There’s not much to update from last week; in fact — I assume that the health updates from here on out regarding COVID-19 may drop off. I’m going to space these updates out to every other week at this point.
Last week I wrote about the big question: when will we be done with this? When can we all come out of this stay-at-home stuff?
This week I want to take a second to deep dive into testing. I enjoyed doing a webinar last night for a small group of community members with a high-level discussion about testing in its current state in the KC area.
Broken down, here’s what we discussed:
How does one access COVID-19 testing?
- First, try reaching out to your primary care doctor.
- As a second option, there is very limited screening through the health departments
- I caution everyone to beware (of most) direct-to-consumer testing; many of these testing kits aren’t very accurate and (moreover) I would recommend having a physician you trust help you make decisions based on the results.
- Exceptions: both LabCorp and Quest have developed relatively decent tests that you can order directly from them.
- Lastly, hospitals are developing their own testing and are prioritizing hospitalized/critically ill patients and keeping their staff safe.
Is COVID-19 testing free?
- This is a complicated answer — but essentially someone is always paying for things (ain’t nothing in this life that’s free). If you have an Affordable Care Act-compliant insurance plan (i.e. if you bought it on the exchange or got it through your employer), the cost of processing the test itself is covered.
- There are some government grants that were included in the recent Coronavirus-triggered stimulus packages that may provide some payment for those who don’t have insurance — but the hospitals/labs/clinic have to apply for it (i.e. you can’t directly apply for help if you’re given a bil).
- Lastly, in line with our commitment to direct care without the intermediaries of insurers, we are offering the testing at our clinic — at a cost. We are covering the cost of our supplies with this fee.
What are the differences between the two testing types?
PCR/Molecular (Swab) | Antibody/Serology (Blood) | |
Goal | Diagnose those currently sick | Diagnose those previously infected |
Method | Nasal swab | Blood draw or finger stick |
Timeframe | Asymptomatic to 8D post-symptomatic | 5 days or more out (IgM)
10 days or more out (IgG) Best results 14+ days out |
Cost | $50-70 | $55-119 |
Turnaround | Minutes to days to weeks (depends on logistics, supplies, the specific lab company, and the acuity of the person being tested) | |
Accuracy | Loaded question; see the following question |
How accurate is testing?
- No test is 100% right all of the time. By virtue of how we design tests, there are always at least some false negatives and false positives.
- See the slides above. In the first slide w/ the graphs, you see that we have a population of people who are positive (denoted by the “+” sign). We want to test these people with a test to see if they’re positive — and we know that they are positive. We still have to pick some cutoff point where we can say that, for example, a test result of 99 is negative — but a test result of 100 is positive.
- In the next slide, the orange line shows this cutoff point. The blue triangle becomes those who have the disease but whose value — when tested — is below the cutoff point. Using the made up numbers above, these are the people whose test results are less than 100. That blue triangle is those who are labeled — falsely — as being negative and without the disease. They’re false negative lab results.
- So why not move the orange line to the left? Get rid of the false negatives?
- The next slide shows why!
- In the slide with the two hills showing those who don’t have the disease (denoted by the “-” sign) along the graph of those who have the disease (again denoted by the “+” sign), you see that that orange line actually creates some false positive results as well. Some people who are in the negative bunch — they do not have the disease — by virtue of the bell curve of any population, they’re lab values are going to come back over 100.
- If you move the orange line to the right or left, you create more false negative test results or false positive test results, respectively. Every lab test has this mathematical problem. Labs report this as sensitivity and specificity.
- What’s almost more important for COVID-19, though, is that this testing doesn’t happen in a vacuum. It happens out in the real world where some communities are seeing infection rates of COVID-19 into the 20-30% range while other communities are seeing rates much, much lower than that. When you test a population that — at baseline — doesn’t really have that much of a disease, you have a ton of people who just don’t have the disease. In absolute numbers, a community of 100 people with a 4% prevalence rate of COVID over the course of the pandemic will have 4 people who should truly test positive and 96 people who should truly test negative.
- And here’s where it gets tricky. As you can see on the last slide with the graphs, if you have a ton of people who are negative for a disease, but you test them anyway, you are going to get a lot of false positives. Just because there are simply more people in the negative group, so the number of false positives will increase proportionately. In the end, this can actually add up to a lot of people! And, in the case of COVID-19, it can be dangerous to both individuals and the community if people are going about their business thinking that they’ve already had the illness when, in fact, they’re just reacting to a false positive!
- TLDR? Testing isn’t great or super accurate — at least at this point. It will get better as more in the community contract the illness, for example, and as we learn more and have a chance to improve testing methods.
- (And in case I didn’t make it clear, my cutoff value above of 100 is totally made up for this example. Also, my graphs in the slides are made up and not to scale/don’t represent numbers. They’re just there to help visualize things!)
What do we do with the results of testing?
- We don’t know.
- We all want definitive answers, but the truth is that we really don’t know. Good science takes time.
- We can’t necessarily use antibody testing, for example, as it currently exists to figure out who can go back to work and who can’t (the so-called “immunity passport” concept). Why?
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- The tests aren’t that accurate.
- We don’t know if having antibodies (a positive test) means that a person is immune and can’t get re-infected. We may not know this for years and years.
- Furthermore, immunity passports create a perverse incentive for people to expose themselves to those ill with COVID-19 as a means to gaining this “passport” to work — which would not only endanger their lives but could overwhelm the healthcare system.
I hope this wasn’t too too dense and that it was somewhat helpful. We’ll move on, below, to the usual updates — and reach out if you have any questions or comments!
Allison Edwards, MD
Clinic & clinical updates:
- Please let us know if you have been impacted financially by the COVID-19 pandemic and need help with the cost of your monthly membership. We want to help you and are able to do so through the generosity of our KCDPC members. Just fill out and return this form — or just call us to talk about it (and we can help you through the technology).
- Though we are still here to care for you, as part of the stay-at-home order we may be working from home and condensing in-person visits (as needed) into a few hours a day; please call (913-730-0331) to confirm someone is at the office if you’re needing to physically swing by!
- There are currently two types of tests for COVID-19:
- Molecular (PCR) testing.
- We continue to offer this at KCDPC; it is $75 for the visit (and $50-70 billed by our lab vendor in several months). Anyone interested in getting tested must fill out this questionnaire before we are able to schedule your testing visit.
- Antibody (IgG/IgM) testing.
- This can be done via a car visit for KCDPC patients — and we recommend waiting at least 14 days beyond the resolution of symptoms before testing in this manner. Please call us to talk through logistics.
- Molecular (PCR) testing.
- If someone does test positive for COVID-19 via PCR swab (or saline rinse) and they are well enough to stay at home, they’re to quarantine at home and follow some basic guidelines to prevent the spread to others.
- Recommendations for when the general public can return to work after confirmed illness with COVID-19 are still shifting; the CDC has released guidance on how healthcare workers can be screened and cleared for return-to-work following illness. These guidelines are changing quickly, and we will help you through them if they end up applying to you.
- What’s less clear is when to return to work if you have respiratory symptoms but have either tested negative for COVID-19 or have been unable to be tested. The current recommendations are that you can return to essential jobs when:
- You have had no fever for at least 72 hours (that is three full days of no fever without the use medicine that reduces fevers)
AND - other symptoms have improved (for example, when your cough or shortness of breath have improved)
AND - at least 7 days have passed since your symptoms first appeared
- You have had no fever for at least 72 hours (that is three full days of no fever without the use medicine that reduces fevers)
- The basic facts about the virus remain unchanged: it is spread via droplet (and likely aerosolized in some situations), affects the elderly more frequently than the young (and affects people with conditions like high blood pressure, diabetes, heart disease, and lung disease far more severely than people who don’t have those conditions), and can be present — and transmitted — even in those who don’t have symptoms.
- There is no valid, evidence-based cure or treatment for the illness other than supportive care; however, scientific trials are ongoing across the US and the world.
- Remdesivir has shown some promise, potentially shortening the course of COVID-19 illness by 4 days.
- The NIH has consolidated the recommendations for treatment here.
- Vaccine development is still in the works but also takes time to confirm that it actually works and does not cause harm; this is still a long, long ways out.
- Seeing as we have no vaccine or clear treatment, the best plan is to protect yourself and prevent contracting the illness! If you must go out, try your best to keep a 6-foot radius from others. Better yet — stay home as much as possible and take advantage of delivery services or curbside pickup. Handwashing is essential, as is good rest, healthy eating, exercise, and all the usual best practices.
- This past week, the CDC update its recommendations regarding the use of face masks and is encouraging everyone to wear one (and even has instructions on how to make your own!)
- We have had some donations to the clinic of cloth masks; if you want one, please let us know and we can arrange for a clean, no-touch handoff!
Local updates:
- Both Kansas and Missouri are seeing their stay-at-home orders expire next week; several jurisdictions in the KC metro are extending their individual stay-at-home orders beyond the state’s expiration dates.
- Businesses on both sides of the state line have expressed anything from excitement to open back up to a tentative continuation of their closure as they see what happens next.
National political and economic updates:
- For tracking cases both worldwide and on a county level, we recommend the dashboard compiled by Johns Hopkins University of Medicine.
- The road ahead to “opening” the country is likely going to be bumpy; the Federal Government has consolidated its information for constituents here. Alternatively, you can check out information from the Centers for Disease Control, the National Institute of Health, the Food & Drug Administration, and the Department of Health and Human Services.