News Forum - First 10 days of February arrival figures for Thailand – Test & Go V2 “sluggish”

[vlad]

11 hours ago, Ksmui said:

It’s pretty clear that the military backed government doesn’t give a crap about the people and is using this as a tool to keep them suppressed. It is also clear that they do not want your average western tourist. They are only interested in letting in high dollar extremely wealthy individuals. It’s a Pennywise pound foolish approach that is harming the citizens that rely on tourism for years to come

Have you not read the headlines today on TT Ksmui ?  " Thailand hopeful to draw Indian Tourists with new travel bubble.

[Noble_Design]

10 hours ago, Skip said:

Actually, taking the test multiple times is similar to flipping a coin in the mathematical sense... each time that you flip a coin there is a fifty-fifty chance of a head or tail... each time that you take a covid test the probability is still whatever the current trend is... in this case 3.3%.

That's true... that means out of 1000 tests, 33 will be positive.

 

6 hours ago, Grumpyoldman said:

Firstly the tests have been proven very inaccurate with 30% false positives.

30% false positives? Really? Where's the source to that?

6 hours ago, Grumpyoldman said:

Secondly the big O is out there but doesn't make people ill, so you are likely to mix with seemingly healthy people who are infected.

Omicron doesn't make people ill? Really? What's the source for that?

The latest I saw in BP was that on Friday there are still 610 seriously ill patients (up from 569) and 128 dependent on ventilators (up from 113).

https://www.bangkokpost.com/thailand/general/2263127/16-330-new-covid-cases-25-more-deaths

6 hours ago, Grumpyoldman said:

Thirdly logic says the more you test the more likely you are to get a positive.

The 3.3% is not a progressive probability..... its not 3.3% of 3.3% of 3.3% etc. Its just 3.3%. So, have 30 tests over 30 days I would say almost bound to have a positive.

You're right, I think my previous formula is wrong. The correct one should be using a Binomial Probability:

https://www.varsitytutors.com/hotmath/hotmath_help/topics/binomial-probability#:~:text=Binomial probability refers to the,−p)n−x .

 

There is a good example for a binomial probability in that link that I provided so I'm going to adapt that to calculate the probability of getting 1 time positive Covid-19 if test 4 times.

 

What is the probability of getting 1 positive, when you test 4 times?

In a Covid test, there are two outcomes: positive and negative. According to the data provided in the article 3.3% tests positive which means the probability of being positive is 0.03

The number of repeated tests: n=4

The number of success trials: x=1 (Success means getting positive Covid)

The probability of success on individual trial: p=0.03

Use the formula for binomial probability.

4C1⋅(0.03)^1⋅(1−0.03)^4−1

Simplify.

≈0.1095 or 10.95%

Let's adapt that formula for 30 tests over 30 days:

30C1⋅(0.03)^1⋅(1−0.03)^30−1

0.372 or 37.2%

Not quite what you would call a certainty of testing positive but 37% is quite high of a probability.

5 hours ago, diegogg said:

Nope. That'll be the probability of testing positive all 4 times.

You're right, I made a mistake with the formula. Please refer to the above for the correct (I think) calculation

8 hours ago, Freeduhdumb said:

Ok I knew one of you smart statisticians would come along eventually and correct me... I knew it was something like this, but I couldn't resist going extreme and dramatic.. lol. 

I made a mistake with the formula, the probability of testing positive by the 4th test should increase, not decrease. Please refer to above calculations I did for grumpyoldman

 

Edited February 12, 2022 by Noble_Design

[CHAPPIE]

For sure the numbers will not increase after it was announced that Thai insurers are now not required to pay out on asymptomatic positive cases that are thrown into hospitel/prisons on a positive test result.                              We all know how easily a test result can be 'accidentally' reported as being positive.

[Cabra]

At ~5k per day, that's less than 2m in a year (extrapolated)... Seeing as there at about 3m legal expats in Thailand (at any given time; the majority being from Laos, Cambodia and Myanmar), I suspect all you are seeing is mainly expats traveling in-and-out to reconnect with loved ones or to work. The tourist trickle in with them but until quarantine (and insurance) requirements are dropped, I suspect a trickle is all that will dare the THA entry gauntlet.

[Grumpyoldman]

1 hour ago, Noble_Design said:

Omicron doesn't make people ill? Really? What's the source for that?

Well I was generalising to reflect that with Omicron most people, the vast vast majority, don't get symptoms or feel unable to continue their lives, unlike the other versions of the Big C, so you are most likely to mix with an infected person. If one has a sore throat or a sniffle, you aren't going to isolate for 14 days.... well I wouldn't anyway.

 

And, as usual, it's the unvaccinated and those with pre existing conditions who end up in hospital, so forgive me if I claim the Big O to be nothing more than a cold now for the 75-90% of people with vaccines or natural immunity.

 

Great maths lesson on this thread!

 

The Thaiger has allowed several people to have an online maths debate...... hope they don't get into trouble.

[Fundok]

21 hours ago, Does said:

It will be interesting to see the percentage of tourist who fail to show up on the fifth day for testing.   Of course nothing will be done to those who don’t get tested on day 5.  Why should they bother, as I have seen an influx of tourist not wearing masks in public. I heard one say, he doesn’t care and won’t wear a mask.   Just like driving in Thailand, there are no repercussions for those who fail to follow the rules 

I think the Thai authorities will not want to miss an opportunity to dish out fines. So I imagine that there will be repercussions.

[Fundok]

18 hours ago, ace035 said:

3.3% of incoming tourists tested positive for COVID-19 so which means Thailand already recouped the money that they lost by scamming and ripping off tourists so they satisfied by doing that. If it is less than 1% it's not enough, the rest of the tourists are heading to the Philippines or Cambodia.

"Of the 1,832 people that arrived and subsequently testing positive…

Russian 18.7%

Kazakhstani 7%"

 

So 25% of those travellers testing positive coming from those two jurisdictions. Maybe it would make sense to do something about that rather than making all travellers undergo that pointless test on day 5.

 

[Fundok]

4 hours ago, Pi_Tim said:

As long as the hospitel quarantine is mandatory for people who test positive, there will not be a surge in oversea tourism.

I am surprised that the survey does not mention this point.

There has been another tourist literally ripped off in Bangkok.

Tested positive on arrival, sent to hospital, with no symptom ! They imposed blood test, XRay, and tried to put him on antiviral. 11,600 THB billed per day !!

After 3 days, and because he refused the treatment and his insurance complained, he was sent to an hospitel, 10 days, 80,000THB !!

Total over 100,000 THB for 2 weeks in hospital/tels, with no symptom !!

Now, the guy has vowed to inform all his friends and families to avoid Thailand .... and he is not the first, neither the last one

(french article)

https://www.thailande-fr.com/tourisme/117753-covid-positif-en-thailande-le-temoignage-troublant-dun-francais

Interesting story. If TAT believes that under the current circumstances there will be a massive surge of incoming tourists they may as well believe in Santa Claus. In my view, it all seems to be so arbitrary once one tests positive. I mean: X-ray? Since when can you X-ray a virus? What about false positive tests? Any way to rectify that? My impression is: once you tested positive, you are helplessly in the hand of the Thai authorities and are just expected to pay, pay, pay.

[Chatogaster]

2 hours ago, Noble_Design said:

You're right, I think my previous formula is wrong. The correct one should be using a Binomial Probability

 

 

I'm a retired mathematician so this one tickled me.

Let p be the probability of testing negative (for the sake of the argument, I'll go along with assumption that p is a constant for all tests). There are only 4 cases in which a positive result can be obtained (N stands for negative, P for positive result):

NNNP ↔ probability = p^3 * (1-p)
NNP ↔ p^2 * (1-p)
NP ↔ p^1 * (1-p)
P ↔ p^0 * (1-p)

Note that a scenario like PPNP, i.e. first testing positive twice, then negative once, and finally positive again is not in the state space (since testing stops after 1 positive result) hence the binomial distribution does not apply.

Summing the probabilities above and dividing by 4 gives the average (1 - p^4)/4. Since p = 100-3.3% = 0.967, that amounts to 3.14% (what a nice result!).

However, that result means nothing as the premise about p being a constant is utterly ludicrous.

 

 

[riclag]

To all Russians, due diligence is your friend ! Try a less restrictive /covid fees playground !

[JJJ]

1 hour ago, Fundok said:

"Of the 1,832 people that arrived and subsequently testing positive…

Russian 18.7%

Kazakhstani 7%"

 

So 25% of those travellers testing positive coming from those two jurisdictions. Maybe it would make sense to do something about that rather than making all travellers undergo that pointless test on day 5.

What do these numbers mean? Is it (1) positive arrivals by country / total positive arrivals or is it (2) total positive arrival by country / total arrival by country.  

Saying 25% of arrivals presumes it’s number (1). But if it’s number (1) you can just add the numbers and see it will never get to 100%  

It’s not clear from the written description what the percentage means.

The positivity rate by country (#2) is the more useful number.

If it’s #(2) and Russians are the largest entry group, which they had been, then it’s easily 85% or more of arrivals testing positive came from Russia. We can’t say for sure without the proportional arrivals.  

Of course Tha would never consider risk-based rules, just throw all the farangs together. 
 

 

[Thommo]

3 hours ago, Noble_Design said:

That's true... that means out of 1000 tests, 33 will be positive.

30% false positives? Really? Where's the source to that?

Omicron doesn't make people ill? Really? What's the source for that?

The latest I saw in BP was that on Friday there are still 610 seriously ill patients (up from 569) and 128 dependent on ventilators (up from 113).

https://www.bangkokpost.com/thailand/general/2263127/16-330-new-covid-cases-25-more-deaths

You're right, I think my previous formula is wrong. The correct one should be using a Binomial Probability:

https://www.varsitytutors.com/hotmath/hotmath_help/topics/binomial-probability#:~:text=Binomial probability refers to the,−p)n−x .

There is a good example for a binomial probability in that link that I provided so I'm going to adapt that to calculate the probability of getting 1 time positive Covid-19 if test 4 times.

What is the probability of getting 1 positive, when you test 4 times?

In a Covid test, there are two outcomes: positive and negative. According to the data provided in the article 3.3% tests positive which means the probability of being positive is 0.03

The number of repeated tests: n=4

The number of success trials: x=1 (Success means getting positive Covid)

The probability of success on individual trial: p=0.03

Use the formula for binomial probability.

4C1⋅(0.03)^1⋅(1−0.03)^4−1

Simplify.

≈0.1095 or 10.95%

Let's adapt that formula for 30 tests over 30 days:

30C1⋅(0.03)^1⋅(1−0.03)^30−1

0.372 or 37.2%

Not quite what you would call a certainty of testing positive but 37% is quite high of a probability.

You're right, I made a mistake with the formula. Please refer to the above for the correct (I think) calculation

I made a mistake with the formula, the probability of testing positive by the 4th test should increase, not decrease. Please refer to above calculations I did for grumpyoldman

I should be worried then.  12 tests to date all  due to travel requirement with the 13th on Monday I guess i am Fxxked    fyi to date all have been neg

[Thommo]

2 hours ago, Fundok said:

I think the Thai authorities will not want to miss an opportunity to dish out fines. So I imagine that there will be repercussions.

What fines ?  lets be real   I have been fined twice for speeding in Phuket via a speed camera.  500  baht each time   my colleagues said dont pay no problem     FINES      

[LoongFred]

1 hour ago, Fundok said:

Interesting story. If TAT believes that under the current circumstances there will be a massive surge of incoming tourists they may as well believe in Santa Claus. In my view, it all seems to be so arbitrary once one tests positive. I mean: X-ray? Since when can you X-ray a virus? What about false positive tests? Any way to rectify that? My impression is: once you tested positive, you are helplessly in the hand of the Thai authorities and are just expected to pay, pay, pay.

Interesting, previously posters were complaining about the low numbers in Thailand now they are complaining a about false positives. If Thailand used a high cut off to reduce false positives the number of true positives will be lower not higher. 

Most posters here know nothing about testing, but this doesn't stop them from having opinions.

[BBY]

19 hours ago, Philly said:

1 of them told me he’s not taking a test before he flies home, I was like I’d be careful about that.

My question is would he be allowed to fly home?

That would depend on his own countries entry rules. Its likely that if his country require a test bettor he travels, that the carrier (airline) will want to see proof before they will check him in for the flight home. 

[FTF020]

hehe, I love the advanced math debate going on here. One thing though, you're using the % of travelers testing positive in Thailand and running the experiment 4 times. But the ones who test positive on the first experiment (aka the test before leaving your home country) will never make it to the thai statistics because they never were in the country.

 

General thought about the article, you could also argue that if you're not Russian/Kazach, and you're not on the same airplane/airport/van as them ($#%#$% Aeroflot, once but never again), your chances of testing positive are much lower?

[astro]

^

There is that.

Further, this is not a lottery where numbers are drawn - there the maths would apply.

It's a COVID test. Between the tests, people are exposed to different groups of people with an unknown infection rate. This gives incalculable odds.

[TimAn]

23 hours ago, Freeduhdumb said:

3.3% X 4 tests = a 13.2% chance of coming up positive on your holiday in Thailand?

Who teachs your Probability?  Your Mongolian physical education teacher？

The equation should be1- (1-0.033)^4=0.1256

 

[FTF020]

53 minutes ago, FTF020 said:

General thought about the article, you could also argue that if you're not Russian/Kazach, and you're not on the same airplane/airport/van as them ($#%#$% Aeroflot, once but never again), your chances of testing positive are much lower?

I gave this some more (shower) thought, and realized this is not right. Those 2 countries were also among the biggest contributors to the total number of arrivals. In fact, if they made up more than 25% of the total arrivals, they might be 'safer' than the rest!

[Freeduhdumb]

11 minutes ago, TimAn said:

Who teachs your Probability?  Your Mongolian physical education teacher？

The equation should be1- (1-0.033)^4=0.1256

As you can see, I made it pretty clear I knowingly wasn't going to be able to correctly do a calculation and knowingly wrote my calculation this way to get a response... the result of my comment is funny. Funny how many mathematicians there are out there and I don't believe we still have a consensus yet on the correct formula? Lol. 

"Ok I knew one of you smart statisticians would come along eventually and correct me... I knew it was something like this, but I couldn't resist going extreme and dramatic.. lol." -- Freeduhdumb

[TimAn]

2 minutes ago, Freeduhdumb said:

"Ok I knew one of you smart statisticians would come along eventually and correct me... I knew it was something like this, but I couldn't resist going extreme and dramatic.. lol." -- Freeduhdumb

GLHF

[Naanlaew]

2 hours ago, Chatogaster said:

"I'm a retired mathematician so this one tickled me."

 

 When they started combining the alphabet with the numerical system, That's where the troubles began.

 

 

Edited February 12, 2022 by Naanlaew

[francoa]

It is not gonna get better, but worst. Majority of EU countries are finished with covid, meaning, no masking at some, and normal life in basically every single of them. Why would anyone travel back to quarantine zone, pay vacation and be allowed to drink and party till 10:40 lol, with clubs, nightlife totally shut and still risking quarantine concentration camps lol

as west is freeing itself from the covid madness, thailand visitors will be less and less. 

[DougS]

I have not had a very good experience of the Test and Go scheme. I made my application 6 days ago after booking the appropriate hotels with PCR tests for days one and 5. Email received this morning rejecting my application as there had been no confirmation from hotels to the scheme that I had paid for accommodation and tests within the  30 hour limit they have. I've reapplied but I'm due to fly in 5 days. I'm afraid this is a bit of a mess. The usual pleasure I get from looking forward to a holiday replaced by the stress of dealing with a bureaucratic process that is out with my control. I've tried to get in touch with the hotels. One says they will respond this time. The other is not answering the phone and in email state no request for verification received. 

Very sad

 

[ace035]

9 hours ago, Pi_Tim said:

As long as the hospitel quarantine is mandatory for people who test positive, there will not be a surge in oversea tourism.

I am surprised that the survey does not mention this point.

There has been another tourist literally ripped off in Bangkok.

Tested positive on arrival, sent to hospital, with no symptom ! They imposed blood test, XRay, and tried to put him on antiviral. 11,600 THB billed per day !!

After 3 days, and because he refused the treatment and his insurance complained, he was sent to an hospitel, 10 days, 80,000THB !!

Total over 100,000 THB for 2 weeks in hospital/tels, with no symptom !!

Now, the guy has vowed to inform all his friends and families to avoid Thailand .... and he is not the first, neither the last one

(french article)

https://www.thailande-fr.com/tourisme/117753-covid-positif-en-thailande-le-temoignage-troublant-dun-francais

That's freakin insane, it's all about scamming and ripping off incoming tourists. A month ago, another tourist from this forum got scammed for almost B300K with asymptomatic or mild symptoms. I hope he/she does not have COVID-19 Thai insurance whether AXA, Tune IPass or Luma because he/she will not get reimburse after submitting the claim. If it is in Pattaya, they'll let them stay in hotel isolation with only expenses of B30K.