Is a Korean comprehensive health checkup worth having?

Asked in English, this question is answered almost entirely by the companies selling the checkups. Their answer is that Korean screening is thorough, uses excellent equipment, and costs a fraction of the American price. All three are true. None of them is an answer to whether the tests find anything worth finding.

The evidence does answer it, and the answer is neither yes nor no. It is that a comprehensive checkup is not a test at all. It is a bundle of tests sold as one product, and the bundle is not uniform.

Checkups as a whole have not lowered mortality#

This has been tested directly. A Cochrane review pooled randomised trials that offered adults a general health check — screening for more than one disease across more than one organ system, in people not selected for being at risk — against no health check.

Cancer mortality was 1.01 (0.92 to 1.12) and cardiovascular mortality 1.05 (0.94 to 1.16). The review's stated conclusion is that general health checks are unlikely to be beneficial. That is an unusually flat result for a question this large, and it is the finding the packages are sold against.

Inside Korea's own programme, one test works and another does not#

The Korean National Cancer Screening Program has offered gastric cancer screening to everyone aged 40 and over since 1999, by either upper endoscopy or an upper gastrointestinal series. A nested case-control study drew on a cancer-free cohort of 16,584,283 people, comparing 54,418 who died of gastric cancer against 217,672 matched controls.

Two tests, one programme, one population, one outcome. Endoscopy roughly halves the odds of dying of gastric cancer, and does more the more often it is repeated, which is the dose-response pattern expected of something that genuinely works. The barium series does nothing measurable at all.

This is the strongest argument for Korean screening that exists, and it is a specific one. It is an argument for endoscopy in a country with high gastric cancer incidence. It is not an argument for the package that endoscopy arrives in.

And one test in the bundle causes net harm#

Thyroid ultrasound is routinely added to Korean checkups, often for a small extra fee. Korean thyroid cancer incidence rose 6.4-fold between 1999 and 2008, with 94.4 percent of the increase being tumours under 20 mm. Mortality did not move. A 63-country analysis estimated that over 85 percent of thyroid cancer cases in Korean women were attributable to overdiagnosis, the highest share in the world.

Overdiagnosis is not a near miss. It means people who would never have become ill were given a cancer diagnosis, and many of them a thyroidectomy, its complication risk, and lifelong medication. What that surgery costs is covered separately by this publication.

What the premium package is actually selling#

A radiologist reviewed the 190 comprehensive examination programmes advertised by ten university hospitals in Seoul. Of those, 132 — 69.5 percent — included CT, averaging 1.4 scans, and only the basic studies in each programme were counted.

The upgrade being paid for is largely more imaging, and more imaging is more radiation. That is not a hidden cost so much as an unstated one: the premium tier's distinguishing feature is the thing a person would want less of, all else being equal.

The cost that does not appear on the invoice#

Scanning a well person finds things. A German population cohort gave whole-body MRI to 3,371 of its 6,753 participants and disclosed what it found. Biopsies across the cohort rose from 6.9 to 9.9 per 100 observation-years.

• Non-malignant biopsy results rose by a rate ratio of 1.39 (1.22 to 1.58) among people who had findings disclosed, against 1.09 (0.85 to 1.38) among those who did not.
• Malignant results also rose, by 1.74 (1.27 to 2.42), on a far smaller base.
• The authors concluded that most biopsies found nothing and few cancers were diagnosed, indicating overtesting and overdiagnosis.

The checkup's price is what the checkup costs. The biopsies, the repeat scans, the follow-up appointments and the months of not knowing are paid separately, by whoever the scan happened to alarm.

Why Korea scans as much as it does#

An experimental vignette survey of 1,229 Koreans asked whether they would want an MRI for uncomplicated headache or non-specific low back pain, situations in which imaging is not indicated. Before any reduction in out-of-pocket cost, between 30 and 50 percent said yes, depending on income and complaint. After a reduction, 78 to 98 percent did, across every income quintile.

Demand for scanning in Korea tracks price rather than indication. That is not a criticism of patients; it is what happens when a test is cheap, available, and framed as prudence. It is also why the sellers' strongest argument — that this is inexpensive — is the part of their case that should give the most pause.

What this does not say#

1. It does not say to skip screening. Korea's endoscopy result is among the strongest in cancer screening anywhere, and the national programme's targeted components are not what the Cochrane review was testing.
2. The Cochrane result concerns general health checks in adults unselected for risk. It says nothing about someone with symptoms, a family history, or an established condition.
3. The Korean endoscopy study is observational. Nested case-control designs can be affected by who chooses to be screened, and the authors adjusted for what was recorded rather than for everything that matters.
4. The radiation survey read published programme descriptions from ten Seoul hospitals in 2016 and counted only each programme's basic studies. Doses elsewhere, and today, may differ.
5. The incidental-findings cohort used whole-body MRI in Germany, which is neither the same test nor the same population as a Korean checkup. It is evidence that scanning well people triggers procedures, not a measurement of how often a Korean checkup does.
6. None of this prices the reassurance of a normal result, which is what many people are buying and which no trial has measured well.

The defensible summary is that the checkup is the wrong unit to evaluate. Ask what is in the package and what each thing in it is known to do, because the same national programme has produced one of screening's clearest successes and one of its clearest failures, and they are sold to the same person on the same morning.