Objectives: To explore the influence of a guideline-based computerised decision support system (CDSS) on general practitioners' (GPs') management of patient cases of chronic heart failure in a pragmatic clinical situation. We assessed changes in the GPs' confidence in the diagnosis, their considerations about investigations and medications and the support they perceived from using the CDSS.
Study design: Five GPs assessed the medical records of 48 of their own authentic patient cases using a guideline-based CDSS accessible on the internet for the diagnosis and treatment of chronic heart failure, and completed a questionnaire for each case.
Outcome measures: Number of cases where the GP reported a change in confidence in the diagnosis, where the GP considered further investigations or changes in medication and the perceived support marked on a visual analogue scale.
Results: The GPs' confidence in the diagnosis changed in 25% of the cases, with equal numbers of increases and decreases in confidence. The GPs considered further investigations in 31% of the cases and medication changes in 19%. Fourteen of the 31 considered investigations and four of the ten considered changes in medications which were in agreement with the CDSS's suggestions. The GPs tended to consider further investigations more often in cases when the CDSS found the diagnosis uncertain. There was a wide range in the values for perceived support, but it could be described as substantial in 35% of the cases.
Conclusion: Using a guideline-based CDSS for the GPs' own patient cases had an impact on the GPs' confidence in the diagnosis of chronic heart failure and their considerations about investigations and medications: they also perceived substantial support in every third case. Applying a CDSS developed using evidence-based guidelines for chronic heart failure in primary care could have a significant influence on GPs' disease management.