or beclomethasone with full dosing instructions.

RESULTS

The mean daily prescribed dose was higher for patients receiving inhaled budesonide (886 microg) than beclomethasone (547 microg), a difference of 339 microg (95% CI 311 microg to 367 microg), and fluticasone (508 microg), a difference of 378 microg (95% CI 344-412). The difference between mean daily prescribed doses of beclomethasone and fluticasone was 39 microg (95% CI 15-63). The overall difference was consistent across age groups and with different types of inhalation device. Evidence of systematic prescribing of higher doses of budesonide to patients with more severe asthma was not found. Patients prescribed fluticasone were more likely to have been prescribed oral steroids in the preceding year.

CONCLUSIONS

Conclusions about the relative potencies of inhaled corticosteroids cannot be made with the data presented. However, data presented show that inhaled corticosteroids have not been prescribed in line with their reported relative potencies. This study provides benchmark data for the prescribing of inhaled steroids in New Zealand general practice.