The use of asthma medications among asthma cases in Saskatchewan from January 1, 1991 to December 31, 2000

Asthma affects nearly two and a half million people in Canada. In Saskatchewan, the prevalence of asthma has increased across all age groups since 1981. Current literature indicates that the purchase of all asthma medications increased in the last 20 years both province and nationwide. Since the early 1990s, the Canadian Consensus Guidelines (CCG) for the treatment of asthma recommended increasing the use of inhaled corticosteroids as a mainstay for controlling asthma symptoms. The CCG have also encouraged decreasing the use of short-acting, inhaled beta2-agonist medication. The objective of this descriptive epidemiological study was to investigate asthma medication prescribing at the individual level among physician-diagnosed asthma patients, aged 0 to 64 years, in Saskatchewan from January 1, 1991 to December 31, 2000. Saskatchewan residents covered under the provincial health insurance plan who received a physician’s diagnosis of asthma, identified each calendar year, were included in the study (296,430 asthma patients in total). Nearly 80.0% of this asthma population purchased at least one asthma medication in each calendar year. From 1991 to 2000, users and the mean number of prescriptions of short-acting beta2-agonists decreased slightly. The proportion of users and mean number prescriptions per year of inhaled corticosteroids increased. The highest mean numbers of prescriptions and users of inhaled corticosteroids were among the 0-4 year olds. Short-acting beta2-agonists, inhaled corticosteroids, and oral corticosteroids were the most popular medications. Users of theophyllines and cromoglycates decreased. The 15-34 year old males showed the greatest "inappropriate" use as high users of short-acting beta2-agonists and low users of inhaled corticosteroids. There was increasing compliance with the CCG over the ten years. The combination of beta2-agonists with inhaled corticosteroids usurped beta2-agonist monotherapy as the most popular form of asthma therapy by the year 2000. Users of combination therapy increased from 19% to 38.7%, while users of beta2-agonists alone decreased from 34.5% to 23.1%. From 1996 to 2000, the monthly number of both short-acting beta2-agonists and inhaled corticosteroids prescriptions decreased for all users in July and August. Peak increases in the number of short-acting beta2-agonist prescriptions, for children under 15, occurred in September. For adults, peak increases occurred in December for both medications. These study results will enhance the understanding of asthma medication use among children and adults and will help healthcare professionals develop new treatment programs for the management of asthma