All reliably evaluated POE systems to date have been desktop computer based, but now there is widespread use and acceptance among physicians of PDA devices for a variety of purposes. Clinicians report that drug information on a PDA improved their access to information and efficiency while reducing their self perceived error rates6. The use of these devices for information retrieval in clinical settings is expected to grow as wireless communication becomes more ubiquitous and as more applications become available6,7. During the past decade there has been a growing awareness of several issues aimed at promoting safer health care for our patients - point of care information technology is one of the keys.

To this end we have worked with a Canadian company, Drugmagnet, to develop and implement PDA-based electronic prescribing system within a major Canadian academic health centre. This is a cluster randomised trial, in which access to and use of the e-prescribing system is switched on and off for randomly chosen weeks, thus time serves as the randomized element.

Inclusion Criteria:

• active staff physician at Sunnybrook & Women's College HSC

Exclusion Criteria:

• inadequate prescribing practice (minimum number)