Diagnostic Stewardship as a Model To Improve the Quality and Safety of Diagnosis

Diagnostic stewardship is a collaborative effort that requires building and sustaining partnerships between laboratory professionals, clinical care teams, and other experts. Practices to optimize the use of diagnostic testing are often developed around specialty- or disease-specific needs. These models and practices may be worthwhile to replicate to improve the diagnostic process for other diseases or settings. Below we review several models of team-based multidisciplinary collaboration that exemplify diagnostic stewardship.

Diagnostic stewardship in antimicrobial stewardship programs

Antimicrobial stewardship programs aim to promote optimal treatment and reduce harms to individual patients and public health (e.g., antimicrobial resistance). Whereas antimicrobial stewardship programs focus on optimizing management (e.g., reducing inappropriate prescribing of antibiotics), diagnostic stewardship works “upstream” to guide appropriate use of testing and prevent false positives and overdiagnosis.^19,71

Laboratory professionals have important roles in both antimicrobial stewardship⁷² and diagnostic stewardship, but their contributions are central in the latter.⁷¹ Laboratory professionals are essential consultants in the design of diagnostic stewardship interventions, such as:

• Policy changes related to test ordering (e.g., restrictions on repeat testing, specimen criteria).
• Modification to test ordering through required indications for use, specific order sets, CPOE templates, and computerized decision support. 
• Clinician education about test selection and interpretation.
• Staff education on appropriate specimen collection procedures, monitoring, and feedback to staff when evidence indicates that the specimen has been collected inappropriately.
• Review and periodic monitoring of “off-menu” test selection and inappropriate orders.

Diagnostic management teams

A diagnostic management team (DMT) is a practice model to assist with diagnostic test selection and interpretation to expedite accurate and timely diagnoses. The DMT is a multidisciplinary effort, often led by the laboratory with collaboration of clinical specialists and, in some cases, others such as informatics professionals. 

DMTs typically focus on a specific area of medicine. For instance, Seegmiller, et al., described a DMT for hematologic malignancies that developed several ordering protocols for bone marrow testing. They also provided a service to recommend diagnostic testing based on these protocols, patient history, and preliminary examination of bone marrow specimens. Comparing the 6 months before and 12 months after implementation of this DMT, the authors found reduced costs attributable to inappropriate testing and an increase in the percentage of positive test results. In addition, surveys of oncologists indicated that the DMT was highly acceptable and perceived as helpful.⁷³

Another report describes a DMT for coagulation disorders. Its functions included clinician education, correction of erroneous test orders, and feedback with recommendations to ordering clinicians. Longitudinal observations suggested that this DMT’s services were also associated with reduced costs and fewer erroneous test orders over time.²⁸

Pathology consultation in oncology

Although seldom described as “diagnostic stewardship,” the diagnostic process for cancer exemplifies the potential of collaboration between clinicians and diagnostic specialists (mainly pathologists) to optimize diagnostic testing. Intraoperative pathology consultation helps ensure the adequacy of biopsy specimens, confirm the diagnosis before a surgical procedure, and stage new malignancies. Pathologists also provide important diagnostic information as participants in multidisciplinary conferences, or tumor boards. 

The pathologist’s role in cancer care has expanded in the era of molecular testing and targeted therapies. Despite the essential contributions of pathologists in this setting, variable access to pathology expertise and suboptimal communication within multidisciplinary teams remain challenging in many systems. A workshop hosted by the National Cancer Policy Forum yielded several suggested solutions, including mechanisms to expand access to pathology, better integration of pathologists within the care team, and improved health IT systems.⁷⁴

Multidisciplinary genetic testing teams

The costliness and complexity of genetic testing makes genetic diagnosis a strong candidate for stewardship interventions. Board-certified genetic counselors have specialized education and training in the field of medical genetics and are available to support patients in understanding and making informed decisions relevant to their diagnosis, testing, and treatment. In some cases, these professionals serve within clincal laboratories. Genetic counselors are well positioned to serve on the frontline of stewardship initiatives in clinical genetics, as they can review incoming requests for genetic testing and provide recommendations to modify orders when appropriate.^75,76

Several examples of closer integration of diagnostic expertise with clinicians may be helpful. Zentner, et al., describe the organization of a cardiac genetics clinic attended by cardiologists, clinical geneticists, and genetic counselors.⁷⁷ A multidisciplinary approach helps ensure that genetic test results are interpreted appropriately and that patients are provided with adequate education and clinical recommendations for inherited heart conditions. 

Another example of close integration is in teams that provide rapid genome sequencing for critically ill newborns with suspected genetic diseases.⁷⁸ The complexity and time-sensitive nature of this testing require effective collaboration between geneticists and neonatal intensive care unit (NICU) clinicians and staff. Kingsmore and Cole have proposed a learning health systems model for implementing rapid whole genome sequencing in the NICU.³⁴ 

When genetic testing is used outside the context of a clinical genetics service, it is also important to have access to assistance with interpretation. For example, a liquid biopsy ordered in patients with solid tumors may reveal incidental germline mutations of clinical significance, in which case the laboratory can provide further guidance.⁷⁹

Potential for diagnostic stewardship to impact blood utilization

Diagnostic stewardship principles are important to ensure appropriate blood use because complete blood counts may be misinterpreted, leading to unnecessary blood transfusions based on test results. While inappropriate transfusion may reflect mismanagement of a correctly diagnosed patient, such incidents could also result from a diagnostic error (e.g., due to misinterpretation of complete blood count in a given clinical scenario). 

Blood utilization teams can help promote appropriate test interpretation and, hence, safer and more appropriate use of blood transfusions.^80-82 The goals of these multidisciplinary teams include reducing unnecessary resource use and limiting excess morbidity and mortality attributable to transfusions. To the extent that diagnostic error contributes to inappropriate use of transfusion, diagnostic stewardship can help advance the goals of blood utilization teams.