DIFFERENCES IN UTILIZATION OF ASTHMA DRUGS BETWEEN 2 NEIGHBORING SWEDISH PROVINCES - RELATION TO PREVALENCE OF OBSTRUCTIVE AIRWAY DISEASE

Background - Considerable variation exists in the use of antiasthmatic drugs in different counties in Sweden. The reasons for this variation are unknown. A study was performed to determine if there is an association between sales of antiasthmatic drugs and the prevalence of obstructive airway diseases in two adjoining Swedish counties. Method - The prevalence of asthma-associated symptoms in the county of Jamtland where there is high drug use, and the county of Gavleborg where it is lower, was assessed in 1990 by a postal questionnaire answered by 11 300 subjects. Three age groups were included: all 16 year olds, 13% of those aged 30-39 years, and 13% of 60-69 year olds. A total of 2100 subjects reporting airway symptoms in a questionnaire and 450 asymptomatic controls were further investigated at an interview with lung function tests and, in 500 cases, with a methacholine challenge. Asthma was diagnosed in subjects reporting a typical history or repeated episodes of dyspnoea and wheezing, or dry cough combined with reversibility in FEV(15) variability in peak expiratory flow, or a PC20 value of less than or equal to 4mg/ml.