Mistaken beliefs and abusive policies

Published in Expansión

 

Politicians insist on torturing us with facemasks, but the scientific evidence is skeptical about their effectiveness. If in March the Journal of the American Medical Association said that “there is no evidence to suggest that facemasks worn by healthy people are effective in preventing people from getting sick with respiratory infections.”[1] a recent Cochrane review (highest level of medical evidence) of several trials conducted to measure the efficacy of physical barriers to the spread of respiratory viruses concludes that “wearing a surgical mask may make little or no difference in the outcome of influenza-like illness compared with not wearing a mask (…) and in the outcome of laboratory-confirmed influenza,” estimating a low degree of certainty in the first conclusion and a moderate one in the second. It further concludes that “the use of an N95 mask compared with a medical/surgical mask is likely to make little or no difference in laboratory-confirmed influenza infection”[2]. The first randomized controlled trial on the actual efficacy of surgical masks versus covid has been conducted in Denmark[3]. The result? 1.8% of those wearing them became infected with covid versus 2.1% of those who did not wear them, a statistically insignificant difference[4]. If these are the data for the surgical masks, go figure the effectiveness of the cloth ones. On the other hand, scientific evidence (and common sense, by golly) dictates that it is highly unlikely to catch covid outdoors[5]. Remember that during the lockdown the sidewalks of Spain were crowded with people without masks walking side by side in narrow time slots and contagions continued to decrease. On the other hand, we have suffered mandatory masks for six months now and the virus has been circulating much more freely than we have been allowed to by the government’s tyrannical restrictions. However, politically, the masks’ farce serves a double function: first, it places the focus of blame on the population (particularly on the young, the official scapegoat), becoming an ideal instrument to exonerate the authorities from any responsibility; second, its abusive imposition in absurd situations (in an uncrowded street[6] or alone, or in the countryside) is a symbol of submission, a rule of etiquette of the good and obedient subject, just as under the communist dictatorship of Mao Tse-Tung it was well seen (and sometimes obligatory) to wear the “Mao suit” as a symbol of proletarian uniformity and submission to the regime. This farce is not harmless: it is doing real mental damage and making neurotic those who confuse the witticisms of devious politicians with scientific reasons. The most glaring example is the people who drive alone and wear masks anyhow.

The January-February media terror campaign has made fashionable the English strain (one more of the many variants of the coronavirus), “discovered” by the flamboyant British Prime Minister in December when he claimed it was “70%” more contagious. In reality, the strain had been circulating since September and there was no clear scientific evidence to support that figure, pulled out of the hat, or a greater lethality, as denounced by several virologists[7]. In fact, what is relevant is not a disease’s contagiousness, but the probability of it becoming severe. A month and a half later, the British “experts’ committee” (SAGE) has issued a paradoxical note in which it acknowledges that previous studies concluded that there was no increased risk of hospitalization or death from the new strain, but that three more recent studies, “with potential biases and limitations”, did. However, it reiterates that “there is no evidence of increased lethality of the new variant in hospitals”[8] It also estimates a probability of less than 50% (a confidence level only one degree higher than “unlikely”) that the new strain is more lethal and emphasizes that absolute mortality remains “low” (CFR less than 0.2%, i.e. 99.8% of those diagnosed survive). Therefore, unless there is new evidence, and given that it was a politician (needless to say more) who used the “news” as a deflector shield to evade responsibility for an increase in cases and justify the imposition of a new and extremely unpopular lockdown, a healthy skepticism, formed in the school of successive and unfounded terror campaigns, invites to consider doubtful the alleged dangerousness of the “English” strain of the “Chinese” virus (soon to be replaced by the Brazilian, South African, etc. strains).

Likewise, the media-politics’ cabal takes as a reference variable the number of infections (even if they are just mild cases) instead of the number of deaths, canonizing PCR tests and misinterpreting their results. What is the probability that a person chosen at random from the overall population is perfectly healthy after testing positive? The answer is not intuitive and is certainly not the “false positive” figure of less than 1% (specificity greater than 99%) offered by the manufacturers and wrongly repeated by many physicians. The statistically correct answer is between 45% and 85%, because the probability of having the flu if you have a headache is not the same as the probability of having a headache if you have the flu. Indeed, we are dealing with a case of conditional probability where Bayes’ Theorem applies, so that the positive predictive value of the test, that is, the probability of having covid having had a positive result, is a function, above all, of the a priori probability of having the disease, which for a person chosen at random is equal to the proportion of the population ill at the time of the test (prevalence). The lower the a priori probability of being ill, the higher the probability of true false positives (on the contrary, in people with covid-compatible symptoms the probability of false positives drops sharply). Thus, with pristine false positives and negatives of 1% (specificity and sensitivity of 99%) and a prevalence of 1% (higher than the current prevalence in Spain), the probability that a person chosen at random does not have covid with a positive PCR would be 50%. This would be the case, for example, of someone who goes to a hospital for foot surgery and has a PCR performed ex officio. And since in the real-world protocols are not followed and samples are contaminated, the real specificity[9] and sensitivity[10] are lower than the theoretical ones and the probability of erroneous positives[11] could reach 85% in certain cases. A couple of weeks ago, the WHO itself warned that “the probability that a person with a positive result is actually infected with SARS-CoV-2 decreases as prevalence decreases, regardless of the stated specificity,” and clarified that PCR assays are merely indicated “as an aid to diagnosis” and should therefore be combined with “clinical observations, patient history, confirmed status of any contacts and epidemiological information.[12]” Given that Bayes’ theorem has been known for 260 years, it is surprising that it has taken WHO so long to publicly warn of these excesses after numerous articles in The Lancet and others[13]. PCR also does not distinguish between active virus and inert, innocuous viral matter, so even a true positive may not be contagious at all. Some scientists, in fact, call PCR (somewhat exaggeratedly) “useless”[14].

Responsible behavior based on scientific evidence and focused on protecting the population at risk is crucial to combat the epidemic, since for the vast majority of the population covid is a mild disease. But faced with the abuse of the political class, with artificially created hysterias and absurd, unscientific and harmful regulations that are ruining entire families, imposing a suffocating tyranny and creating massive cases of mental disorders and depression, are we free citizens or submissive and masochistic vassals?

 

Fernando del Pino Calvo-Sotelo

 

www.fpcs.es

 

[1] Medical Masks | Infectious Diseases | JAMA | JAMA Network

[2] Do physical measures such as hand-washing or wearing masks stop or slow down the spread of respiratory viruses? | Cochrane

[3] Landmark Danish study finds no significant effect for facemask wearers | The Spectator

[4] Effectiveness of Adding a Mask Recommendation to Other Public Health Measures to Prevent SARS-CoV-2 Infection in Danish Mask Wearers: A Randomized Controlled Trial: Annals of Internal Medicine: Vol 0, No 0 (acpjournals.org)

[5] Indoor transmission of SARS-CoV-2 (medrxiv.org)

[6] Questions and answers on COVID-19: Prevention (europa.eu)

[7] Irish scientists play down concerns over new coronavirus strain in UK (irishtimes.com)

[8] NERVTAG paper on COVID-19 variant of concern B.1.1.7 (publishing.service.gov.uk)

[9] False positives in reverse transcription PCR testing for SARS-CoV-2 (medrxiv.org)

[10] False Negative Tests for SARS-CoV-2 Infection — Challenges and Implications | NEJM

[11] Interpreting a covid-19 test result (bmj.com)

[12] WHO Information Notice for IVD Users 2020/05

[13] False-positive COVID-19 results: hidden problems and costs (thelancet.com)

[14]Review report Corman-Drosten et al. Eurosurveillance 2020 – CORMAN-DROSTEN REVIEW REPORT

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