Low-value use of procalcitonin testing after introduction at an academic medical center

From the 2018 HVPAA National Conference

Gregory Seymann (University of California San Diego Division of Hospital Medicine), Christina Lin (University of California San Diego School of Medicine), Catherine Firestein (University of California San Diego Division of Hospital Medicine), Bryan Huang (University of California San Diego Division of Hospital Medicine)

Background

Procalcitonin (PCT) is a biomarker that correlates with the presence of bacterial infection in certain clinical scenarios; it has increasingly accepted indications for antibiotic stewardship.

Objectives

Shortly after introduction of the PCT assay at our large academic medical center, we sought to examine prevalence and appropriateness of use.

Methods

Rapid-turnaround PCT assay was introduced at our 808-bed tertiary care academic medical center in April 2017. Three months after the test became available, we performed a retrospective chart review of all inpatients with at least 1 PCT assay performed during their hospital stay. Data on test indication, antibiotic use, and PCT value was abstracted. Indications for testing were classified as use for either diagnosis or de-escalation.

Antibiotic de-escalation was defined as discontinuation of antibiotics when PCT values dropped below 0.25.

Most sources suggest that antibiotics should be considered for patients with suspected infection and PCT values ≥ 0. 25-0. 5 ng/ml; conversely, clinicians should consider withholding antibiotics for patients with PCT values < 0. 25.  Antibiotic use was defined as concordant with PCT if antibiotics were started for values ≥ 0.25 or withheld for values < 0.25; otherwise, antibiotic use was considered discordant.

In addition, reviewers made a clinical judgment as to whether the application of the PCT test added value to the patient care. To be deemed high-value, the reviewers sought chart evidence that the treating team applied the test result to the care of the patient in a manner consistent with current guidelines and evidence.

Results

Data from 205 unique patient encounters between July and September 2017 was abstracted, encompassing 374 separate PCT tests. 50. 0% of initial PCT values were ≥ 0. 25, with 32. 2% > 0. 5. Mean (SD) initial PCT level was 3. 76 (21. 43), with a range of 0. 02-247; median initial PCT was 0. 23. PCT was overwhelmingly used for diagnosis (76. 2%) rather than de-escalation (8. 4%); the remainder of tests were for unclear indications. Respiratory symptoms (38. 1%) and sepsis (33. 5%) were the dominant clinical indications for testing. In 36 cases (17. 5% of the sample), PCT was used for indications lacking established evidence, such as cellulitis, UTI, leukocytosis, gastrointestinal infections, and nonspecific infectious syndromes.

In our sample, 31. 7% of patients had antibiotic use discordant with the PCT value; 86. 2% of the discordant use involved patients continued on antibiotics despite a low PCT. Based on reviewers’ clinical judgment, 62. 2% of the PCT use was felt to be low-value.

Conclusion

Low-value and non-evidence based use of serum PCT testing was frequent shortly after its introduction at a large tertiary-care academic medical center. As the availability of this biomarker grows more prevalent, attention to appropriate implementation strategies is important to ensure high-value application.

Implications for the Patient

Introduction of a new test or procedure without accompanying education, training and point-of-care guidance on use may increase the rates of inappropriate utilization.  Efforts to improve on these components at our institution are underway