With only ‘shaky data’ to go on, it’s tough to practice evidence-based medicine during the Covid-19 pandemic


Part of my job as an obstetrician is to keep up with the latest evidence so I can provide the best care for my patients. But I’ve never felt as dependent as I am today on shaky data to make what could be life or death decisions.

By Neel Shah

Part of my job as an obstetrician is to keep up with the latest evidence so I can provide the best care for my patients. But I’ve never felt as dependent as I am today on shaky data to make what could be life or death decisions.

In a normal month, I receive a stack of medical journals to leaf through and actively seek out new reports online. I focus my attention on the most rigorous studies, those most likely to draw conclusions we can be confident in. These generally include a large number of patients and well-designed methods to reduce bias.

I quickly cast aside studies that include just a handful of patients or provide no formal way of accounting for context. Yet today, these kinds of studies are all I have to go on when it comes to Covid-19 and pregnancy. In just the last few days, practitioners in my field have changed their minds on critical issues based on a handful of examples and counterexamples.

I have been telling my pregnant patients for weeks that there is no evidence that the virus responsible for Covid-19 can be transmitted to their developing babies. That’s according to a small number of cases published in China. But late in March new evidence emerged, again from a small number of cases in China, that “vertical transmission” from a mother to her fetus may be possible.

The evidence is far from definitive, but it is suspicious enough to warrant further attention and scrutiny. This is one of the reasons the American Society for Reproductive Medicine has called for a temporary suspension of most fertility treatments. It also means that those trying to conceive should be extra vigilant in practicing social distancing measures to avoid infection.

In normal times, it is precisely because of our need to deal with uncertain probabilities that clinicians and scientists use careful and measured language. Saying there is “no evidence” that pregnant moms can pass the virus to their babies in utero is not the same thing as saying pregnant moms cannot pass along the virus. Similarly, saying evidence suggests “possible transmission” of the virus through the placenta is not the same thing as saying it definitely occurs. Nuanced but consequential differences like these can be extraordinarily challenging to communicate, from both sides.

These are not normal times. The speed at which knowledge is evolving is humbling. It is happening in all fields, of course, not just in obstetrics. Nearly every day the New England Journal of Medicine and other journals publish new case reports that change our understanding of the virus.

And it isn’t just new evidence that is challenging our assumptions. It is also how the context of an unprecedented pandemic is complicating our understanding of prior evidence.

For example, there is a large body of data demonstrating that continuous labor support from doulas or birth partners improves outcomes for people giving birth. But there is an equally important body of evidence that social distancing can reduce transmission in epidemics, protecting more people against infection, including the health care workers who provide both emergency care to Covid-19 patients and “regular” care to everyone else.

The largest health systems in New York City recently announced they were restricting all visitors from the hospital, including birth partners, amid skyrocketing Covid-19 cases and dwindling personal protective equipment — a wrenching decision designed to protect patients, hospital staff, and the community at large based on evidence that the majority of those who are currently spreading the virus lack symptoms. Those restrictions were rescinded after an outcry from patients and the community, but the safety of allowing visitors into the hospital remains controversial.

Amid all this uncertainty and conflicting evidence, choices are rarely between a “good” option and a “bad” one. Instead, we have to choose the option that is least bad for the most people.

Despite the uncertainty, I am confident that we will get through, carried through by our willingness to adapt.

We cannot, for example, deliver essential services to pregnant people in the same way we did just a few weeks ago. Strains on the capacity of health systems and the need for social distancing have forced postponement and cancellation of prenatal appointments, and even surgeries. But these services are no less essential. We need to be ready to provide services in new ways. We need to redesign our protective equipment and approaches to infection control, expand our capacity to care for people outside the hospital, and enable virtual touch points with the health system wherever possible.

Equally important, all of us — scientists, health care workers, pregnant people, and the public — need to be willing to rethink what we thought we believed last week. We must approach this crisis with humility and empathy: be willing to listen to each other, to learn from each other, and to understand the perspectives others bring to the situation.

As we continue to make difficult decisions, we must remember that we are all in this together.

Neel Shah, M.D., is an assistant professor of obstetrics, gynecology, and reproductive biology at Harvard Medical School, an obstetrician at Beth Israel Deaconess Medical Center, and director of the Delivery Decisions Initiative at Ariadne Labs.

Republished with permission from STAT. This article originally appeared on April 11th, 2020

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