Deciphering reference intervals and clinical decision limits in equine endocrine diagnostic testing

Critical Results in Laboratory Medicine

BACKGROUND

Timely and accurate notification of critical results is crucial in laboratory medicine and mandated by accreditation standards like ISO15189. Alert lists do, however, vary widely and clinical laboratories typically rely on a combination of in-house agreed and/or literature-based critical values. Communication by phone is still the preferred method of notification, but digital communication could help improve communication of critical results.

CONTENT

We review the available evidence concerning critical result thresholds and critical result notification practices. The evidence is ranked using an adaptation of the Stockholm Hierarchy. In addition, we propose an evidence-based list of critical result thresholds for hospitalized patients that laboratories can use as a starter list and further customize based on the clinical needs of their patient population.

SUMMARY

A clear distinction between critical results and significantly abnormal results is essential for effective and timely healthcare interventions. Implementation of a policy using differentiated thresholds taking into account individual patient characteristics and how fast medical attention is needed, and the use alternative communication methods could enhance communication efficiency and reduce notification fatigue.

Factors affecting measurement of basal adrenocorticotropic hormone in adult domestic equids: A scoping review

Measurement of basal adrenocorticotropic hormone (ACTH) concentration is the most commonly used diagnostic test for pituitary pars intermedia dysfunction (PPID). Although several pre-analytical and analytical factors have been reported to affect basal ACTH concentrations in equids, the extent to which these have been evaluated in the context of PPID diagnosis is unclear. The objectives of this scoping review were to identify and systematically chart current evidence about pre-analytical and analytical factors affecting basal ACTH concentrations in adult domestic equids. Systematic searches of electronic databases and conference proceedings were undertaken in June 2022, repeated in October 2022 and updated in August 2023. English language publications published prior to these dates were included. Screening and data extraction were undertaken individually by the authors, using predefined criteria and a modified scoping review data extraction template. After removal of duplicates, 903 publications were identified, of which 235 abstracts were screened for eligibility and 134 publications met inclusion criteria. Time of year, exercise, breed/type and transportation were the factors most frequently associated with significant increases in ACTH concentration (n = 26, 16, 13 and 10 publications, respectively). Only 25 publications reported inclusion of PPID cases in the study population, therefore the relationship between many factors affecting basal ACTH concentration and diagnostic accuracy for PPID remains undefined. However, several factors were identified that could impact interpretation of basal ACTH results. Findings also highlight the need for detailed reporting of pre-analytical and analytical conditions in future research to facilitate translation of evidence to practice.