To the Editor: We would like to add our perspective to the discussion on computerised prescribing.1 Electronic prescribing with appropriate decision support is recognised by the Medication Safety Taskforce of the Australian Council for Safety and Quality in Health Care as a key initiative to prevent patient harm.2 Such systems reduce the opportunity for prescribing errors and improve patient safety.3

The widely espoused benefit of the clarity and legibility associated with electronic prescribing appears to have led many to assume that electronic prescribing is an essential component of medication safety systems whether or not it includes a decision support system.

In fact, electronic prescribing without decision support has been associated with an increase in the incidence of error4 and inappropriate use of medications.1

A computer-generated discharge summary was developed at a tertiary referral teaching hospital in Brisbane. With this system, a discharge prescription was generated using information entered from the database by the medical officer.

As part of standard practice, a pharmacist reviews all discharge prescriptions and compares them with the inpatient medication chart, discussing any apparent errors with the medical officer. We conducted an audit of 200 consecutive medical discharge prescriptions (100 generated by computer and 100 handwritten) in mid-2001. The errors detected are summarised in the Box. The same medical staff were responsible for both types of prescriptions. Significantly more errors in prescribing were noted for the computer-generated prescriptions than for the handwritten scripts (P < 0.001). The proportion of errors with potential for harm was similar in both groups.

Three specific types of error occurred more frequently with electronic prescribing. We can speculate that dosing errors occurred when previous discharges were copied and the previous dose was continued, duration errors occurred as a result of a computer default to 10 days’ therapy, and the continuation of drugs not required for discharge resulted from copying previous medication records and not reviewing the current drugs prescribed.

This uncontrolled observational audit demonstrated that electronic prescribing without decision support in busy medical wards can significantly increase the risk of patient harm when compared with the handwritten system. The discharge prescription component of this system was withdrawn on the basis of this audit, and the paper-based system reinstituted until a safer alternative becomes available.