The effect on medication errors of pharmacists charting medication in an emergency department.

Objective: To determine the frequency and clinical significance of medication errors when (a) pharmacists elicit medication histories in the Emergency Department after medications have been prescribed by doctors and (b) pharmacists obtain and chart medication histories prior to doctors' approval.

Setting: The Queen Elizabeth Hospital, a 350 bed South Australian teaching hospital, serving the local adult community.

Method: Emergency Department patients at risk of medication misadventure were recruited in two phases with a 'usual practice' arm (6 weeks) and a 'pharmacist medication charting' arm (5 weeks) reflecting an alternative intervention.