The "optimization" lab panel: what happens when you test for everything

The logic of "measure first, intervene later" seems flawless and is therefore rarely questioned. However, it has been tested—as an intervention, with randomization and outcome tracking. The result was not what this logic predicts.

Two hundred fifty thousand people in randomized trials

The Cochrane review included 17 trials of general health checks in adults, 15 of which had outcome data — 251,891 participants. The authors assessed the risk of bias for the primary outcomes as generally low.

Result: general health checks have little to no effect on all-cause mortality (risk ratio 1.00 with a 95% confidence interval of 0.97–1.03; 11 trials, 233,298 participants, 21,535 deaths, high certainty of evidence) and on cancer mortality (1.01; 0.92–1.12). The conclusion for cardiovascular mortality is similar with slightly less certainty. Authors' conclusion: general health checks are unlikely to be beneficial. Review in Cochrane Database of Systematic Reviews.

This refers specifically to screening in people without complaints. Examination for a symptom is a different situation with a different evidence base.

Where do 'deviations' in healthy people come from

The reference interval for most indicators is constructed so that 95% of values from healthy people fall within it. It follows from the definition: for 5% of healthy individuals, the result will be outside the boundary — not because something is wrong with them, but because that is how the boundary is set.

Then arithmetic comes into play. If a panel includes 30 independent indicators, the probability that at least one will fall outside the reference range approaches four-fifths. For a panel of 60 indicators — it's even higher. This is not a property of human health, but a property of the method of defining the norm itself.

Each such deviation triggers a chain: retesting, clarifying analysis, imaging, consultation. This chain has its own risks — from procedural ones to anxiety — and these are realized in a person who initially had no issues.

Where screening is justified and where it is not

The difference between a 'useful test' and an 'just in case test' lies in whether there is proven benefit from early intervention in the asymptomatic stage. Where it is indicated, screening is included in recommendations: blood pressure, glucose, and lipids in certain age groups, and specific oncological programs.

Where the benefit is not shown, the answer is often direct. The U.S. Preventive Services Task Force concluded that there is insufficient evidence of benefit or harm from screening for vitamin D deficiency in asymptomatic adults — commentary in Annals of Internal Medicine; a separate analysis of what this means for practice was published in JAMA. What is known about vitamin D itself is in the article about vitamin D.

What exactly is sold under the 'biohacker panel'

Usually a set of three layers. The first — standard indicators that are indeed prescribed based on indications. The second — indicators whose interpretation in an asymptomatic person is not defined: a broad hormonal profile, a dozen vitamins and trace elements, inflammatory markers. The third — tests with no established clinical value at all.

The problem is not that the second and third layers are harmful in themselves, but that they come with a ready-made interpretation — usually towards a deficiency, which is then addressed by a purchase. More about how this category of products is structured can be found in the article about dietary supplements, vitamins, and medications.

Separately about 'optimal ranges'

A common tactic: a result within the reference range is declared 'not optimal' because it falls in the lower or upper third. Optimal ranges presented in this way have no source — they are not derived from studies that compared outcomes in people within different parts of the norm.

Narrowing the norm is the easiest way to turn a healthy person into a client. The same tactic in other categories is discussed in the articles about DNA tests and about microbiome tests.

Analysis answers a posed question

Tests answer a posed question. Without a question, they return a set of numbers, some of which, by design, will fall outside the reference range, and then the person deals not with their health, but with the consequences of the measurement. Decisions about which examinations are needed in a specific situation are made with a doctor.

Count it from a photo

Frequently asked questions

Is it useful to regularly 'get everything tested'?

A Cochrane review of 17 trials with 251,891 participants found no effect of general health checks on all-cause mortality (risk ratio 1.00) and cancer mortality (1.01). Authors' conclusion: general health checks are unlikely to be beneficial. This refers to people without complaints.

Why are some indicators outside the normal range for a healthy person?

The reference interval is constructed so that 95% of values from healthy people fall within it. This means that for 5% of healthy individuals, the result will fall outside these bounds. With a panel of thirty indicators, the probability of at least one deviation approaches four-fifths.

Should I check my vitamin D level if I have no symptoms?

The U.S. Preventive Services Task Force concluded that there is insufficient evidence to assess the benefits and harms of screening for vitamin D deficiency in asymptomatic adults.

What is an "optimal range" within the normal limit?

A practice where a result within the reference range is declared not good enough due to its position in the lower or upper part of the interval. There are usually no studies comparing outcomes for people within different parts of the normal range to support such ranges.

So, are tests not needed at all?

We are talking about screening without complaints or specific questions. A test ordered to verify a specific hypothesis and a panel done "just in case" are different things with different evidence bases.

Read next

• Vitamin D: how much you need, where to get it, and when to get tested — Vitamin D differs from other vitamins in that humans can produce it themselves—in the skin under ultraviolet light.
• DNA test "tailored to your genome": what is known about nutrition based on genes — The promise sounds convincing: a saliva sample, two weeks of waiting, and a diet tailored to your heredity.
• Microbiome tests: why two samples give different answers — An at-home microbiome test looks like a standard lab analysis: a test tube, a laboratory, and a report with percentages and a list of foods.

This article is for general information. It is not medical advice, a diagnosis, or a prescription for treatment or a diet, and it does not replace a consultation with your doctor. If you have a health condition, are pregnant, take medication, or follow a diet prescribed to you, decisions about food belong with your doctor.

Figures from regulations, guidelines and studies are given as they stood when this article was prepared and may since have changed; check them against the primary sources. This article is not advertising, an offer, or individual advice, and neither the author nor the site owner is responsible for decisions taken on the basis of it.