The Association for Diagnostics & Laboratory Medicine (ADLM) has summarized several of its Optimal Testing Guides into High Impact Recommendations. These actionable recommendations are geared towards hospital administrators who want to improve patient care and the bottom line. Please visit the Optimal Testing pages for each individual test for more information.
Amylase: Serum lipase is superior to serum amylase in the diagnosis and monitoring of acute and chronic pancreatitis and other pancreatic diseases. Serum amylase testing should not be offered for assessment of pancreatic disease at facilities that offer serum lipase tests. Testing for both lipase and amylase is clinically redundant, and serum amylase can safely be eliminated from laboratories that perform serum lipase testing.
CKMB: Cardiac troponin (cTnI or cTnT) testing is superior to CKMB in the diagnosis and management of acute myocardial infarction. CKMB should not be offered for assessment of acute coronary syndrome at facilities that offer cardiac troponin testing. Elimination of CKMB from the testing menu could produce financial savings without compromising patient care.
Fetal Lung Maturity: Fetal Lung Maturity (FLM) testing, assessed via Lecithin/Sphingomyelin ratio, Phosphatidylglycerol, Disaturated Lecithin, Lamellar Body Count, and Fluorescence Polarization, is not recommended in any clinical scenarios involving pregnant women to aid in timing of delivery. FLM testing should not be offered to justify preterm or early-term delivery, and there is no clinical utility of the individual tests. Elimination of FLM panels and the individual tests from the testing menu could produce significant financial savings without compromising patient care.
Homocysteine: Measurement of total plasma homocysteine is recommended in individuals with suspected or confirmed inborn errors of methionine metabolism which cause hyperhomocysteinemia. It also may be useful in the diagnosis of patients with suspected deficiencies of vitamin B12 or folate. Homocysteine should not be measured for routine screening for cardiovascular disease risk.
Serum Free Lights Chains: Measurement of serum free light chains with calculation of kappa to lambda ratio is recommended to aid in the diagnosis and/or monitoring of patients with monoclonal-protein related disorders, including multiple myeloma, Waldenstrom macroglobulinemia, and amyloidosis. Serum free light chain ratio alone is not diagnostic or confirmatory of disease, and should be interpreted in the context of other laboratory tests and clinical findings associated with monoclonal-protein related disorders.
Stool Reducing Sugars: Stool reducing sugars are used to monitor carbohydrate malabsorption in children with short bowel syndrome to differentiate the source of diarrhea and to screen for disaccharidase deficiency. It may detect unabsorbed carbohydrates in stool after enteral feeding changes when osmotic diarrhea worsens. It is not appropriate for diagnosing lactose intolerance, necrotizing enterocolitis, or acute diarrheal illness, and it should not be used in adults due to poor sensitivity/specificity, pre-analytical issues, and superior alternatives. Note that the test requires a fresh, liquid stool sample.
Total Thyroxine: Current relevant guidelines recommend against the routine use of Total Thyroxine (TT4) for screening thyroid dysfunction in non-pregnant, asymptomatic adults. The preferred practice is a Thyroid stimulating hormone (TSH) with reflex to Free T4 (FT4). TT4 is frequently confounded by variations in thyroid-binding proteins caused by medications (e.g., oral contraceptives), liver disease, or acute illness. The primary remaining clinical utility for TT4 is during the later stages of pregnancy, where it serves as a more reliable proxy than FT4 (using pregnancy-specific reference ranges), and in specific cases where TSH and FT4 results are discordant or when monitoring certain specialized treatments.
Vitamin B12 or cobalamin: Vitamin B12 should not be ordered for routine screening in asymptomatic, average risk individuals. Measurement of serum vitamin B12 is recommended only in high-risk individuals who have at least one risk factor (e.g., malabsorptive conditions, prolonged metformin use, long-term acid-suppressing therapy, vegan diet, advanced age >75 years, or alcohol use disorder) and at least one clinical feature of deficiency (e.g., megaloblastic anemia, neuropsychiatric symptoms). American Gastroenterological Association recommends yearly screening for patients with ileal resection >30 cm or extensive Crohn disease, and the American Diabetes Association recommends periodic assessment every 1-2 years for patients on long-term metformin. Borderline or indeterminate vitamin B12 levels warrant confirmatory methylmalonic acid measurement. Definitive diagnosis of pernicious anemia requires additional investigations including intrinsic factor antibody testing.
Vitamin D: Nointer/national medical association recommends population-wide screening for hypovitaminosis D. With sensible sun exposure, ingestion of foods fortified with vitamin D and supplementation, most individuals achieve the recommended 25(OH)D concentrations (≥20 ng/mL) for effective calcium absorption and metabolism. Historically, promotion of supplementation and increased testing has been attributed to the enthusiastic reporting of the potential health benefits of vitamin D in the lay media based on epidemiological risk-association studies that have not been supported in subsequent randomized control trials.
The U.S. Preventive Services Task Force (USPSTF) and Endocrine Society do not recommend routine screening for asymptomatic adults but suggest testing for older adults (≥70 years) with risk factors. The American Academy of Pediatrics (AAP) recommends vitamin D testing for infants and children with risk factors such as limited sun exposure, dark skin, or certain medical conditions, but routine testing is not advised for adolescents and young adults.
Before making any changes, administrators should consult their laboratory director to make sure the changes are right for their patient population.