Background <p>Healthcare overuse is a widespread issue, accounting for approximately 10–30% of total healthcare costs. This study examines the impact of a computerized alert system designed to reduce inappropriate laboratory tests across five public hospitals in southern Switzerland.</p> Methods <p>A 32-month observational study - between July 2021 and March 2024 - was conducted to assess the effectiveness of the alert system in discouraging unnecessary laboratory testing. Data were collected from five public hospitals where 12.4% of laboratory tests performed were identified as non-compliant with recommended minimal retesting intervals (MRI). Of these non-compliant tests, 11.4% were prevented by the alert system, indicating direct intervention efficacy.</p> Results <p>Distinct patterns in alert acceptance rates emerged over time. Hospital H4 showed a significant increase in alert acceptance, which may reflect contextual factors such as a work environment promoting open communication and kindness among healthcare professionals. Conversely, hospitals H1 and H5 experienced declining alert acceptance, likely due to habituation effects. A learning effect was suggested by a significant reduction in inappropriate tests for certain markers, such as C-Reactive Protein (CRP), over time. Following the alert’s implementation, the average rate of appropriate prescriptions across all hospitals was 87.5%. Specific tests, including PSA (19.4%), PTH (15.5%), ammonia (14.8%), and CRP (14.5%), had higher alert acceptance rates. The cost savings from avoided tests were estimated at EUR 1,642,417.</p> Conclusions <p>This study confirms that computerized alerts represent a gentle, effective and cost-efficient method to reducing overtreatment, increasing awareness among healthcare professionals, and supporting personalized medicine. The findings suggest: hypothetically - that organizational environments fostering human-centered care, effective communication and kindness may enhance the impact of alert systems, warranting further empirical investigation.</p> What is known on this topic <p><UnorderedList Mark="Bullet"> <ItemContent> <p>Overmedicalization accounts for 10–30% of healthcare costs, representing a significant concern in health resource management.</p> </ItemContent> <ItemContent> <p>The Minimum Repeat Interval (MRI) defines appropriate time at which a laboratory test can be repeated to minimize potentially unnecessary ones.</p> </ItemContent> <ItemContent> <p>Alerts in computerized medical records, indicating tests prescribed within the MRI, can effectively reduce unnecessary testing, especially when combined with other interventions.</p> </ItemContent> </UnorderedList></p> What this study adds <p><UnorderedList Mark="Bullet"> <ItemContent> <p>This study demonstrates that laboratory alerts based on MRI effectively reduce overtreatment, enhancing personalized medicine, with unique data from 929,808 tests over 32 months.</p> </ItemContent> <ItemContent> <p>Alert compliance and appropriateness vary by test type, showing greater effectiveness for tests with higher risk of being inappropriately prescribed (e.g. CRP).</p> </ItemContent> <ItemContent> <p>Hypotheses are proposed regarding the potential influence of organizational culture - particularly environments promoting kindness - on the effectiveness of behavioral nudges.</p> </ItemContent> </UnorderedList></p>