Computerised log files are important for analysing user behaviour in health informatics to gain insight into processes that lead to suboptimal user patterns. This is important for software training programmes or for changes to improve usability. Technical user behaviour regarding decision aids has not so far been thoroughly investigated with log files. The aim of our study was to examine more detailed user interactions of primary-care physicians and their patients with arriba-lib, our multimodular electronic library of decision aids used during consultations, on the basis of log data. We analysed 184 consultation log files from 28 primary-care physicians. The average consultation time of our modules was about 8 min. Two-thirds of the consultation time were spent in the history information part of the programme. In this part, mainly bar charts were used to display risk information. Our electronic library of decision aids does not generate specific user behaviour based on physician characteristics such as age, gender, years in practice, or prior experience with decision aids. This supports the widespread use of our e-library in the primary-care sector and probably beyond.