Numerous studies over the past 30 years have convincingly demonstrated that 30% of laboratory tests are unnecessary. A series of articles posted in this blog between September 2 and December 22, 2013, discussed the problems that arise from ordering too many laboratory tests. Unnecessary laboratory testing has the potential to cause both indirect and direct harm to patients. The more tests that are ordered, the greater the likelihood that a result will fall outside of the normal range. Reference ranges are usually set so that 95% of the healthy population falls within the reference range. This means that 5% of healthy individuals may fall outside of this range. If 20 laboratory tests are ordered, the probability of an abnormal result is 64%.
Once a patient has an abnormal result, the test may be repeated or a confirmatory test is ordered. The patient may be referred to a specialist and imaging or an invasive procedure may be performed. Both of these have inherent risks.
A procedure may be unnecessarily postponed while this insignificant result is being pursued. The physician’s attention may be diverted from the primary problem leading to a diagnostic error. Patients may even develop iatrogenic anemia from repeat blood draws. This chain of events increases cost, worry, discomfort and risk.
The blog posted on October 20, 2013 specifically addressed the problems associated with health screening. Health screening is often promoted in the belief that it is always better to prevent or detect a disease early than to treat it later.
More recent research has discovered that health screening often finds insignificant abnormalities, called incidentalomas, that subsequently lead to over-diagnosis, overtreatment and possibly harm. In spite of this new data, patients usually opt for health screening because they tend to overestimate the risk reduction associated with screening and underestimate risk of intervention (Ann Fam Med 2012; 10:495-502).
Screening really promotes disease, not health. Today, the fastest way to get heart disease, autism, glaucoma, diabetes, vascular problems, osteoporosis and cancer is to be screened for it.
Aaron Carroll writes the Incidental Economist blog. On May 4, 2015, he elegantly explained the problems associated with health screening in his video, entitled,
Healthcare Triage: Frequent Lab Testing Isn’t Very Useful theincidentaleconomist.com/wordpress/heal…
I strongly recommend that readers of ClinLabNavigator take the time to watch this powerful video. I leave you with my favorite quote from Dr. Carroll, “Ordering a lab test is like picking your nose in public. If you find something, you better know what you are going to do with it.”
You can follow Aaron Carroll on Twitter at @aaroncarroll and read his blog at theincidentaleconomist.com.