Epidemiologists and public health experts spent the past weekend collectively shaking their heads at the latest harmful pronouncement from Florida’s provocative surgeon general, Joseph Ladapo, who on Friday announced that he was recommending against mRNA-based COVID-19 vaccines for men ages 18 to 39.

Ladapo based his recommendation on a dubious analysis, which was posted online by the Florida Department of Health. According to a misleading press release from the department, the analysis found “an 84% increase in the relative incidence of cardiac-related death among males 18-39 years old within 28 days following mRNA vaccination.”

The press release says the analysis was carried out by the department, but it was posted as a simple PDF without the health department’s official letterhead, and—most strikingly—no authors are listed, which is highly unusual. It has clearly not been peer-reviewed, published in a scientific journal, or even thoroughly edited.

“Studying the safety and efficacy of any medications, including vaccines, is an important component of public health,” Ladapo said in the press release. “Far less attention has been paid to safety and the concerns of many individuals have been dismissed—these are important findings that should be communicated to Floridians.”

Experts roundly dubbed the analysis “utter rubbish,” “extremely misleading,” and “comically bad.” Some called the analysis method “terrible,” and one epidemiologist called it “the absolute most batshit study design & analysis plan I have ever seen.” Others noted that the conclusion “smells of p-hacking” and data cherry-picking.

These reactions are likely unsurprising to anyone who has followed Ladapo’s work as Florida’s top doctor. Brought in by Governor Ron DeSantis in 2021, Ladapo has spent the pandemic downplaying the threat of COVID-19, fighting public health measures, surrounding himself with prominent anti-vaccine voices, and attacking life-saving COVID-19 vaccines.

But fearmongering and discouraging use of COVID-19 vaccines amid the national fall booster campaign and ahead of an anticipated winter wave has the potential to do further harm to public and individual health. The US booster rates are already abysmal. Less than half of people who received a primary series have gotten a single booster. Only about 38 percent of people age 50 and older, who are more vulnerable to severe disease, have gotten a second booster. And so far, only 11.5 million Americans—roughly 3.5 percent of the population—have gotten the updated bivalent booster during this fall campaign, according to the latest figures from the Centers for Disease Control and Prevention.

COVID-19 vaccines and boosters have proven remarkably safe and highly effective at preventing severe disease and death. But, that hasn’t stopped some right-wing politicians and like-minded anti-vaccine voices and COVID-19 downplayers, such as Ladapo, from attacking them. This new “analysis” is a prime example.

As the reactions from experts suggest, there are a lot of things wrong with the analysis—too much to delve into in a single story. But, below are some of the highlights of just how bad this analysis really is.

The “batshit” study design

The analysis uses an unusual “alternative” epidemiological study design called a self-controlled case series (SCCS). This is a study design that was initially developed to assess vaccine safety, though not necessarily vaccine-related deaths, as was used for Ladapo’s analysis. The study design is legitimate—in that it is an established method that has been used before for similar purposes. But, as experts have pointed out, that doesn’t make it the best design, or even a good one.

To assess a vaccine’s safety and effectiveness, you might expect a study to compare a group of vaccinated people to a similar group of people who were not vaccinated, or perhaps received a placebo. Then you could compare the outcomes of people in the two groups, possibly attributing differences—the number of infections or possible side effects—to the obvious variable: the vaccine. But in a case-series design, there is no control or comparator group. The design uses each individual as their own comparator in fixed windows of time, comparing a risk period to a later control period.

By design, the study must only include people who experience both a specific intervention—such as a vaccination—and a specific health event after the intervention—such as a possible vaccine side effect. The study then looks at the timing of the health event in relation to the intervention, assessing if people appear more likely to experience the event in the risk period soon after the intervention compared with a later control period. If so, it suggests that the intervention played a role in the event.

For example, a 2004 study published in the New England Journal of Medicine used a case-series design to see if people are more likely to have a stroke or heart attack after routine vaccination or an acute infection. The study concluded that acute infections did transiently increase risk of stroke and heart attack, while vaccination did not.

https://arstechnica.com/?p=1889104