Randomised controlled trials (RCTs) that evaluated a RxCDSS (considered to be use of a computer to analyse patient-specific information to advise a prescriber when writing a prescription or a pharmacist when filling a prescription) were eligible for inclusion. Support had to be generated by computer, but could be delivered in any way (such as computer terminal, fax, mail, patient record insert). Only systems that intervened before a drug therapy had been chosen by a physician or that had the ability to suggest alternate therapies other than that initially prescribed by the physician were eligible for inclusion. Systems that offered "fine-tuning" advice on a predefined therapy were excluded. Systems that focused primarily on diagnosis, vaccination or nutrition were excluded. Study outcomes focused on three domains: implementation; change in health care provider behaviour; and change in patient outcomes.
Included studies evaluated RxCDSS in a number of settings; most were in an out-patient general practice or internal medicine setting. The systems addressed a variety of problems; most were in cardiovascular care and next most was general/internal medicine. A large proportion of systems were integrated with drug order entry. Control group was usual care in most trials.
Two reviewers independently selected the studies for inclusion. Any disagreements were resolved by consensus or a third reviewer.