Computer support is complex intervention

EDITOR—Eccles et al's rigorous approach to the evaluation of a computerised decision support system for the management of angina and asthma accounted for many of the flaws in previous trials of computer support.1 They were no doubt disappointed that no effect was seen, probably due to low usage of the system.

Although not discussed in the paper, a possible explanation for this is that, given the comparatively high use of computers required for inclusion in the trial, the practices already used simpler computerised templates to promote collection of process of care data. Practitioners may therefore have perceived little further to be gained by using the more detailed decision support system, particularly if it did not allow easy switching between the guideline and the clinical system.

The study by Eccles et al shows the complexity of interventions in primary care that incorporate computerised decision support systems. This complexity needs to be fully accounted for in designing and evaluating such interventions.2 Even with an apparently well developed piece of software, the trial assumed that offering brief training to a minority of practitioners in each practice would be sufficient for it to be incorporated into the increasingly complex care provided in routine general practice consultations.

Trials of computer support in primary care need to acknowledge this complexity by embedding use of the software in a carefully specified model of care. For the high quality management of chronic disease, this model will probably require subspecialisation within a general practice, as proposed in the new general practitioner contract.3

Providing focused training to key people in a practice and supporting subspecialisation through computer decision support may be a more appropriate approach to chronic disease management in primary care. Future trials of computer support must consider not only the technical features of the software …