The Dogma of the Realities of the Accuracy of SARS-CoV-2 Tests!

SARS-CoV-2, the virus responsible for the COVID-19 pandemic, is a new/novel virus for the human race. One of the pillars of managing this virus and the pandemic is accurate testing. Testing for the SARS-CoV-2 virus remains a challenge with regards to the accuracy of tests on the market. Epidemiologically, any diagnostic or laboratory test is always evaluated on two key metrics: it’s specificity and sensitivity rate.

Specificity

Specificity is the likelihood that the COVID test results are truly positive. That is, could a similar Non-COVID-19 Coronavirus be responsible for the positive result? A COVID test with a high specificity (i.e., reliable) will have a LOW false positive rate. Generally speaking it is desirable to have a test with high specificity. However, high specificity is attained at the expense of sensitivity. It is desirable to have a test with high specificity and sensitivity, but almost impossible to create a perfect test.

SARS-CoV-2 in its worldwide prevalence in the general population is still low. Even with the current pandemic raging, the prevalence and incidence is still low based on identified active cases (Some 5 million active cases identified worldwide out of a population of about 7.7 billion as of May 21, 2020). Aside from the diagnosed positive cases, it is estimated that the prevalence of coronavirus infection is more around 5% in the general population. We commonly associate a low prevalence of disease with increased false positive rates when testing. The current low prevalence of COVID infection affects the accuracy of SARS-CoV-2 tests coming into the market for use, with the risk of false positives becoming a major problem. Test manufacturers and regulators alike will have to be diligent and guard against a high number of false positives when developing and approving tests.

Sensitivity

Sensitivity of a SARS-CoV-2 molecular test or antibody test is the likelihood of how accurately the test will detect the virus or presence of the different types of antibodies. That is if you are infected with the virus, will the test correctly identify that you are infected, or will it not identify the virus in your respiratory system, resulting in a false negative. A highly sensitive test (i.e., accurate) will have a LOW false negative rate.

Most of the tests granted emergency use approval by the FDA during this pandemic have limited data with regards to their reliability and accuracy. Scientists at the Cleveland Clinic found that one popular rapid genetic test (the widely promoted Abbot test) told users they didn’t have the virus when they actually did (false negatives) about 15 percent of the time (1). Meanwhile, researchers at UCSF California studied 14 antibody tests on the market, some that were granted emergency use authorizations by the Food and Drug Administration (FDA), and found that only three of these tests delivered consistent results (1). Given the 5% prevalence rate, if a serological test has about 90% specificity, its positive predictive value (PPV) will be 32.1% – meaning nearly 70% of positive results will most likely be false. At this same disease prevalence, a test with 95% specificity will lead to a 50% chance that a positive result is wrong. Only at 99% specificity does the false positive rate become anywhere near acceptable, and even here the chances are that 16% of positive results would be wrong.

We know that a number of individuals with COVID infection are asymptomatic, sometimes for weeks, increasing the transmissibility of the disease in the population. For such cases it is important to have tests that can look for active infections with a high degree of sensitivity and specificity (low number of false negatives and false positives). If we can quickly identify such cases and isolate them, then we can prevent the rapid spread of this contagion.

The table below summarises test accuracy data, as of May 06, 2020, from selected manufacturers for their serological Covid-19 tests. However, when reviewing this data it has to be stressed that the validation tests these companies have performed have varied widely in size; Abbott’s antibody assay was tested on 1,200 specimens, whereas Epitope’s tests were run on only 54 samples from healthy people, and just 20 and 30 cases of PCR-confirmed Covid-19 cases for the IgM and IgG tests respectively.

Accuracy & Reliability of Selected COVID 19 Tests in the US & EU Markets:

[table id=3 /]

Note: All accuracy claims made by the companies. *Tests with FDA emergency use authorisation. Source: EvaluateMedTech & company websites.

Similar to most processes associated with COVID 19, since the emergence of the infection, tests for active infection and/or for antibodies are evolving daily by different clinical research laboratories, academic health organizations, and biomedical companies worldwide. However, in the US we are still facing a challenge with regards to ready and widespread availability of accurate and reliable COVID tests for both the molecular PCR test and the serological tests for the different antibodies. The situation is both dire and murky to say the least.

At this point, it is well recognized that both the molecular tests for Covid-19 (the nasal PCR that look for active infections) and the serological antibody tests (IgM for more recent and IgG for past infections) have had significant issues with respect to their accuracy. Shortage of good tests in turn means that we will not know how many active cases are out there in the public, or how many have recovered with a degree of short or long term immunity conferred on them to decrease the risk of contraction and/or rate of reinfection.

REFERENCES
1. https://www.vox.com/2020/5/1/21240123/coronavirus-quest-diagnostics-antibody-test-covid
2. Data compiled by EvaluateMedTech.
3. Loeffelholz MJ, Tang YW. Laboratory diagnosis of emerging human coronavirus infections – the state of the art. Emerg Microbes Infect. 2020;9(1):747–756. doi:10.1080/22221751.2020.1745095
4. Sheridan C. Fast, portable tests come online to curb coronavirus pandemic. Nat Biotechnol2020. [Epub ahead of print] doi:10.1038/d41587-020-00010-2 pmid:32203294

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FAQ

What services are provided as a part of my annual fee?
  • Same-day or next business day appointments
  • Direct access to Dr. Espinosa via his personal cell phone after hours, weekends, and holidays
  • Minimal office wait times
  • Longer, more comprehensive appointments
  • House Calls (requires additional trip fee)
  • A strong focus on preventive medicine, long-term health and wellness
  • A personal professional relationship with your physician
What is the mission of Buckhead Medicine?

We strive to provide the highest quality medical care, emphasizing a comprehensive approach to prevention and disease management. We want patients to be completely satisfied with every aspect of their care.

Where is your office and are you on the medical staff of a local hospital?

Yes, Dr. Espinosa’s office is in Buckhead, a suburb of Atlanta. He is on the medical staff of Piedmont Hospital in Atlanta, Georgia and Northside Hospital in Atlanta, Georgia. If you require hospitalization, Dr. Espinosa will coordinate your patient care by working with the hospital based physicians. He will also make periodic hospital visits during your hospitalization.

Who will cover for you when you are not available?

On infrequent occasions when Dr. Espinosa is out of town or otherwise unavailable, he will have another qualified physician cover for him. Even while out of town, Dr. Espinosa will generally be available by phone to his patients and to his covering physicians. For practical reasons, we reserve the right to designate another qualified physician to perform any and all services should the need arise.

Do you accept insurance?

Commercial Insurance and Medicare:
Buckhead Medicine is an In-Network provider for Blue Cross Blue Shield PPO, Aetna, Coventry, Humana, Cigna, Tricare and United Healthcare. Our practice fully participates in the Medicare program. Buckhead Medicine accepts all other insurance as an Out-of-Network provider. We, however, do not participate in the Medicaid program. Regardless of your plan, we will bill your insurance for all covered services. It is our intention that no insurance-covered medical services are included in your annual fee.

HMO and Medicare HMO:
We do not participate in HMO programs. As such, HMO patients will not be able to join the practice until they transition to either a PPO or traditional Medicare plan.

Do I still need insurance if I enroll with you?

Yes. Personalized medical practices do not take the place of general health insurance coverage. Buckhead Medicine is a primary care medical practice, not a health insurance program. You are advised to continue your PPO, Medicare or other insurance program. If you are an uninsured individual and desire to enroll in the practice, we will provide you with a discounted fee schedule for office visits, tests and procedures.

What if I don't have health insurance?

For uninsured patients, Buckhead Medicine offers an uninsured patient plan. Although this plan is not insurance, it does cover for all clinic visits and any labs or tests that are performed in our office. In many cases this plan provides for significant cost savings to uninsured individuals. Please contact our office for additional details on this plan.

Will my insurance still be billed for my office visits?

Yes, we will bill your insurance company directly. The annual fee does not cover costs for regular exams or testing conducted inside or outside of the clinic. These costs are billed to your insurance provider in the same manner that traditional practices bill insurers.

Is there a co-payment?

If you have commercial insurance, we will collect the co-payment at the time of service. Medicare patients usually do not require a co-payment.

Do you bill Medicare for the annual fee?

No. The annual fee is not covered by Medicare. The fee only includes services that are not covered by Medicare and, as such, cannot be paid for or reimbursed by Medicare. We will bill Medicare for your sick visits and for any additional services performed at this practice that are covered by Medicare.

Will my commercial insurance reimburse my annual fee?

No, commercial insurance does not typically reimburse for the annual fee. However, some Flexible Spending Account and Health Savings Account plans may pay for all or part of the annual fee. In addition, some insurance plans allow the concierge fee to apply towards the annual deductible. Members are advised to consult their human resources representative at their place of employment.

Is the annual fee tax deductible?

In many cases the annual fee is a tax deductible healthcare expense. Patients are advised to consult with their tax consultant to clarify qualification in their particular circumstance.

Does the annual fee cover lab, x-ray, specialist fees and hospitalization?

Services such as labs, x-ray, specialty visits or hospitalizations are covered based on coverage determined by your insurance plan.

Are there age limits?

Dr. Espinosa is an Internal Medicine physician. His specialty is Adult medicine. Dr. Espinosa is trained to manage acute and chronic medical illnesses among adults. As such, the practice is limited to patients 17 years of age and older.

What if I have an emergency?

If you have a life threatening emergency, call 911 immediately. After you call 911, please call Dr. Espinosa. He will contact the hospital and notify the emergency room of your tentative arrival. In addition, Dr. Espinosa will provide the emergency room with pertinent medical history information

How far in advance do I need to book an appointment?

Dr. Espinosa is committed to providing his patients with easy access to care. All urgent visits will be accommodated either same day or next day, placing the greatest priority on the sickest patients. Annual physical exams will be booked 1 to 2 weeks in advance.

What do I do if I become ill while traveling or away on an extended vacation?

Call 911 if you have a life threatening emergency. Then call Dr. Espinosa. Call Dr. Espinosa first if the problem is minor. With the exception of a few controlled substances, most prescriptions can be ordered anywhere in the country. If necessary, it may be possible for Dr. Espinosa to find you a resource in your area. If you seek care at an emergency room or urgent care center out of our area, we request that you have the doctor seeing you call Dr. Espinosa for coordination. Dr. Espinosa will be readily available by phone for consultation with you and/or other health care personnel. If you should require hospitalization while away, at your request, Dr. Espinosa will establish phone communication with you and your attending physician(s) to ensure continuity of care.

Do you make house calls?

House calls will be available to Buckhead Medicine members, within a limited radius from the clinic. These will be done as deemed appropriate by Dr. Espinosa on a case-by-case basis. Home visits will be billed to your insurance provider similar to an office visit. A separate trip fee is required for house calls.

What if I need to see a specialist or a surgeon?

Of course, Buckhead Medicine patients are free to see any specialist they wish. We are available to help you decide what specialists to see and to coordinate such consultations. Patients may frequently request for “doctors in my area”, and we can accommodate this. We will ensure that the most appropriate resources are used, the earliest arrangements are made, and your applicable medical information is sent in advance of your specialist visit.

What about the cost of prescription medications?

The cost of prescription medications are the patient’s responsibility and in most cases should be covered by their insurance plans. We have expertise in assisting patients in purchasing medications in the most cost effective manner.

Will I be required to pay my annual fee even if I do not use your services?

Yes. Paying your annual fee allows you to be a member of the practice whether you are sick or well. We encourage our patients to utilize the amenities offered such as wellness consultations and emails for appropriate non-urgent health related questions, regardless of your state of health.

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