Bronchodilator treatment and asthma death: A new analysis of a British case-control study

We investigated the relationship between asthma mortality and long-acting beta(2)-agonists (LABA), including interactions with age, inhaled corticosteroids (ICS) and social deprivation.

We used a new, expanded dataset of recorded medication extracted blind from the anonymised primary care records of an earlier British case-control study. The cases were 532 asthma deaths aged < 65 occurring between 1994 and 1998 and the controls were 532 asthma admissions, matched for age, hospital, and index date (date of death/asthma admission). The exposure periods prior to the index date were current (<= 2 months) or recent (> 2-6 months).

We found no evidence of an overall association with current (OR = 0.89 [95% confidence interval 0.61-1.30]) or recent (1.08 [0.76-1.53]) mention of LABA, but there was some evidence of a positive interaction with age. Among controls with mention of LABA, a concurrent mention of ICS (within 1 month) was common (85% and 93% for the two respective periods) which limited our power to investigate any interaction between LABA and ICS. There was no coherent evidence of effect modification by social deprivation.

In a population based case-control study where prescription of LABA without concomitant ICS was uncommon there was no evidence of an overall association between LABA and asthma death. (c) 2010 Elsevier Ltd. All rights reserved.