Part of this is just that insurance coverage lags science. We've known that ApoB is more accurate than LDL since the 1990's or 2000's, but to be covered by insurance, several more steps have to happen.
First, the major professional societies (like the American College of Cardiology or National Lipid Associations) have to issue formal guidelines.
Then, the USPSTF (US Preventive Services Task Force) needs to review all of the evidence. They tend to do reviews only every 5 or 10 years. (Countries aside from the US have different organizations that perform a similar role.)
If the USPSTF issues an "A" or "B" rating, then insurance companies are legally obligated to cover ApoB testing. But that also introduces a year or two lag since medical policies are revised and apply to the next plan year.
The net effect is that the entire system is 17 years, on average, behind research.
