Introduction

Overutilization of laboratory tests is a significant challenge in the U.S. healthcare system, leading to excessive costs and potential patient harm. A landmark study published in the Archives of Pathology & Laboratory Medicine, titled “Inappropriate Laboratory Testing: Significant Waste Quantified by a Large-Scale Year-Long Study of Medicare and Commercial Payer Reimbursement,” analyzed approximately 1 billion outpatient test claims from 2019. The study critically examined four commonly ordered tests—25-hydroxy vitamin D, PSA, lipid panels, and HbA1c—and found that 7% to 51% of these tests were conducted more frequently than recommended, resulting in over $350 million in unnecessary expenses.

Detailed Findings

The study analyzed billing records from Medicare and commercial insurance payers, covering 232 million people, which makes it one of the most comprehensive studies on laboratory test utilization to date. The four tests analyzed represent a significant portion of the overall test volume, each with specific clinical indications:

Hemoglobin A1c (HbA1c) Testing:

• Overuse: The study found that 28% of patients were tested more frequently than recommended, with a subset tested monthly. Guidelines suggest biannual testing for stable diabetic patients and quarterly for those with poor glycemic control.
• Implications: Over-testing HbA1c can lead to unnecessary treatment changes and increased patient burden without significant clinical benefit.

Lipid Panel Testing:

• Overuse:5% of patients were tested more than once a year, with some receiving as many as 12 tests annually. Guidelines typically recommend testing every 4 to 6 years for individuals at low cardiovascular risk.
• Implications: Excessive lipid testing can lead to unnecessary medication adjustments and follow-up appointments, adding to healthcare costs without improving patient outcomes.

Prostate-Specific Antigen (PSA) Testing:

• Overuse:1% of patients received PSA tests more frequently than recommended, with some tested more than three times a year. Guidelines generally recommend annual testing or less, depending on risk factors.
• Implications: Frequent PSA testing can lead to overdiagnosis and overtreatment, particularly in older men, where the risks of aggressive treatment may outweigh the benefits.

25-Hydroxy Vitamin D Testing:

• Overuse: Approximately 18.3% of patients were tested more than once a year, despite guidelines suggesting that a single annual test is adequate for most patients. Some patients were tested as often as monthly.
• Implications: Over-testing not only increases costs but may lead to unnecessary follow-up interventions, contributing to patient anxiety and potential harm.

Methodology and Analysis

The study employed a retrospective analysis of 2019 claims data, comparing the frequency of these tests against established clinical guidelines from sources such as the American Diabetes Association and the U.S. Preventive Services Task Force. The conservative approach used in the study ensured that the estimates of overuse were not inflated. Even with this conservative estimation, the findings indicate that nearly a quarter of the patients tested underwent unnecessary testing.

The researchers calculated the financial impact of this overuse by applying Medicare reimbursement rates to the excess tests. The study estimated that Medicare alone incurred between $1.95 billion and $3.28 billion in direct excess expenses due to unnecessary testing in 2019. This does not include the hidden costs associated with downstream care, such as follow-up tests and procedures that arise from overdiagnosis.

Discussion

The study reveals significant overutilization of four common laboratory tests, with Hemoglobin A1c (HbA1c) being the most overused. A staggering 28% of patients received more frequent testing than recommended, with 1.7% undergoing more than five tests annually, leading to $103.6 million in excess costs. Following this, the lipid panel test was also overused, with 23.5% of patients receiving more than one test per year, contributing to $117.9 million in unnecessary expenses. Vitamin D and PSA tests, while also overordered, had slightly lower rates of overutilization but still resulted in millions of dollars in excess healthcare spending.

Diabetes affects an estimated 38.1 million adults in the United States and was responsible for approximately 409,000 deaths in 2019. Given the severity of this disease, proper monitoring is crucial. The Centers for Disease Control and Prevention (CDC) recommends an HbA1c test every three years for nondiabetic individuals. For diabetics with stable glycemic control, the American Diabetes Association (ADA) advises biannual HbA1c testing, while those undergoing therapy adjustments or struggling to meet glycemic goals should be tested quarterly. Adhering to these guidelines can ensure effective management and reduce the risk of complications.

Cardiovascular disease remains the leading cause of death in the United States, with 720,000 new and 335,000 recurrent coronary events reported in 2019. Cholesterol and lipid testing are essential tools for assessing cardiovascular risk. The 2018 American College of Cardiology/American Heart Association guidelines recommend cholesterol level checks every 4 to 6 years for healthy adults, with more frequent testing for those at higher risk. Medicare (CMS) covers one lipid panel annually but permits more frequent testing of individual components for patients on lipid-lowering medications, reflecting the importance of tailored monitoring in high-risk populations.

Prostate cancer is the third leading cause of cancer deaths in the United States, with approximately 224,000 new cases in 2019. Screening guidelines for prostate cancer, particularly using PSA testing, vary widely. The American Cancer Society recommends annual PSA testing for men over 50, and for those aged 40–45 in high-risk groups. The US Preventive Services Task Force advises annual testing for men aged 55–69 but not for those over 70, due to the higher risk of death from other causes. CMS aligns with annual testing for men over 50, while the American Urology Association suggests a maximum interval of every two years for PSA testing. These varying guidelines reflect the complexity of balancing early detection with the risks of overdiagnosis and overtreatment in prostate cancer management.

The US Preventive Services Task Force found insufficient evidence in both 2015 and 2021 to recommend routine screening for vitamin D deficiency in asymptomatic adults, leading some commercial payers to stop covering such tests. However, CMS guidelines recommend testing for individuals with one of 29 high-risk conditions but limit this to no more than three tests per year, even in these populations. Despite concerns about deficiency, only about 10% of the population is actually deficient, with guidelines for the remaining 90% ranging from zero to one test annually. This highlights the need for targeted testing rather than routine screening for all.

Conclusion

The study highlights significant overutilization of four common laboratory tests—Hemoglobin A1c, lipid panels, PSA, and vitamin D—resulting in unnecessary healthcare costs and potential patient harm. The discussion emphasizes the need for strict adherence to established testing guidelines to reduce overtesting. The study recommends limiting testing frequency based on clinical guidelines: twice per year for stable diabetics for HbA1c, every 4-6 years for lipid panels in low-risk individuals, annual PSA testing, and up to three vitamin D tests per year for high-risk patients.

The study also acknowledges limitations, including the retrospective design, which may introduce bias, and the focus on specific tests, which might limit generalizability to other tests or populations. The authors suggest that improved implementation of testing protocols and continuous monitoring could help mitigate these issues, ultimately leading to better resource utilization and enhanced patient care.

References

• Smart, D., Schreier, J., & Singh, I. R. (2024). Inappropriate Laboratory Testing: Significant Waste Quantified by a Large-Scale Year-Long Study of Medicare and Commercial Payer Reimbursement. Archives of Pathology & Laboratory Medicine. DOI: 5858/arpa.2023-0486-OA.