Journal Scan: Laboratory requisition forms: It's all about the history

Why they did it

Laboratory requisition forms submitted to outside diagnostic laboratories often do not contain concise or pertinent clinical information, which may limit accurate interpretation.

What they did

In a recent commentary, Dr. David Pinson, Professor of Clinical Pathology at the University of Illinois, discusses the importance of providing a clinical history on laboratory requisition forms and provides tips for writing effective forms. Accurate interpretation of diagnostic tests requires an accurate history and clinical context and pathologists are “likely to agree that sample interpretation is perhaps 50% to 80% context.”

Dr. Pinson offers suggestions to ensure that requisition forms are filled out completely and consistently. These include:

• Provide complete patient information (e.g. breed, weight, age, lesion size).
• Write legibly.
• Keep highlighter use to a minimum.
• Avoid abbreviations except those that are widely understood.
• Provide a complete history.

In order to provide a thorough and informative history, Dr. Pinson recommends answering six simple questions when filling out the laboratory requisition form:

1. What is the primary reason for the evaluation? This provides an overall context for why you are seeing the patient.

2. What is the duration and frequency of the problem? When possible, provide specific parameters rather than just “acute” or “chronic.”

3. What are the objective clinical findings? Provide actual values or measurements along with changes over time if applicable.

4. What are the differential diagnoses? This will help the diagnostician understand what you are thinking.

5. What specifically was sampled? Use correct anatomic terminology.

6. What is the appearance of the tissue or lesion? This includes gross appearance or radiographic/ultrasonographic appearance.

Dr. Pinson also discusses the limitations of certain laboratory samples and the importance of sample quality in obtaining diagnostic results.

Take-home message

We’ve all heard the phrase “garbage in, garbage out” as it applies to diagnostic testing. Following these tips to provide well-written requisition forms will help enhance the diagnostic yield of all laboratory testing through better communication between the clinician and the laboratory diagnostician.

Pinson DM. Writing diagnostic laboratory requisition form histories. J Am Vet Med Assoc 2014;244:408-411.