To evaluate whether a brief educational intervention for junior medical officers (JMOs) could reduce inappropriate repeat glycated haemoglobin (HbA1c) testing (defined as testing within 90 days of a prior result without clinical indication) in the Acute Medical Unit (AMU) at Royal Perth Hospital.

We conducted a retrospective before and after audit of HbA1c orders in the AMU. The pre-intervention period included all inpatients admitted from 1 December 2024 to 28 February 2025, and the post-intervention period included admissions from 1 March to 1 June 2025. The intervention comprised a 20-minute PowerPoint session delivered at JMO orientation, supported by reminder posters in doctors’ offices. The primary outcome was the proportion of inappropriate HbA1c orders. Secondary analysis examined distributions of inter-test intervals using box plots. Differences in proportions were analysed with Chi-square tests.

A total of 270 HbA1c orders were analysed, including 187 pre-intervention and 83 post-intervention. Inappropriate repeat testing decreased from 39.6% pre-intervention to 36.1% post-intervention (absolute reduction 3.5 percentage points; relative reduction 8.8%; p = 0.69). Box plots showed similar medians and interquartile ranges across periods, indicating limited sustained change in ordering behaviour.

A single low-cost educational intervention led to a modest, statistically non-significant reduction in inappropriate HbA1c testing. More robust strategies such as audit and feedback cycles, electronic clinical decision support, and structured feedback from JMOs may be required to achieve meaningful reductions in low-value testing. These approaches align with Choosing Wisely principles and international guidance on optimizing resource use.