agonists
BACKGROUND: Recent studies have raised concern that regular inhalation of beta2       -agonists may cause a worsening of asthma control compared with on-demand dosing        regimens.
BACKGROUND: Recent studies have raised concern that regular inhalation of beta2       - @SUBJECT$  may cause a worsening of asthma control  @PREDICAT$  with on-demand dosing         @OBJECT$ .