health and wellness

What parents need to know about Tylenol, autism and the difference between finding a link and finding a cause in scientific research

The article discusses the ongoing debate regarding the potential link between prenatal acetaminophen (Tylenol) use and autism. While some studies show weak associations, establishing causation remains challenging. Factors like dosage response and sibling outcome comparisons are critical for understanding this complex issue, highlighting the need for more thorough research and consulting healthcare professionals.

Published

10 months ago

September 26, 2025

The Conversation

file 20250925 56 j47ciu.jpg?ixlib=rb 4.1 — In cases where associations are found, researchers must consider dosage response, differences between siblings and other factors to determine a cause-and-effect relationship. Ronaldo Schemidt/AFP via Getty Images

What parents need to know about Tylenol, autism and the difference between finding a link and finding a cause in scientific research

Mark Louie Ramos, Penn State

Claims from the Trump White House about links between use of the painkiller acetaminophen – often sold under the brand name Tylenol in the U.S. – during pregnancy and development of autism have set off a deluge of responses across the medical, scientific and public health communities.

As a father of a child with level 2 autism – meaning autism that requires substantial support – and a statistician who works with such tools as those used in the association studies cited by the White House, I find it useful to think about the nuances of association versus causation in observational studies. I hope that this explanation is helpful to parents and expecting parents who, like me, are deeply invested in the well-being of their children.

a bunch of white pills are shown with the words tylenol 500 on them in red — The painkiller acetominophen is often sold under the brand name Tylenol in the U.S. AP Photo/Jae C. Hong

Association is not causation, but …

Most people have heard this before, but it bears repeating: Association does not imply causation.

An often-cited example is that there is a very strong association between ice cream sales and incidents of shark attacks. Of course, it goes without saying that shark attacks aren’t caused by ice cream sales. Rather, in the summertime, hot weather drives more appetite for ice cream and beach time. The increased number of people at the beach does, in turn, cause the likelihood of shark attacks to increase.

Yet pointing this out on its own is neither intellectually satisfying nor emotionally appeasing when it comes to real-life medical concerns, since an association does suggest potential for a causal relationship.

In other words, some associations do end up being convincingly causal. In fact, some of the most consequential discoveries of the past century in public health, like the links between smoking and lung cancer or the human papillomavirus (HPV) and cervical cancer, started out as findings of very strong association.

So when it comes to the issue of prenatal acetaminophen use and autism development, it is important to consider how strong the association found is, as well as the extent to which such an association could be considered causal.

Establishing causal association

So how do scientists determine if an observed association is actually causal?

The gold standard for doing so is conducting what are called randomized, controlled experiments. In these studies, participants are randomly assigned to receive treatment or not, and the environment where they are observed is controlled so that the only external element that differs among participants is whether they received treatment or not.

In doing this, researchers reasonably ensure that any difference in the outcomes of the participants can be directly attributed as being caused by whether they received the treatment. That is, any association between treatment and outcome can be considered causal.

Yet oftentimes, conducting such an experiment is impossible, unethical or both. For instance, it would be highly difficult to gather a cohort of pregnant women for an experiment and extremely unethical to randomly assign half of them to take acetaminophen, or any other medication for no particular reason, and the other half not to.

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So when experiments are simply infeasible, an alternative is to make some reasonable assumptions on how observational data would behave if the association was causal and then see if the data aligns with these causal assumptions. This can very broadly be referred to as observational causal inference.

Parsing what the studies mean

So how does this apply to the current controversy over the potential for acetaminophen use during pregnancy to affect the fetus in a way that could result in a condition like autism?

Researchers who try to understand causal roles and links between one variable and potential health outcomes do so by considering: 1) the size and consistency of the association across multiple attempts to estimate it, and 2) the extent to which such association has been established under observational causal inference frameworks.

As early as 1987, researchers have been working to measure possible associations between acetaminophen use during pregnancy and autism. A number of these studies, including multiple large systematic reviews, have found evidence of such associations.

For instance, a 2025 review of 46 studies that examined association between acetaminophen use and an array of neurodevelopmental disorders, including autism, identified papers with five positive associations between acetaminophen and autism.

In one of those studies, which examined 73,881 births, the researchers found that children who were exposed to acetaminophen prenatally were 20% more likely to develop borderline or clinical autism spectrum conditions. Another examined 2.48 million births and reported an estimated association of only 5%.

Both of those are weak associations. For context, estimations of increased lung cancer risk from smoking in the 1950s were between 900% to 1,900%. That is, a smoker is 10 to 20 times more likely than a nonsmoker to develop lung cancer. By comparison, in the two autism studies above, a pregnant woman who takes acetaminophen is 1.05 to 1.20 times more likely than one who does not take the drug to have a child who would be later diagnosed with autism.

It’s also important to keep in mind that many factors can affect how well a study is able to estimate an association. In general, larger sample sizes provide both greater power to detect an association if one does exist, as well as improved precision over estimating the value of the association. This does not mean that studies with smaller sample sizes are not valid, only that from a statistical perspective, researchers like me place greater confidence in an association drawn from a larger sample size.

Once an association – even a small one – is established, researchers then must consider the extent to which causation can be claimed. One way to do this is through what’s called dose-response. This means looking at whether the association is higher among women who took higher doses of acetaminophen during pregnancy.

The study mentioned above that looked at 2.48 million births shows an example of dose-response. It found that pregnant women who reported taking higher doses have higher autism risk.

Another way to examine possible causality in this context is to analyze sibling outcomes, which that same paper did. Researchers looked at whether associations between acetaminophen and autism persisted within families with more than one child.

For example, in a family with two children, if the mother used acetaminophen during one pregnancy and that child was later diagnosed with autism, but she did not use it during the other pregnancy and that child was not diagnosed, then this strengthens the causal claim. Conversely, if acetaminophen was used during the pregnancy of the child who was not diagnosed with autism and not used during the pregnancy of the child who was, then that weakens the causal claim. When this was included in the analysis, the dose-response disappeared, and in fact the overall 5% increased risk mentioned before likewise disappeared. This weakens the claim of a causal relationship.

Consult your doctor

At present, there is clearly not enough evidence to establish a causal association between prenatal acetaminophen use and autism.

Yet as a parent who wonders if my daughter will ever be able to write her name, or hold a job or raise kids of her own, I understand that such explanations may not appease the fears or concerns of an expecting mother who is suffering from a fever.

Naturally, all of us want absolute certainty.

But that’s not possible when it comes to acetaminophen use, at least not at this time.

Your doctor will be able to provide you with much sounder advice than any existing study on this topic. Your OB-GYNs are very likely aware of these studies and have much better judgment as to how these results should be considered in the context of your personal medical history and needs.

Researchers, meanwhile, will continue to dig deeper into the science of this critically important issue and, hopefully, provide greater clarity in the years to come.

Mark Louie Ramos, Assistant Research Professor of Health Policy and Administration, Penn State

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Health

Research Reveals Persistent Racial Disparities in Stroke Treatment and Outcomes

Published

1 day ago

August 3, 2026

Daily News Staff

woman comforting another woman. Stroke treatment. — Photo by RDNE Stock project on Pexels.com

Three new studies shared this week at the Society of NeuroInterventional Surgery (SNIS) 23rd Annual Meeting deliver a clear message: stroke care in the U.S. is improving, but those gains are not reaching everyone equally. Researchers found persistent disparities tied to race, geography, and socioeconomic status—factors that can shape whether a patient receives advanced treatment, how quickly they reach specialized care, and ultimately, whether they survive.

Stroke remains one of the nation’s leading causes of death and long-term disability. In recent years, breakthroughs in emergency response systems and minimally invasive procedures have expanded what’s possible in the critical first hours after a stroke. But the latest findings suggest that access to those life-saving advances still depends too heavily on who you are and where you live.

Study 1: Treatment gaps widen as strokes get more severe

The first study, “Racial Disparities in Endovascular Thrombectomy Widen with Stroke Severity: A National Inpatient Sample Analysis,” examined more than 325,000 acute ischemic stroke patients treated at U.S. teaching hospitals between 2018 and 2022.

The focus was endovascular thrombectomy (EVT), a minimally invasive procedure in which specialists remove a clot from a blocked artery in the brain. EVT can be a game-changer for eligible patients—but researchers found Black patients were less likely than white patients to receive it across all levels of stroke severity.

What stood out most: the disparity grew as stroke severity increased. At a National Institutes of Health Stroke Scale (NIHSS) score of 20, the predicted probability of receiving EVT was:

33% for white men
32% for white women
28% for Black men
26% for Black women

Co-first author Muhammed Amir Essibayi, MD, MSc, FRCP, noted that timely access becomes even more critical as severity rises—yet the treatment gap becomes more pronounced. The study also highlighted an intersectional pattern, with Black women consistently least likely to receive EVT.

Study 2: Hemorrhagic stroke deaths are falling—but disparities persist

The second study, “Reducing Inequalities in Stroke Events-Hemorrhagic Disparities (RISE-HD): A 10-year Statewide Analysis of Social Determinants of Mortality in Hemorrhagic Stroke,” analyzed more than 120,000 patients hospitalized with hemorrhagic stroke in Florida between 2013 and 2024.

There was good news: mortality rates declined significantly over the decade, suggesting real progress in stroke systems and hospital care.

But after adjusting for age, sex, and comorbidities, disparities remained. Black patients had higher odds of in-hospital mortality than white patients. Higher mortality was also associated with:

Living in rural areas
Having Medicaid or other non-commercial insurance

Researchers also found regional differences across Florida, pointing to uneven access to specialized stroke care.

Primary author Natália Vasconcellos, MD, MSc, emphasized that improving outcomes for everyone will require addressing barriers to specialized stroke systems—especially in underserved communities.

Study 3: The “Stroke Belt” has two different access problems

The third study, “Dual Pathways to Hemorrhagic Stroke Mortality Across the U.S. Stroke Belt: Rural Neurointerventional Isolation and Urban Structural Vulnerability,” looked at hemorrhagic stroke mortality across 433 counties in the “Stroke Belt,” a region long associated with higher stroke rates and worse outcomes.

Researchers compared factors linked to mortality in rural versus urban counties, including:

Distance to the nearest Comprehensive Stroke Center
Community-level socioeconomic disadvantage
Racial and economic segregation
HIV burden

They found the drivers of mortality differed sharply by setting:

In rural counties, longer travel times to Comprehensive Stroke Centers were more strongly associated with higher mortality.
In urban counties, racialized economic segregation and HIV burden were more strongly associated with poorer outcomes—even when specialized care was geographically closer.

Dylan Yates, a medical student at Tulane University School of Medicine, summarized the takeaway: the neurointerventional access gap in the Stroke Belt is “not one problem, it is two.” Solutions need to match the reality on the ground—strengthening transfer networks and specialty connections in rural areas, while addressing structural disadvantage and underinvestment in urban communities.

What to watch for: where the system can improve

Across all three studies, the common thread is that medical innovation alone doesn’t guarantee equitable outcomes. Researchers pointed toward targeted interventions that could help close the gap, including:

More consistent, equitable treatment pathways for advanced stroke procedures like EVT
Stronger stroke transfer networks to reduce delays—especially in rural regions
Expanded access to specialty stroke care and Comprehensive Stroke Centers
Community-level investment and structural reforms in underserved urban neighborhoods

For patients and families, these findings also reinforce the importance of recognizing stroke symptoms quickly and calling 911 immediately. Time is brain—yet the system must ensure that “time” and “access” don’t vary based on race, ZIP code, or insurance status.Source: Society of NeuroInterventional Surgery (SNIS), July

If You’re Feeling Stressed by Pricey Meds, Pharmacists Can Help

Stressed by Pricey Meds? If your wallet is feeling the squeeze of prescription drug costs as other living expenses like grocery and energy prices rise, you’re not alone. That’s where a powerful ally can help you manage drug costs: a health-system pharmacist.

Published

4 days ago

July 31, 2026

Daily News Staff

If You’re Feeling Stressed by Pricey Meds, Pharmacists Can Help

(Feature Impact) If your wallet is feeling the squeeze of prescription drug costs as other living expenses like grocery and energy prices rise, you’re not alone.

More people are worrying about affording essential medications these days. In fact, more than 40% of adults said they skipped doses or didn’t fill prescriptions in the past year due to cost, according to a KFF Health survey.

People who take multiple drugs to manage chronic conditions often feel this pinch even more severely. They’re also more likely to make more frequent visits to their clinic or health system for care. That’s where a powerful ally can help them manage their drug costs: a health-system pharmacist.

These medication experts work side-by-side with the clinicians who prescribe drugs in health care practices – and sometimes prescribe medications themselves. Their deep knowledge can help people get the most out of the drugs they take.

“Pharmacists really know the full picture of medications, including pricing, insurance coverage, alternative therapies and potential side effects,” said Lindsey Amerine, PharmD, chief pharmacy officer for the Cleveland Clinic. “That’s why it’s helpful to not only count on your doctor to diagnose your condition and prescribe therapies, but also your pharmacist to optimize your medications.”

Get a Comprehensive Review of Your Medications

Asking the pharmacist on your health-system care team to go over your medications may reveal opportunities to save, Amerine said. Health-system pharmacists are uniquely qualified to provide this service because they keep close track of medication costs as well as approvals of new drugs and how those compare to older options.

A full review might reveal:

Drugs once needed may not be as useful anymore. People often continue taking medications unaware that something new could offer greater benefits or their condition no longer requires the same therapy.
Changes in your condition may mean you could safely take a lower dosage of a drug, thereby reducing costs.
There may be less costly alternatives that would work as well such as a generic or older medication.

Get Help Exploring Discount Options

You’ve probably heard about programs that can help lower prescription costs, including discount and patient assistance programs. Pharmacists can help you understand how to navigate these programs and access potential discount programs and opportunities, Amerine said. Here’s how:

Pharmacists can guide you through discount programs your health system offers.
They can check your eligibility for drug maker discounts and help you understand how those discounts work with your insurance, especially if you have a high-deductible plan.
Pharmacists can help you navigate the various prescription cost-savings programs and how they work.
They can also help you learn about patient assistance programs that provide free or discounted medications to people who cannot afford them.

Medications are a vital part of your health care. Before you try to stretch a costly medicine or give it up altogether, talk to the medication expert on your health care team: your health-system pharmacist. For more information, visit yourpharmacist.org.

Why It Pays to Talk Meds with a Pharmacist

“My doctor prescribed it, so I must need it.” Often this is true, but not always. People sometimes take drugs longer than they need to, at doses higher than necessary or that may interact with other medications.

Just as you’d see a heart specialist about an odd pulse rate, it can help to see a pharmacist – your medication specialist – to discuss your prescriptions.

Of all health care professionals, pharmacists have the deepest knowledge of drug interactions and safety issues. They’re experts on how the effectiveness of different medications – brand name and generic – compare. They also closely track changes in prices and know when a drug’s cost has dropped or if an effective, less costly alternative is available.

Health-system pharmacists’ expertise is especially helpful for those with multiple chronic conditions who typically take several medications with more benefits, costs and side effects to balance.

Talking with a pharmacist can ensure your prescriptions are best for you and that you have access to the most affordable options. collect?v=1&tid=UA 482330 7&cid=1955551e 1975 5e52 0cdb 8516071094cd&sc=start&t=pageview&dl=http%3A%2F%2Ftrack.familyfeatures track

SOURCE:

American Society of Health-System Pharmacists

Daily News Staff