Coronavirus Risk Calculators: What You Need to Know
A screenshot of one coronavirus risk calculator.
People in my family seem to develop every ailment in the world, including feline distemper and Dutch elm disease, so I naturally put fingers to keyboard when I discovered that COVID-19 risk calculators now exist.
"It's best to look at your risk band. This will give you a more useful insight into your personal risk."
But the results – based on my answers to questions -- are bewildering.
A British risk calculator developed by the Nexoid software company declared I have a 5 percent, or 1 in 20, chance of developing COVID-19 and less than 1 percent risk of dying if I get it. Um, great, I think? Meanwhile, 19 and Me, a risk calculator created by data scientists, says my risk of infection is 0.01 percent per week, or 1 in 10,000, and it gave me a risk score of 44 out of 100.
Confused? Join the club. But it's actually possible to interpret numbers like these and put them to use. Here are five tips about using coronavirus risk calculators:
1. Make Sure the Calculator Is Designed For You
Not every COVID-19 risk calculator is designed to be used by the general public. Cleveland Clinic's risk calculator, for example, is only a tool for medical professionals, not sick people or the "worried well," said Dr. Lara Jehi, Cleveland Clinic's chief research information officer.
Unfortunately, the risk calculator's web page fails to explicitly identify its target audience. But there are hints that it's not for lay people such as its references to "platelets" and "chlorides."
The 19 and Me or the Nexoid risk calculators, in contrast, are both designed for use by everyone, as is a risk calculator developed by Emory University.
2. Take a Look at the Calculator's Privacy Policy
COVID-19 risk calculators ask for a lot of personal information. The Nexoid calculator, for example, wanted to know my age, weight, drug and alcohol history, pre-existing conditions, blood type and more. It even asked me about the prescription drugs I take.
It's wise to check the privacy policy and be cautious about providing an email address or other personal information. Nexoid's policy says it provides the information it gathers to researchers but it doesn't release IP addresses, which can reveal your location in certain circumstances.
John-Arne Skolbekken, a professor and risk specialist at Norwegian University of Science and Technology, entered his own data in the Nexoid calculator after being contacted by LeapsMag for comment. He noted that the calculator, among other things, asks for information about use of recreational drugs that could be illegal in some places. "I have given away some of my personal data to a company that I can hope will not misuse them," he said. "Let's hope they are trustworthy."
The 19 and Me calculator, by contrast, doesn't gather any data from users, said Cindy Hu, data scientist at Mathematica, which created it. "As soon as the window is closed, that data is gone and not captured."
The Emory University risk calculator, meanwhile, has a long privacy policy that states "the information we collect during your assessment will not be correlated with contact information if you provide it." However, it says personal information can be shared with third parties.
3. Keep an Eye on Time Horizons
Let's say a risk calculator says you have a 1 percent risk of infection. That's fairly low if we're talking about this year as a whole, but it's quite worrisome if the risk percentage refers to today and jumps by 1 percent each day going forward. That's why it's helpful to know exactly what the numbers mean in terms of time.
Unfortunately, this information isn't always readily available. You may have to dig around for it or contact a risk calculator's developers for more information. The 19 and Me calculator's risk percentages refer to this current week based on your behavior this week, Hu said. The Nexoid calculator, by contrast, has an "infinite timeline" that assumes no vaccine is developed, said Jonathon Grantham, the company's managing director. But your results will vary over time since the calculator's developers adjust it to reflect new data.
When you use a risk calculator, focus on this question: "How does your risk compare to the risk of an 'average' person?"
4. Focus on the Big Picture
The Nexoid calculator gave me numbers of 5 percent (getting COVID-19) and 99.309 percent (surviving it). It even provided betting odds for gambling types: The odds are in favor of me not getting infected (19-to-1) and not dying if I get infected (144-to-1).
However, Grantham told me that these numbers "are not the whole story." Instead, he said, "it's best to look at your risk band. This will give you a more useful insight into your personal risk." Risk bands refer to a segmentation of people into five categories, from lowest to highest risk, according to how a person's result sits relative to the whole dataset.
The Nexoid calculator says I'm in the "lowest risk band" for getting COVID-19, and a "high risk band" for dying of it if I get it. That suggests I'd better stay in the lowest-risk category because my pre-existing risk factors could spell trouble for my survival if I get infected.
Michael J. Pencina, a professor and biostatistician at Duke University School of Medicine, agreed that focusing on your general risk level is better than focusing on numbers. When you use a risk calculator, he said, focus on this question: "How does your risk compare to the risk of an 'average' person?"
The 19 and Me calculator, meanwhile, put my risk at 44 out of 100. Hu said that a score of 50 represents the typical person's risk of developing serious consequences from another disease – the flu.
5. Remember to Take Action
Hu, who helped develop the 19 and Me risk calculator, said it's best to use it to "understand the relative impact of different behaviors." As she noted, the calculator is designed to allow users to plug in different answers about their behavior and immediately see how their risk levels change.
This information can help us figure out if we should change the way we approach the world by, say, washing our hands more or avoiding more personal encounters.
"Estimation of risk is only one part of prevention," Pencina said. "The other is risk factors and our ability to reduce them." In other words, odds, percentages and risk bands can be revealing, but it's what we do to change them that matters.
Podcast: Trusting Science with Dr. Sudip Parikh, CEO of AAAS
The "Making Sense of Science" podcast features interviews with leading experts about health innovations and the big ethical and social questions they raise. The podcast is hosted by Matt Fuchs, editor of the award-winning science outlet Leaps.org.
As Pew research showed last month, many Americans have less confidence in science these days - our collective trust has declined to levels below when the pandemic began. But leaders like Dr. Sudip Parikh are taking important steps to more fully engage people in scientific progress, including breakthroughs that could benefit health and prevent disease. In January 2020, Sudip became the 19th Chief Executive Officer of the American Association for the Advancement of Science (AAAS), an international nonprofit that seeks to advance science, engineering and innovation throughout the world, with 120,000 members in 91 countries. He is the executive publisher of Science, one of the top academic journals in the world, and the Science family of journals.
Listen to the episode
Listen on Apple | Listen on Spotify | Listen on Stitcher | Listen on Amazon | Listen on Google
In this episode, Sudip and I talk about:
- Reasons to be excited about health innovations that could come to fruition in the next several years.
- Sudip's thoughts about areas of health innovation where we should be especially cautious.
- Strategies for scientists and journalists to instill greater trust in science.
- How to tap into and nurture kids' passion for STEM subjects.
- The best roles for experts to play in society and the challenges they face.
And we pack several other fascinating topics into our 35 minutes. Here are links to check out and learn more about Sudip Parikh and AAAS:
- Sudip Parikh's official bio - https://www.aaas.org/person/sudip-parikh
- Sudip Parikh, Why We Must Rebuild Trust in Science, Trend Magazine, Feb. 9, 2021 - https://www.pewtrusts.org/en/trend/archive/winter-...
- Follow Sudip on Twitter - https://twitter.com/sudipsparikh
- AAAS website - https://www.aaas.org/
- AAAS podcast - https://www.science.org/podcasts
- The latest issue of Science - https://www.science.org/
- Science Journals homepage - https://www.science.org/journals
- AAAS Mentor Resources - https://www.aaas.org/stemmentoring
- AAAS Science Journalism Awards - https://sjawards.aaas.org/enter
- Pew Research Center Report, Americans' Trust in Scientists, Other Groups Declines, Feb. 15, 2022 https://www.pewresearch.org/science/2022/02/15/ame...
An implant, combined with the glasses and tiny video camera modeled in this photo, could improve the eyesight of millions of people with degenerative eye diseases in the coming years.
For millions of people with macular degeneration, treatment options are slim. The disease causes loss of central vision, which allows us to see straight ahead, and is highly dependent on age, with people over 75 at approximately 30% risk of developing the disorder. The BrightFocus Foundation estimates 11 million people in the U.S. currently have one of three forms of the disease.
Recently, ophthalmologists including Daniel Palanker at Stanford University published research showing advances in the PRIMA retinal implant, which could help people with advanced, age-related macular degeneration regain some of their sight. In a feasibility study, five patients had a pixelated chip implanted behind the retina, and three were able to see using their remaining peripheral vision and—thanks to the implant—their partially restored central vision at the same time.
Should people with macular degeneration be excited about these results?
“Every week, if not every day, patients come to me with this question because it's devastating when they lose their central vision,” says retinal surgeon Lynn Huang. About 40% of her patients have macular degeneration. Huang tells them that these implants, along with new medications and stem cell therapies, could be useful in the coming years.
“The goal here is to replace the missing photoreceptors with photovoltaic pixels, basically like little solar panels,” Palanker says.
That implant, a pixelated chip, works together with a tiny video camera on a specially designed pair of eyeglasses, which can be adjusted for each patient’s prescription. The video camera relays processed images to the chip, which electrically stimulates inner retinal neurons. These neurons, in turn, relay information to the brain’s visual cortex through the optic nerve. The chip restores patients’ central sight, but not completely. The artificial vision is basically monochromatic (whitish-yellowish) and fairly blurry; patients were still legally blind even after the implant, except when using a zoom function on the camera, but those with proper chip placement could make out large letters.
“The goal here is to replace the missing photoreceptors with photovoltaic pixels, basically like little solar panels,” Palanker says. These pixels, located on the implanted chip, convert light into pulsed electrical currents that stimulate retinal neurons. In time, Palanker hopes to improve the chips, resulting in bigger boosts to visual acuity.
The pixelated chips are surgically implanted during a process Palanker admits is still “a surgical learning curve.” In the study, three chips were implanted correctly, one was placed incorrectly, and another patient’s chip moved after the procedure; he did not follow post-surgical recommendations. One patient passed away during the study for unrelated reasons.
University of Maryland retinal specialist Kenneth Taubenslag, who was not involved in the study, said that subretinal surgeries have become less common in recent years, but expects implants to spur improvements in these techniques. “I think as people get more experience, [they’ll] probably get more reliable placement of the implant,” he said, pointing out that even the patient with the misplaced chip was able to gain some light perception, if not the same visual acuity as other patients.
Retinal implants have come under scrutiny lately. IEEE Spectrum reported that Second Sight, manufacturer of the Argus II implant used for people with retinitis pigmentosa, a genetic disease that causes vision loss, would no longer support the product. After selling hundreds of the implants at $150,000 apiece, company leaders announced they’d “decided to pursue an orderly wind down” of Second Sight in March 2020 in the wake of financial issues. Last month, the company announced a merger, shifting its focus to a new retinal implant, raising questions for patients who have Argus II implants.
Retinal surgeon Eugene de Juan of the University of California, San Francisco, was involved with early studies of the Argus implants, though his participation ended over a decade ago, before the device was marketed by Second Sight. He says he would consider recommending future implants to patients with macular degeneration, given the promise of the technology and the lack of other alternatives.
“I tell my patients that this is an area of active research and development, and it's getting better and better, so let's not give up hope,” de Juan says. He believes cautious optimism for Palanker’s implant is appropriate: “It's not the first, it's not the only, but it's a good approach with a good team.”