Volume 40 Number 4 | August 2026
Summary

The article discusses the commonly cited claim that 70 percent of medical decisions are based on laboratory results, tracing its origin to a 1996 article without direct evidence. The author highlights recent studies showing varied percentages and methodological challenges in substantiating this claim, ultimately advocating for citing verifiable data about the profession, such as workforce size, test volumes, and testing sites, to better represent medical laboratory professionals’ value in healthcare.

Tracey K. Gardner, MSEd, MLS(ASCP)CM, Volunteer Contributor

Tracey GardnerThe assertion that 70 percent of medical decisions are based on laboratory results is common lore among medical laboratory professionals. It permeates our social media celebrations and state proclamations during Medical Laboratory Professionals Week and in professional promotion presentations and written articles. I also previously included it in my advocacy, recruitment, and outreach activities and presentations because it presents a plausible sounding concrete number and is quoted on the websites of both the Centers for Disease Control and Prevention (CDC)1 and World Health Organization (WHO).2

As my outreach and recruitment activities increased in the early 2020s, I decided it was time to track down a citable reference for this statement. What I found changed the way I promote the value of laboratory medicine.

The “70 percent claim” originated from a 1996 article by Rodney W. Forsman, where he states, “We know that, although the laboratory represents a small percentage of medical center costs, it leverages 60-70 percent of all critical decision-making, e.g., admission, discharge, and drug therapy,”3 without providing direct evidence. Rather, Forsman relied on personal communication with colleagues about shared observations on use of laboratory data in making medical decisions.4

Researchers have sought to substantiate the true value of laboratory results in healthcare decision making over the last 10 years. Doing so has proved nuanced and complex, relying on how the study defines and measures “decision making” and limiting the ability to generalize findings.

“As medical laboratory professionals, we contribute to evidence-based and data driven care and, as such, I urge all of us to cite accurate and verifiable data better representing the profession in our advocacy and outreach activities.”

For example, a 2016 study involving cardiology and oncology physicians in the United States and Germany found 66 percent of medical decisions were based on laboratory testing, but the research design relied on physician perceptions measured through responses to survey and interview questions, not empirical data.5

A study published in 2017 used the number of laboratory tests ordered per healthcare encounter as a proxy for the importance of laboratory results on decision making, finding 35 percent of healthcare encounters included at least one laboratory test order.6 However, the number varied greatly depending on where the healthcare encounter occurred, and the authors acknowledged the need to assume physicians based clinical decisions on results of all laboratory testing ordered in the study design.

Finally, a 2020 study found 73-94 percent of clinical cardiology guidelines from four international organizations recommended laboratory testing in the diagnosis or treatment of cardiovascular disease (CVD).7 With a narrow focus on cardiology guidelines for CVD, this study may not be generalized to broader healthcare decision making.

When quoting the “70 percent claim” in my professional promotion activities, I intended to demonstrate the value of medical laboratory professionals and clinical laboratory science in patient care. I had assumed to present how clinicians utilize laboratory testing in their diagnosis and treatment decisions. The difficulty in assessing how laboratory results impact decision making means we may never get a clear answer. Instead, what I found persuaded me to seek citable statistics reflecting us, the professionals performing testing. Now, when I engage in professional promotion, I opt for the following citations instead:

  • Over 350,000 people worked as “clinical laboratory technologists and technicians” in 2024, according to the Bureau of Labor Statistics.8 Note this website uses outdated terminology for medical laboratory professionals. This number jumps to 490,000 when including people employed as phlebotomists.9
  • Approximately 13 billion laboratory tests are performed annually in the United States according to the February 6, 2014, Federal Register.10
  • There are around 320,000 sites registered with CLIA to perform laboratory testing in the United States as of March 2024, according to the Centers for Medicare & Medicaid Services, Division of Clinical Laboratory Improvement and Qualitiy.11

Although these statistics shift the focus away from the impact of laboratory results on clinical decisions made by others, I see this as a positive change. Instead, we, the medical laboratory professionals, take center stage by quantifying our number, the volume of tests we perform, and the number of locations where we perform them. As medical laboratory professionals, we contribute to evidence-based and data driven care and, as such, I urge all of us to cite accurate and verifiable data better representing the profession in our advocacy and outreach activities.

References
  1. Centers for Disease Control and Prevention. Medical Laboratory Professionals Week. 2026. Accessed May 27, 2026. https://www.cdc.gov/lab-week/about-archive.html
  2. World Health Organization. Strengthening diagnostic capacity. Accessed May 27, 2026. https://www.who.int/activities/strengthening-diagnostics-capacity
  3. Forsman RW. Why is the laboratory an afterthought for managed care organizations. Clin Chem. 1996;42(5):813-816.
  4. Hallworth MJ. The “70% claim”: What is the evidence base? Ann Clin Biochem. 2011;48(6):487-488. doi:10.1258/acb.2011.011177
  5. Rohr UP, Binder C, Dieterle T, et al. The value of in vitro diagnostic testing in medical practice: A status report. PLoS One. 2016;11(3). doi:10.1371/journal.pone.0149856
  6. Ngo A, Gandhi P, Greg Miller W. Frequency that Laboratory Tests Influence Medical Decisions. Journal of Applied Laboratory Medicine. 2017;1(4):410-414. doi:10.1373/jalm.2016.021634
  7. Hicks AJ, Carwardine ZL, Hallworth MJ, Kilpatrick ES. Using clinical guidelines to assess the potential value of laboratory medicine in clinical decision-making. Biochem Med (Zagreb). 2021;31(1):1-11. doi:10.11613/BM.2021.010703
  8. U.S. Bureau of Labor Statistics. Occupational Outlook Handbook: Clinical Laboratory Technologists and Technicians. August 28, 2024. Accessed May 25, 2026. https://www.bls.gov/ooh/healthcare/clinical-laboratory-technologists-and-technicians.htm
  9. U.S. Bureau of Labor Statistics. Occupational Outlook Handbook: Phlebotomists. 2024. Accessed May 27, 2026. U.S. Bureau of Labor Statistics. (2025, August 28). Occupational Outlook Handbook: Clinical Laboratory Technologists and Technicians. https://www.bls.gov/ooh/healthcare/phlebotomists.htm
  10. Centers for Medicare & Medicaid Services. Federal Register Vol 79 No 25. 2014. Accessed May 25, 2026. https://www.govinfo.gov/content/pkg/FR-2014-02-06/pdf/2014-02280.pdf
  11. Centers for Medicare & Medicaid Services. CLIA Statistics. 2024. Accessed May 27, 2026. https://www.cms.gov/regulations-and-guidance/legislation/clia/downloads/statupda.pdf

Tracey K. Gardner is Program Director and Instructor at Clover Park Technical College in Lakewood, Washington.