Improving Utilization of Pathologist Reviewed Blood Films

Peripheral blood films are a daily practice in any hematology laboratory. Peripheral blood films are reviewed by a laboratorian via manual differential. In select instances, a laboratorian will request that a pathologist review the peripheral blood film. Common industry practice also allows any provider to directly order a pathology review of a peripheral blood film, bypassing established reflex criteria. 

However, unrestricted ordering of peripheral blood reviews from a pathologist increases use with reduced clinical benefit, increases wasted cost, and leads to inefficient use of resources. Luckily, implementing a layered mitigation strategy with measured outcomes can improve the use of this precious resource. 

What are peripheral blood films?

Peripheral blood films (PBFs) start with the application of peripheral blood to a glass slide, followed by staining and microscopy review. This resource intense procedure is performed by a trained and competent laboratorian. The purpose is to observe, count, differentiate, and categorize platelets, red blood cells, and white blood cells. PBFs are beneficial to providers, aiding in the differentiation of infection, inflammation, nutritional deficiency, etc. 

Individual competency in this procedure requires rigorous weeks (or months) of training. Even still, many laboratorians lack the expertise necessary to correctly classify all the abnormalities encountered in today’s era of oncologic medicine. With good policies and practices, laboratorians can identify which blood films require additional interpretation and differentiation by a skilled pathologist, negating the need for provider-based orders.

Why do pathologists review peripheral blood films?

Slides identified for review often elicit certain features that the laboratory categorizes in policy format as significant, therefore requiring input from a pathologist. Features requiring review by a pathologist may include the following:

• Presence of blasts exceeding threshold
• Absolute lymphocytosis
• Presence of hairy cells
• Lymphocytes with hyper condensed nuclear chromatin in undiagnosed lymphoma
• Lymphocytes with lobulated or flower-like nucleus
• Myeloid cells with features characteristic for myeloid dysplasia or myeloproliferative neoplasm
• Lymphoblasts or Prolymphocytes
• Cellular inclusions suggestive of Ehrlichia, Anaplasma, or Babesia spp.
• Absolute basophilia
• Sickle cells
• Select cytopenias
• Select cases of anemia

Ultimately, the pathologist will provide an interpretation of the findings, suggestions for additional laboratory tests, and a differential diagnosis.

Why are provider-ordered pathology reviews problematic?

Within the US healthcare system, providers have open access to all laboratory test orders, including pathology blood smear reviews. Additionally, the care teams for those providers have similar access to laboratory test orders. With no measures to restrict access, our health system has observed a steep increase in requests for pathology reviews. 

Clinician driven orders for pathology reviews provide little clinical value—reviews are labor intensive and, if not clinically indicated, may add no clinical value while unnecessarily increasing workloads with diminutive financial coverage.¹ In a labor constrained department concerned about rising costs, our laboratory at Bellin Memorial Hospital prioritized utilization improvement of pathology PBF reviews.

The Plan-Do-Study-Act model

Plan-Do-Study-Act (PDSA) is a way to assess the effect of implemented changes. As the name implies, PDSA is a simple four-stage model used to measure how implemented changes are impacting a process and then act on those findings. PDSAs are an effective tool to measure and act on utilization improvements of pathology reviews.

Over approximately 14 months, our laboratory used the PDSA method to measure the effects of six interventions related to pathology smear reviews. Each intervention showed various levels of effectiveness, spurring the next sequential change.

1. Updated guidelines

Pathology PBF reviews provide important interpretive information to primary care providers, helping them differentiate a diagnosis. Often, this information is enough for primary care to manage a patient’s care plan without further consultation. However, some cases require a referral to Hematology/Oncology.

As our first change, Oncology and Pathology developed care guidelines that included recommendations of select laboratory tests to primary care. We removed the pathology PBF review from several indications and highlighted it as a generally unnecessary order from primary care.

2. Provider presentation 

While reviewing the care guidelines, we realized that many providers were unaware of more recent technological advances in hematology. Similarly, several providers were unaware of the level of technical expertise within the laboratory or the manual slide review performed by a laboratorian.

With this knowledge, our team created an educational presentation that covered the following:

• Use and availability of updated care guidelines
• Technical expertise of modern workforce
• Technical advances in hematology instrumentation
• Rules/reflex driven algorithms
• Pathology specific criteria determines need for pathology review

This presentation was shared with primary care, who were predominantly driving the increase in unnecessary pathology reviews. Many providers were open about their lack of awareness of the modernization of the hematology laboratory.

Though initial improvements resulted in fewer requested reviews, there was still more work to be done—we found that implementing soft changes, such as updating a care guideline that may never be reviewed or presenting new information to an abbreviated care team with the expectation that the information would be shared among care teams, was not enough. At the same time, entirely removing the orderable test is also an ineffective solution. Instead, sustainable change is best achieved by guiding providers to the right decision. But building an electronic solution that guides without being obtrusive can be complicated.

3. Adding guardrails: LIS order questions

Working with the hematology laboratory and Pathology, an order question was developed and built into the pathology review orderable. Answering this question is mandatory and requires providers to select an indication or provide a free text entry when criteria are not met to justify ordering a pathology review.

This design prompts the user to pause and consider if the test is appropriate. In addition, the recently revised care guidelines are linked in the orderable, providing ordering personnel with the opportunity for review and consultation during the ordering process.

4. Provider preference lists 

Provider preference lists are an abbreviated list of tests or other orderable diagnostics displayed to a provider. These lists are often created at the start of a provider’s employment and may never be further reviewed.

With help from IT, our laboratory identified providers that had the pathology smear review on their preference list and correlated this with more frequent ordering patterns. Using this data, we spoke with providers to better understand their use of the reviews. For examples, some providers didn’t want or need the pathology review on their preference list but had added it as they had mistaken it for the manual differential performed by a laboratorian.

5. Test synonyms

Discoveries about test name confusion led our team to examine the impact of search synonyms. In this case, inadvertent test findings would come up when searching for the laboratorian-performed manual differential.

Through a simple process of plugging in similar keywords into the ordering system, we discovered several that linked directly to the pathology review, e.g., both “smear” and “peripheral” were linked directly to the pathology smear review. This can cause problems when the person ordering, such as an RN, LPN, or other less laboratory-savvy healthcare professional, may not realize that a manual differential can also be called a peripheral blood film review.

Recognizing that a pathology smear review is different than a laboratorian-performed manual differential should not fall to RNs or other healthcare professionals. We implemented a simple IT fix to remove “smear” and “peripheral” as synonyms to the pathology smear review, and instead, linked these words to the laboratorian-performed manual differential.

6. Test names

Naming a laboratory test is not without consequence.² Test names should clearly define the test being performed, potentially including the methodology, as ambiguity can lead to performing an incorrect test or incorrect test interpretation. Consider the recent SARS-CoV-2 pandemic and the implications of only naming a test “SARS-CoV-2,” which could be an antigen, antibody, or NAA-based test, each of which serves a different purpose, spanning initial infection, active reinfection, or past infection. 

Through discussions with the hematology laboratory and Pathology, our health system renamed “Pathology Smear Review” to “Pathologist Consult (aka Pathology Smear Review)” to reflect the true nature of the order: Frequently, in addition to performing a manual differential and assessment of the PBF, pathologists also review pertinent patient history and lab results to provide a differential diagnosis without ever assessing a patient at the bedside. Thus, now having “consult” as part of the test name helps clarify that this order is a consultation on a patient.

Opportunities for change

Pathology consults on PBFs are not typical laboratory tests, earning more attention and scrutiny regarding appropriate test utilization. Through all the implemented changes, data was reviewed and shared with the hematology laboratory and Pathology teams. We followed a Plan-Do-Study-Act process of planning a change, implementing the change, studying the outcome, and identifying further actions. What we learned along the way helped us identify the next opportunities for change: Offering provider education via care guidelines and presentations helps promote more effective utilization in the short term; Leveraging capabilities within the electronic ordering system provides sustained improvements without being overly intrusive to daily workflows; Changing test names, adding order questions, and improving search synonyms are easy to implement and show high success in improving utilization of pathology consults on peripheral blood films.

References:

1. Beckman AK et al. Clinician-ordered peripheral blood smears have low reimbursement and variable clinical value: a three-institution study, with suggestions for operational efficiency. Diagn Pathol. 2020;15(1):112. doi:10.1186/s13000-020-01033-8
2. Carter AB et al. Laboratory test names matter: a survey on what works and what doesn't work for orders and results. Arch Pathol Lab Med. 2024;148(2):155-167. doi:10.5858/arpa.2021-0314-OA