Overuse of laboratory testing in hospitalized patients is a common form of low-value care and may contribute to patient discomfort, unnecessary downstream testing, inefficient use of healthcare resources, and increased costs. Although diagnostic stewardship interventions have reduced unnecessary laboratory testing in several high-income settings, evidence from Latin America remains limited, particularly regarding implementation processes and sustainability.
OPTIMIZAR is a multicenter, effectiveness-implementation hybrid type 2 study evaluating a multicomponent diagnostic stewardship intervention in internal medicine wards and intensive care units across public and private tertiary hospitals in Argentina. The intervention targets laboratory ordering practices through workflow redesign, operational support, clinician education, and audit and feedback, with local leadership teams supporting implementation at each site.
Effectiveness will be evaluated using an interrupted time series design with aggregated unit-level data collected before and after implementation. The primary outcome is monthly laboratory testing intensity, measured as Argentine Standardized Biochemical Units per occupied bed-day. Secondary outcomes include in-hospital mortality and hospital length of stay. Implementation outcomes will be assessed descriptively using the Reach, Effectiveness, Adoption, Implementation, and Maintenance framework.