Proactive, nurse-run asthma care in general practice reduces asthma morbidity: scientific fact or medical assumption?

Nurse-run asthma care in general practice in the United Kingdom has become extremely common, particularly since the introduction of the 1990 contract for general practitioners, but there have been few controlled trials of the clinical effectiveness of this approach to asthma care. A study attempted to compare the outcome of asthma care over three years in two similar practices when one practice provided proactive, nurse-run care and the second continued with a traditional (reactive) approach, and to examine the process of care when such changes were introduced. Despite the investment of considerable resources, statistically significant differences could not be shown between the two practices using a comprehensive variety of outcome measures. This could be interpreted as meaning that nurse-run asthma care may be ineffective, but the negative outcome is much more likely to reflect difficulties in the manner in which the intervention practice sought to develop its service and in the research process. There were extensive methodological problems leading to a potential type 2 error. A randomized controlled trial of nurse-run asthma care would now be difficult to conduct, and so it may be necessary to accept nurse-run asthma care without definitive proof of its clinical effectiveness.