Background: The Minnesota Lab Appropriateness (MLAB) criteria were developed for assessing appropriateness of complete blood counts (CBCs) and serum electrolyte panels (SEPs) ordered for adult inpatients.
Methods: Two independent raters used the MLAB criteria to rate appropriateness of labs ordered during 50 hospitalizations through retrospective medical record review.
Results: Evaluation of 208 CBCs and 253 SEPs on a 2-category scale (appropriate/inappropriate) resulted in an inappropriate lab rate of 24% and 25% for CBCs and SEPs, respectively. Using a 3-category Likert scale that included an "equivocal" rating to allow for clinical uncertainty, 17% of CBCs and 20% of SEPs were considered inappropriate. Interrater reliability was "substantial" using the dichotomous scale for both CBCs and SEPs. Using the 3-category Likert scale, reliability was "substantial" for CBCs and "moderate" for SEPs.
Conclusion: The MLAB criteria identified inappropriate labs at a rate consistent with published figures, with good interrater reliability.