Fact-check: NEJM's two-minute summary of the SELECT trial

What the video covers

NEJM's video abstract for the SELECT trial: an international, double-blind, placebo-controlled trial of semaglutide 2.4 mg weekly in adults aged 45 or older with established cardiovascular disease and a BMI of 27 or more but no diabetes. The narration gives the enrolment, the follow-up, the primary composite result, the direction of the secondary endpoints and the discontinuation finding, and sends viewers to the full paper.

What it gets right

Everything stated is in the paper (PubMed 37952131). 17,604 participants were randomised. Mean follow-up was 39.8 months. The primary endpoint, a composite of death from cardiovascular causes, non-fatal myocardial infarction or non-fatal stroke, occurred in 6.5 percent of the semaglutide group and 8.0 percent of the placebo group. Cardiovascular death alone was not significantly different but favoured semaglutide; the heart-failure composite and all-cause death were not formally tested for superiority under the hierarchical plan but also favoured semaglutide. More participants stopped semaglutide than placebo because of adverse events, largely gastrointestinal. The video's conclusion is the paper's conclusion.

The population framing is precise and important: this is secondary prevention in people who already had cardiovascular disease, not a general population of people with obesity.

What it leaves out or overstates

Nothing is overstated. What a two-minute abstract cannot hold is the arithmetic a reader needs. The hazard ratio was 0.80 (95 percent confidence interval 0.72 to 0.90), a 20 percent relative reduction. The absolute difference was 1.5 percentage points over about 40 months, which works out to roughly 67 people treated for that period per primary event avoided. Discontinuation for adverse events was 16.6 percent with semaglutide against 8.2 percent with placebo. Mean weight change was about minus 9.4 percent against minus 0.9 percent, and the paper notes that the separation of the event curves began early, before most of the weight loss, which is why the mechanism is discussed as at least partly independent of weight.

The video also cannot tell you who the result applies to. SELECT excluded people with diabetes and enrolled people with prior heart attack, stroke or peripheral arterial disease; it does not show that semaglutide prevents a first cardiovascular event in someone without established disease. In March 2024 the FDA added the SELECT indication to the Wegovy label, worded as reducing the risk of major adverse cardiovascular events in adults with established cardiovascular disease and either obesity or overweight.

Where to go next

The Cleveland Clinic clip next in this playlist is from a SELECT investigator. FormBlends Research digests SELECT alongside SUSTAIN-6, FLOW and the tirzepatide outcome trials, and FormBlends Science explains the candidate mechanisms. If you are weighing cost, the GLP-1 cost report at formblends.com lays out brand and compounded pricing. Compounded semaglutide, which FormBlends dispenses, is not FDA approved and carries no cardiovascular indication; SELECT studied Wegovy pens.