Objective: To compare the effects of computerized and paper-based versions of guidelines on recently qualified physicians' consultation practices.

Methods: Two arm cluster randomized controlled trial. Physicians were randomized to receive computerized or textbook-based versions of the same guidelines for a 4-week study period. Physicians' compliance with guideline recommendations about laboratory, radiological, physical and other examinations, procedures, nonpharmacologic and pharmacologic treatments, physiotherapy, and referrals were measured by case note review.

Results: There were 139 recently qualified physicians working in 96 primary healthcare centers in Finland who participated in the study. Data on 4,633 patient encounters were abstracted, of which 3,484 were suitable for further analysis. Physicians' compliance with guidelines was high (over 80% for use of laboratory, radiology, physical examinations, and referrals). There were no significant differences in physicians' consultation practices in any of the measured outcomes between the computerized and textbook group.

Conclusion: Guidelines are a useful source of information for recently qualified physicians working in primary care. However, the method of presentation of the guidelines (electronic or paper) does not have an effect on guideline use or their impact on decisions. Other factors should be considered when choosing the method of presentation of guidelines, such as information-seeking time, ease of use during the consultation, ability to update, production costs, and the physicians' own preferences.