When a newspaper reporter bothers to explore the math behind dermatology’s biggest anti-tan slam, the numbers don’t add up.

“Even the IARC’s strongest study — which followed more than 100,000 women over eight years — found that less than three-tenths of one percent who tanned frequently developed melanoma, while less than two-tenths of one percent who didn’t tan developed melanoma. Almost all the other studies in the report did not establish a strong link between the two. The overall risk of contracting melanoma — whether using tanning beds or not — remains well under 1 percent. For that reason, using the 75 percent statistic is misleading, said Dr. Lisa M. Schwartz, general internist at Veterans Affairs Medical Center in VT and co-author of “Know Your Chances,” a book on understanding health statistics,” The Wilmington-News Journal reported.

Schwartz told the News Journal, “Melanoma is pretty rare and almost all the time, the way to make it look scarier is to present the relative change, the 75 percent increase, rather than to point out that it is still really rare.”

That’s not all of it though.

1. The IARC studies — once skin type I subjects are removed from the data (who cannot tan in North American tanning facilities, but sometimes do in home units or in medical devices that emit UV) — no longer show any difference between tanners and non-tanners.
2. The IARC studies included home unit data and medical device data, which made up half of the subjects in the “75 percent” stat. Home units and medical devices made up most of the risk.

Why doesn’t dermatology admit this confounding information when using the “75 percent” statistic? If they did, they’d have no case.