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Test Utilization

Microbiology, Test Utilization

Clostridium difficile Two-Step Algorithm Testing

Spectrum Health Regional Laboratory is preparing to switch Clostridium difficile testing methods from solely using a molecular approach to a 2-step algorithm utilizing an Enzyme Immunoassay (EIA) that detects two C. difficile-specific proteins (glutamate dehydrogenase or GDH, and A/B toxin) with indeterminant EIA specimens reflexed to PCR (see flowchart below). It is estimated that approximately 90% of patients tested will be resolved by EIA and not require reflexive PCR testing. This algorithm decreases expenses to the patient by an average of 65% as compared to current testing without sacrificing result quality. Specimens will be batched for EIA testing at a frequency to ensure that results are available within 6 hours of receipt by the laboratory so that proper contact isolation precautions may be initiated when indicated. Continue Reading

Education & Training, Microbiology, Test Utilization

Influenza Diagnosis and Test Utilization

In anticipation of “Flu season”, it is valuable to revisit available testing methods for influenza and discuss when each test should be ordered. Though generally a self-limited infection for otherwise healthy individuals, influenza can be particularly severe for high-risk populations including infants, elderly, pregnant women, and immunocompromised hosts. Influenza incidence is largely seasonal with the majority of cases occurring between December and April of each year. Continue Reading

Microbiology, Test Utilization

Enteric Pathogens by PCR replacing Stool Culture Orderable

Effective August 18, 2016, the Spectrum Health Regional Laboratory Microbiology Department will begin offering the Verigene® Enteric Pathogens Test, a new rapid molecular test that simultaneously detects and identifies the following pathogenic enteric bacteria, viruses, and toxins that commonly cause acute community-acquired diarrhea. Testing occurs directly from stool in Cary-Blair preservative with a 1 day turnaround time (2-3 days faster than current methods). Continue Reading

Chemistry, Microbiology, Test Utilization

Changes in Reflex Criteria for “Urinalysis, do Culture if Indicated” [Update]

On September 1, 2015, Spectrum Health Regional Laboratory, in conjunction with Infectious Disease, Infection Prevention and Pharmacy, adjusted reflex criteria for urine culture based on urinalysis finding (Urinalysis, Do Culture if IndicatedTest #115, Epic #LAB348, UA CX DO IF). The adjustment involved an increase in the number of WBCs per HPF considered positive (from ≥3 to ≥10). Continue Reading

Chemistry, Education & Training, Test Utilization

Cardiac Marker Testing (Troponin)

Cardiac marker (Troponin) testing should only be ordered for Inpatient or Emergency Department patients. This test is not clinically appropriate for outpatient testing due to long outpatient test turnaround time (specimen collection to result). In cases of acute/urgent medical conditions, please have the patients evaluated at an Urgent Care center or the Emergency Department. Continue Reading

Chemistry, Referral/Sendouts, Test Utilization

Appropriate Thyroglobulin Tumor Marker and Anti-Thyroperoxidase Ordering Practices

Thyroid Peroxidase Antibody (anti-TPO), Blood Level (Test #8524 )
This is the recommended test for the evaluation of Autoimmune Thyroiditis

Thyroglobulin, Tumor Marker, Serum (Test #3069)
It is only indicated for monitoring of thyroid cancer treatment.
This result is reported with an Anti-Tg result to assess for possible interference.
This test should NOT be ordered for associated anti-Tg result provided by reference laboratory.

Thyroglobulin Antibody (anti-Tg) Test
Historically ordered with anti-TPO for evaluation of possible autoimmune thyroiditis.
The literature shows that anti-TPO, alone, has better sensitivity and specificity with only 5% of cases of Autoimmune thyroiditis with anti-TPO negative, anti-Tg positive.
Since 2/2011, requests for anti-Tg have been cancelled per Laboratory Communication: Memo Thyroglobulin Antibody 2/2011

Spectrum Health Regional Laboratory Experience February 2015 – March 2016 (13 months):
357 patients with both Anti-TPO and Anti-Tg results.
*Anti-Tg results were due to concomitantly ordered Thyroglobulin TM requests.
250 patients had positive Anti-TPO and/or Anti-Tg level
193 patients had both positive Anti-TPO and Anti-Tg level
56 patients had positive Anti-TPO and negative Anti-Tg level
1 patient had a negative Anti-TPO and positive Anti-Tg levels

Based on these results, and what is reported in the literature, we are confident of our current practices and strongly request discontinuation of Thyroglobulin TM requests for the associated Anti-Tg result

Caturegli P, De Remigis A, Rose NR. Hashimoto thyroiditis: clinical and diagnostic criteria. Autoimmun Rev. 2014 Apr-May;13(4-5):391-7