A statistic frequently used to demonstrate the importance of clinical laboratory testing may not have the evidence behind it that many laboratory professionals assume.
In an article published by the American Society for Clinical Laboratory Science (ASCLS), Tracey K. Gardner, MSEd, MLS(ASCP)CM, examines the longstanding claim that 70% of medical decisions are based on laboratory results—and explains why she no longer uses the statistic in laboratory advocacy and recruitment efforts.
Gardner traced the claim to a 1996 article by Rodney W. Forsman, who wrote that laboratory testing influences 60% to 70% of critical medical decision-making, including admission, discharge, and drug therapy. However, Forsman did not provide direct evidence supporting that percentage. According to Gardner, the figure instead relied on personal communications and observations from colleagues.
One of Dark Daily’s editors posted an informal poll on LinkedIn asking about people’s views on the 70% statistic. Here are the results shortly before the poll closed on Aug. 20:
- 35% said the stat is overly co-opted by laboratories.
- 29% said the stat is legitimate or close enough.
- 24% said the stat is too old or vague.
- 12% said the stat helps demonstrate the lab’s value.
Seventeen people responded to the poll, so at best the results can be called a snapshot of industry opinions. But clearly there are varying views about the 70% figure.
Research produces different estimates
Subsequent research has attempted to quantify the laboratory’s role in clinical decision-making, but the results vary substantially depending on methodology.
A 2016 study of cardiology and oncology physicians in the US and Germany estimated that 66% of medical decisions were based on laboratory testing, but the finding relied on physicians’ perceptions. A 2017 study found that 35% of healthcare encounters included at least one laboratory test order. Meanwhile, research examining cardiovascular disease guidelines found laboratory testing was recommended in 73% to 94% of clinical guidelines studied.
Gardner argues that the difficulty of defining and measuring how laboratory results influence clinical decisions means the profession may never arrive at a single defensible percentage.
Instead, she recommends that medical laboratory professionals emphasize statistics that can be independently verified. More than 350,000 people worked as clinical laboratory technologists and technicians in 2024, according to federal labor data, rising to about 490,000 when phlebotomists are included. Other government data cited by Gardner indicate approximately 13 billion laboratory tests are performed annually in the US and roughly 320,000 sites were registered to perform testing under CLIA as of March 2024.
For clinical laboratory professionals, Gardner’s argument offers a different approach to demonstrating the laboratory’s value: focus advocacy on measurable workforce, testing volume, and laboratory infrastructure rather than repeating a compelling statistic whose evidence base remains uncertain.
This article was created with the assistance of Generative AI and has undergone editorial review before publishing.
