Continuity of prescribing with inhaled corticosteroids and control of asthma.

Purpose-Current asthma guidelines advocate early intervention with inhaled corticosteroids. The aim of the study was to examine the association between continuity of dispensed prescribing for inhaled corticosteroids, and hospitalization for asthma or use of high dose oral corticosteroids.Methods-Using the MEMO record-linkage database we identified subjects receiving inhaled corticosteroids (aged 12 - 45 years). Compliance was estimated by calculating the number of days, for which a subject could have taken an inhaled corticosteroid. In the 90-day exposure-window, subjects with 90 days therapy were considered to be 'compliant', those with 1 - 89 days to be 'partially compliant', and those with zero days to be 'non-compliant'.Results-There were 4535 subjects who had 88 occurrences of hospitalization for asthma, and 457 subjects with either hospitalization or high dose oral corticosteroids. The proportion of hospitalizations for compliant, partially compliant and noncompliant subjects was 9, 3 and 1%. The odds-ratios, versus compliance, were 0.34 (95% CI, 0.19 - 0.62) for partial compliance, and 0.10 (95% CI, 0.05, 0.19) for non-compliance. This association disappeared after adjustment for beta-agonists and other relief medication.Conclusions-As dispensed prescribing decreased, the incidence of hospitalization and high dose oral corticosteroids decreased. Patients with good continuity of prescribing had the highest rates of serious asthma-related outcomes. Copyright (c) 2000 John Wiley & Sons, Ltd.