On 2020-04-06 11:13:41, user japhetk wrote:
I think this is another voodoo correlation study of BCG which keeps appearing one after another. BCG may be effective or not effective, but that cannot be revealed by country analyses due to many uncontrolled and complex factors.
The problems of this study's analyses, they are not controlling when the infection spread in the country properly.
Other analyses are controlling that (for example, number of patients (or deaths) 10 days after the 100th patients were detected, was used as a dependent measure). In this study, only the 3 categorical classification is used, which is apparently not appropriate nor objective.
Also, probably, the most accurate available BCG measure is "how long the country has advanced the BCG vaccination measure" (the year when the country stopped the BCG vaccination (or now, when the BCG vaccination is currently conducted in the country) - the year when the country started it). UK for example, advanced BCG for more than 50 years, so the majority of the have been experienced with BCG. So, the "current" "past" "never" classification is not appropriate.
I controlled these measures and have done the analyses.
The results were as follows.<br />
The partial correlation between "how long the country has advanced the BCG vaccination measure" and number of patients in the 10th day (when 1st day is 100th patients were detected in the country) after controlling the population of the country. P = 0.455, partial correlation coefficient = -0.116).
The partial correlation between "how long the country has advanced the BCG vaccination measure" and number of deaths in the 10th day (when 1st day is the 100th patients were detected in the country) after controlling the population of the country. P = 0.111, partial correlation coefficient = -0.243).
But the partial correlation between "how long the country has advanced the BCG vaccination measure" and when the 100th patients were detected in the country after controlling the population of the country was P = 0.078, partial correlation coefficient = 0.281.
Also "how long the country has advanced the BCG vaccination measure" is robustly and negatively correlated with GDP of the country after controlling the population of the country (p = 0.019, partial correlation coefficient:-0.292).
But the correlation between GDP of the country and when the 100th patients were detected in the country after controlling population of the country was more robust (p = 0.001, partial correlation coefficient: -0.438)(the greater the GDP, the faster the 100th patients appeared).
And the correlation between "how long the country has advanced the BCG vaccination measure" and when the 100th patients were detected in the country disappeared when the population and GDP is also controlled (p = 0.322).<br />
Most of correlations are tendencies levels and disappeared or substantially got weaker after GDP is controlled.
So, my guess is probably, there are number of spurious correlations going on authors' analyses due to lack of important control variables.
The higher GDP countries can do more tests, they are more popular from the <br />
tourists from Asia, but they were less inclined to use masks as far as I heard and less alert.
The list of potential confounding variables, as far as I can see is endless and diverse.<br />
Such as numerous nutritional components, the foods of western rich countries include.<br />
The temperature. <br />
How many Chinese (ratio) is included in the nation (apparently Taiwan, China (except Wuhan) and other countries where Chinese consist most of nations were as alert as possible). <br />
Preference of wearing masks.<br />
Popularity of religion. (Religious ceremonies are cited as the popular source of the cluster of infections).<br />
The strength of individual rights and freedoms.<br />
The factors related to Western rich countries.
In the case of Diamond princess, Japanese was apparently not invincible.<br />
About 300 patients were Japanese and 180 patients were from Western rich countries in the case of this ship, and among them, 7 Japanese died and 2 from Canada and UK died. Japanese were not biological invincible from this coronavirus, please stop spreading this rumor through country based correlation studies… Just please wait for RCT studies.