The implementation of electronic clinical decision tools to reduce inappropriate urine and swab requests: A diagnostic stewardship intervention to reduce the environmental impact of laboratory testing

Background The NHS accounts for approximately 4–5% of England’s total carbon footprint and was the first healthcare organisation to commit to a net-zero target. Reducing the inappropriate use of diagnostic tests could play a meaningful role in reaching this goal. In 2024, the microbiology laboratory at Lancashire Teaching Hospitals NHS Foundation Trust received >90,000 urine and >15,000 wound samples. Local audit data highlights samples are sent for testing in the absence of clinical signs and symptoms of infection. Furthermore, 25 % of superficial swabs and 10% of urines grew mixed-faecal organisms. Purpose The aim was to implement a diagnostic stewardship intervention to reduce inappropriate urine and wound swab submissions from primary care and estimate associated carbon savings. Research Design A pre-analytical stage diagnostic stewardship intervention was implemented consisting of a computerised clinical decision support tool (CCDS). The tool prompts clinicians, using evidence-based guidance, on when to obtain samples for testing. Study Sample: 3-month intervention period data was compared with two 3-month pre-intervention periods (I and II). Data Analysis The UK Government 2024 greenhouse gas conversion factors were used to calculate the total CO 2 e associated with testing urine and wound samples. Results Comparing number of samples received during the intervention period with pre-intervention II, urine samples decreased by 10.2%, saving 190.5 kg CO 2 e. Similarly, wound samples decreased by 12.9%, saving 80 kg CO 2 e. Conclusion The CCDS tool effectively reduced unnecessary testing and associated carbon emissions, supporting the NHS’s net-zero ambitions. Similar tools can be employed in other areas of pathology to reduce the impact of inappropriate testing whilst supporting sustainable healthcare.