Debunking popular Covid-19 myths

Misinformation about Covid-19 spreads as quickly as the virus, through social media and even from government officials. We wanted to examine some popular myths about Covid-19 and see if there is any truth to these claims.

Myth: Doctors are inflating the number of Covid-19 deaths to get higher reimbursements

What’s the claim? President Trump claimed at recent rallies that doctors are exaggerating the number of Covid-19 deaths so they can get paid more.

“If somebody is terminally ill with cancer and they have COVID, we report ’em and you know doctors get more money and hospitals get more money. Think of this incentive,” he said.

What’s the truth? Hospitals do get a slightly higher reimbursement from Medicare for patients diagnosed with Covid-19. The CARES Act passed in March 2020 gives hospitals a 20% increase in payment for patients diagnosed with Covid-19. This was done so that hospitals could pay for protective gear for clinicians and other workers to care for these patients, at a time in which most hospitals were struggling financially. A September update from CMS advised that patients needed a positive Covid-19 test documented in their record to receive the reimbursement bump.

Does this policy give hospitals an incentive to test more people coming to the hospital for Covid-19? Maybe, but hospitals need to do this anyway to ensure the safety of their workers and make sure they are taking the proper protocols.

Does the policy create an incentive for doctors to lie about the cause of death for patients? No, it does not. Doctors recording when patients have Covid-19 cases for patients is not the same as doctors listing Covid-19 as the cause of death on a death certificate (more on that topic in the next question).

Why is the myth believable? Hospitals are known for squeezing as much from payers as possible, by documenting comorbidities wherever they exist. In rare cases, hospitals commit fraud like “upcoding,” billing an encounter as more serious or complex than it actually was. However, as Dean of Brown University’s School of Public Health Dr. Ashish Jha explained in an interview with StatNews, the likelihood that hospitals across the US are systematically coding patients fraudulently as Covid-19 positive is next to none. Not only is it immoral for hospitals to do this, it’s “super easy to get caught,” said Jha.

“We keep looking for these explanations when the explanation for 225,000 deaths and 8 million cases is pretty straightforward. We haven’t controlled the pandemic.”

Dr. Ashish Jha, Dean of Brown University’s School of Public Health

Why does it matter? Doctors reacted strongly to Trump’s claim, because they have been on the front lines of the pandemic, and in are shouldering a large burden of the virus response. Not only have they risked their lives, most physicians have had their pay cut during Covid-19.

Myth: Only 6% of Covid-19 deaths are actually due to Covid-19

What’s the claim? A popular argument on social media has been that reports of Covid-19 deaths are inflated because people are dying “with Covid-19” and not “because of Covid-19.” One claim that went viral on Twitter in September was that only 6% of Covid-19 deaths are actually due to Covid-19.

What’s the truth? In late August, a report from the Centers for Disease Control and Prevention gave a summary of Covid-19 deaths and comorbidities. The report showed that the vast majority of people who died of Covid-19 also had other documented conditions such as respiratory failure and pneumonia. “For 6% of the deaths, COVID-19 was the only cause mentioned.”

This does not mean that 94% of the people who are reported to have died of Covid-19 actually died of other causes. In the same way that HIV weakens the immune system and leads to life-threatening pneumonia and cancers, Covid-19 causes serious illnesses like adult respiratory distress syndrome (ARDS) and sepsis, which can be fatal. For most of the people that die of Covid-19, Covid-19 will not be the only condition listed on their death certificate, because the virus induces deadly conditions like ARDS. But make no mistake, Covid-19 is to blame.

For SARS-CoV-2, the assault it elicits on the lungs can greatly exacerbate other pre-existing conditions. So things like cardiac arrest, renal failure, liver failure, sepsis, lung scarring, etc. can all occur post-infection with SARS-CoV-2, leading to death. (3/4)

— Ryan McNamara 🧬 (@Ryan_Mac_Phd) August 31, 2020

It is also well established that having chronic conditions such as heart disease, diabetes, or kidney increases one’s risk of dying from Covid-19. This helps explain why so many people who have died of Covid-19 had comorbidities.

Why is the myth believable? We’ve heard a lot about asymptomatic Covid-19 cases, so it would make sense that some people who die of totally unrelated causes also happen to test positive for Covid-19. The instances in which someone died “with Covid-19” but not “because of Covid-19” are not unheard of (George Floyd is one example). But they’re not very common. According to Bob Anderson, chief of mortality statistics at the US Centers for Disease Control and Prevention, 92% of all deaths that mention Covid-19 list Covid-19 as the underlying cause of death.

“92% of all deaths that mention Covid-19 list Covid-19 as the underlying cause of death.”

Bob Anderson, chief of mortality statistics at the US Centers for Disease Control and Prevention

Why does it matter? The number of “real” Covid-19 deaths has been hotly contested from the start of the pandemic, because the higher the death rate from Covid-19, the more we need to take the virus seriously, and take action to reduce transmission. However, looking at the number of “excess deaths” shows that we are not underestimating Covid-19 deaths. From January to October, the US recorded nearly 300,000 more deaths than the typical number during the same period in previous years. About 2/3 of these deaths can be attributed to Covid-19, researchers estimate.

Myth: Masks don’t slow the spread of Covid-19

What’s the claim? Many in US do not wear masks because they don’t believe that they impact the spread of Covid-19. For example, the CDC’s finding that 71% of 150 people who contracted Covid-19 reported that they “always wore a mask,” has been cited as proof that masks don’t work.

What’s the truth? We know from many laboratory studies that wearing homemade cloth masks reduces the number of particles that are released into the air when we breathe, talk, and cough. In this way, cloth masks are recommended as a method of “source control,” helping to prevent the spread of Covid-19 from someone who has the virus to others. Because Covid-19 often spreads before someone shows symptoms, wearing masks in public is encouraged regardless of whether or not you feel sick.

Wearing a cloth mask may also protect the wearer from contracting the virus, or receiving a high viral load; however, cloth masks are not as good as surgical masks and N95 masks for this purpose, which is why it is recommended that health care workers wear more protective masks.

Besides laboratory studies, we have a lot of evidence in cohort studies, case studies, and epidemiological studies that find the masks reduce the spread of Covid-19. However, we don’t have any randomized controlled trials of masks for source control, which makes it difficult to know exactly how effective masks are at protecting ourselves and others from Covid-19.

“Clinical trials for non-pharmaceutical interventions in health are relatively rare because there is little to no money to be made from recommending them.”

Zeynep Tufekci, Atlantic contributor and Associate Professor of Sociology at University of North Carolina

While most public health experts agree that wearing a mask in public is a worthy policy given the minimal tradeoffs, some are also calling for the need for better evidence on the impact of mask policies. Doing cluster randomized trials to compare mask policies among various regions or schools would not only provide more evidence to support more mask policies, but also help us better understand some of the potential barriers to success or unintended consequences of mask mandates. For example, if masks are mandated, will people will engage in riskier behaviors because they feel more protected? Or will the mask mandate signal to the public that Covid-19 should be taken seriously and spur more social distancing? We don’t know the extent to which these and other factors could impact the effectiveness of masking on Covid-19 cases; more research could help answer these questions.

Why is the myth believable? Public health messaging around masks has shifted since the beginning of the pandemic. Most of us remember in March when the health officials urged people not to wear masks because they were “not effective.” The strategy was to avoid shortages of PPE for health care workers, but when the CDC changed course, some public trust was unsurprisingly lost.

Then when a study shows that 71% of people who wore masks still got Covid-19, it’s easy to think that masks are ineffective. However, analyzing studies like this requires a comparison with the control group. In the CDC study, 74% of people who did not get Covid-19 also wore masks. So there is not a significant association in either direction.

As many public health experts have pointed out, the primary purpose of cloth masks for the general public is source control, not personal protection. Your health may depend on whether those around you are wearing masks, not just whether you choose to wear one.

Why does it matter? Fewer aspects of the Covid-19 response has become more polarized than mask use over the past several months. As policymakers consider implementing mask mandates, advocates of masking should understand some of the arguments against masks and be honest about where we need more evidence, so we can find common ground.

Cardiologist Dr. John Mandrola put it well in a recent blog in Medscape:

“If we want people to wear masks, and we do, the answer is…to use the tools of any good doctor: humility, empathy, and common sense. The humility to tell people we don’t know—exactly—how much masks slow the spread of the virus. The empathy to say that we know that masks take away a lot of what makes us human. The common sense to say that masks are not dangerous, and, because mask-wearing probably helps reduce viral spread, and it isn’t forever, please, wear a mask—especially in confined indoor spaces.”