Accreditation is necessary but not sufficient: Case for laboratory professionalism as the differentiator of diagnostic excellence

Clinical laboratory testing influences the majority of clinical decisions regarding diagnosis, treatment, hospitalization, and discharge. Laboratory errors, which occur at rates ranging from one in 164 to one in 8,300 test results, carry significant potential for patient harm, including delayed diagnosis, inappropriate treatment, and, in extreme cases, death. Formal accreditation against internationally recognized standards, principally ISO 15189:2022, provides a structural quality management framework that reduces error risk across the total testing process (TTP). This perspective article argues that while accreditation constitutes an indispensable minimum standard for any medical laboratory, it represents a floor rather than a ceiling of diagnostic quality. Sustained excellence and clinician-valued diagnostic service require, in addition to structural compliance, a strong organizational culture characterized by intellectual staff engagement, non-punitive error disclosure, interpretive clinical partnership, and leadership commitment to quality values. Evidence consistently demonstrates that the majority of laboratory errors occur in the pre-analytical and post-analytical phases, where structural mandates are most dependent on human judgment and behavior for effective operationalization. Healthcare safety culture research shows that organizational values and shared norms, rather than procedural compliance alone, determine whether error reporting, clinical communication, and continuous quality improvement are authentically practiced. The laboratory director’s role as the primary culture architect is critically examined, along with the importance of non-punitive near-miss reporting, interpretive clinical engagement, and patient-centered quality metrics. Medical laboratories aspiring to diagnostic excellence must pursue formal accreditation as an essential structural foundation, and simultaneously invest in the cultural determinants of sustained quality: Engaged staff, transparent error learning systems, genuine clinical partnership, and leadership that consistently models the values it espouses.