Which patients are prescribed inhaled anti-asthma drugs?

Prescribing rates for inhaled anti-asthmatic drugs in the UK vary considerably from area to area and between individual practices. The objectives of this study were to determine the prevalence of patients prescribed inhaled steroids and beta agonist bronchodilators, the indications for these prescriptions, and to relate prescribing to the recorded levels of morbidity for specific respiratory disease.

Anonymised patient-specific prescription and diagnostic data were extracted from computerised general practice records for the 41 practices in the Northern region (total population 330,749) whose data had been validated for inclusion in a research databank. Patients were included if they were either prescribed an inhaled steroid or bronchodilator during a 12 month period, or had a recorded diagnosis of asthma, bronchitis or chronic obstructive pulmonary disease. Prescribing of inhalers per 1000 population was determined within age, sex, and diagnostic groups. Respiratory diagnosis rates within different patient groups were used to measure the underlying level of morbidity in the population.

Inhaled anti-asthma drugs were prescribed for 5% of the study population. Prescribing prevalences peaked at ages 5-14 (steroids 40 per 1000 population; bronchodilators 68 per 1000) and at ages 65-74 (steroids 53 per 1000; bronchodilators 79 per 1000). Prescribing frequency for both drugs increased from two or three items per patient annually at age 0-14 to about six in the over 65 age group. Of the 39,424 respiratory patients 38% received inhalers and 7% only non-inhaler medication. Inhaler therapy was used in only 6% of patients with bronchitis, but in 66% of those with asthma, though the proportions varied with patient age and gender. Study practices differed in their overall levels of both inhaler prescribing and respiratory diagnosis, and had lower prescribing patterns of these drugs than other practices in the Northern region.

Inhaled steroid and bronchodilator prescribing have age-related and gender-related prevalences. Treatment for respiratory diagnoses varies with patient age and gender, and with the diagnosis. Prescribing differences between practices are attributable to variation in both diagnostic rates for respiratory disease and therapeutic intervention patterns. For asthma patients study practices show consensus in approach, perhaps illustrating the value of clear guidelines for asthma prescribing.