To compare the national inpatient medication chart (NIMC) with the chart previously used at Royal Perth Hospital (RPH) in Western Australia, and with charts used at 13 other hospitals across Australia; and to audit NIMC performance in practice and to assess its design characteristics.

Audit of patient prescribing documents extended to include a comparison with aggregated pilot study data and the previous RPH chart. Assessment of design features by inspection, based on their likely effect on medication safety.

A tertiary public hospital.

Compliance with the requirements of chart fields, measured as the percentage of correct entries according to predetermined criteria as required by the WA Office of Safety and Quality in Health Care.

Average compliance was 56% (95% CI, 43%–67%). Differences in compliance after introduction of the NIMC were variable and only one was classified as “major”. The number of charts required per admission increased from 3.1 for the previous RPH chart to 6.3 for the NIMC, and chart replacement was required after 2.9 days for the NIMC compared with 5.5 days for the previous RPH chart. Of seven advantages of the NIMC claimed by the WA Director General of Health in a letter to doctors, five (71%) were not confirmed in practice. Ten notable design features of the NIMC with a potential adverse influence on medication safety were identified.

The NIMC contains adverse design features and is inferior to the medication chart previously in use at RPH. The purported advantages of introducing a national standard chart were not experienced at RPH.