Primary objective : To investigate whether computer decision support software used in the management of patients with asthma improves clinical outcomes. Research design : Randomized controlled trial with practices each reporting on 30 patients with asthma over a 6 month period.

Methods and procedures : 447 patients were randomly selected from practice asthma registers managed by 17 general practices from throughout the UK. Intervention practices used the software during consultations with these patients throughout the study while control practices did not.

Main outcomes and results : Practice consultations, acute exacerbations of asthma, hospital contacts, symptoms on assessment and medication use. A smaller proportion of patients within the intervention group initiated practice consultations for their asthma: 34 (22%) vs 111 (34%), odds ratio (OR)= 0.59, 95% confidence interval (CI) (0.37-0.95); and suffered acute asthma exacerbations: 12 (8%) vs 57 (17%) , OR = 0.43, 95% CI = 0.21- 0.85 six months after the introduction of the computer decision support software. There were no discernable differences in reported symptoms, maintenance prescribing or use of hospital services between the two groups.

Conclusion : The use of computer decision support software that implements guidelines during patient consultations may improve clinical outcomes for patients with asthma.