Objective To explore physicians' work practices in relation to their long-term use of a computerized physician order entry system (CPOE).

Design A cross-sectional qualitative study was conducted in four clinical units in two large Australian teaching hospitals. One hospital had used CPOE for over 10 years to order all clinical laboratory and radiology tests and view test results and the other had used the computerized viewing facility of the system for over seven years with tests ordered manually. Data were collected by non-participatory observations of physicians (55 sessions) and 28 interviews.

Measurements Content analysis of the observation field notes, reflections on observations and interview transcripts were conducted by two researchers independently. A thematic grounded theory approach was used to derive key themes which would explain physicians work practices associated with CPOE use.

Results Three themes relating to physicians' established use of CPOE were identified: (1) the effect of the hospital and clinical environment; (2) changes to work practices and, (3) physicians' management of information. Physicians' test management work practices using CPOE were related to diversity between: the hospitals; the clinical units' environment, and the users of the system.

Conclusion Hospitals need to understand and analyze physicians' test management work practices prior to and during the implementation of CPOE to accommodate their diverse ways of working with computerized information systems. In the current mixed media environment, physicians' use of manual and computerized information systems for sourcing and recording information impacts on efficiency and patient safety.