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Testsealabs COVID-19 Rapid Antigen Test Nasal 20 Count $144.99 @ Costco (Membership Required)

350

Saw these tests available at Costco Ringwood. Plenty in stock, but one per membership card.


Mod Note: TGA - Evidence of performance against Delta.

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  • +2

    Price is good but this one is just high sensitive
    https://www.tga.gov.au/covid-19-rapid-antigen-self-tests-are…

    • +2

      Please educate me. So we should be looking for “very high sensitivity “? In short, the higher the sensitivity, the better?

      • +1

        The higher sensitivity, the more accurate the test is likely going to be.

        • Thanks.

        • Yes, Accurate implies detection rate. However in this case it doesn't mean detection rate.

      • -3

        Sensitivity does not equal detection rate. lol. Too many people think it does.
        The real way to interpret sensitivity is if it is high sensitivity, then if you tested positive on it, then you are >90% chance you have COVID.

        • +4

          Actually that's not quite correct. Sensitivity is the likelihood that if you have the disease you will test positive. A low sensitivity means an increased risk of false negatives (that you have the disease but test negative). You are referring to the positive predictive value of a test. https://uk.cochrane.org/news/sensitivity-and-specificity-exp…

          • @constipated: So why has the detection rate been reported for RAT tests as being less than 50% for non-symptomatic and only 70% for symptomatic cases?
            Why don't they just make it very clear instead of using all this medical jargon to try to hide the detection rate?

            Why do the government tell close contacts to RAT test 2-4 times (depending on which state) within a week if the sensitivity meant detection rate?

            People will probably think i am against RAT tests, but I'm actually for them (when they aren't price gouged). The more testing we do the better it is, but we also at some point will just need to accept that we are now at the stage of coming out of a pandemic, and covid will be endemic.

            • @lplau: There are 2 concepts with medical tests. Sensitivity is how likely, if you have the disease D+, are you going to test positive T+. Specificity is how likely, if you don't have the disease D-, are you likely to test negative T-.

              Another way of thinking about it is if you have a very sensitive test, you will have fewer false negatives. If you have a very specific test, you will have fewer false positives.

              Every test has to be taken in the context of how likely you are to have a condition because every test has an error rate (false positives and false negatives) which doesn't change. What changes is how likely you are to have the condition tested for.

              These tests test for virus proteins, if you are symptomatic, it is reasonable to say that your likelihood of having COVID is higher, so the test is more useful.

              Why weren't we using these tests really early on in the pandemic when we were having only 10s of cases a day. That's because the likelihood of a true infection was so low, that for every true positive you picked up, it was likely to be outnumbered by false positives that had ramifications like needing to be contact traced.

              Now the pendulum is way on the other side. People have a very high chance of being infected when they take the test, true positives will outnumber false positives.

              Put another way. One of the TGA tests has 90% sensitivity but 99.5% specificity.
              At the beginning of the pandemic when only 0.1% of people taking a test actually had COVID, if you got a positive test, then only 15.25% of those tests where actually truly positive (positive predictive value). That is 85% of people who got a positive result actually wouldn't have the infection.

              Now that 40% of people who take the test actually have COVID, if you get a positive test, then 99.2% of those people will truly have COVID. Only 0.8% of those who get a positive result don't have the infection.

              Therefore positive predictive value changes dramatically based on how much of the disease there is around.

              https://epitools.ausvet.com.au/predictivevalues

            • @lplau: No ones hiding anything, its just complicated and nuanced.

      • +1

        Clinically specificity above 98% (ie below 2% false positives) and 95%+ positives accurately identified

        • Great explanation!
          Haha which shows the flaws of RAT Tests and how people are so ill-informed.

          Still good to have around, but make sure you are informed. Because I've had friends and family who had very minor symptoms, and they said "Its ok I have used a few very high sensitivity RAT tests and showed negative, therefore i have more than 95% chance of not having COVID" lol.

          The RAT test manufacturers have worded it so carefully, so it implies detection rate, but none of the numbers even describe detection rate at all. And the government isn't doing anything about it to make it clearer.

          • @lplau: Very high sensitivity is indeed 95%+, so I guess they're technically not wrong lol

            Not quite how statistics works with multiples and edge cases though

            • @[Deactivated]: The problem with all the numbers is taken from people who tested positive using a RAT test. Not on the detection rate.
              You can have 100 people who is COVID positive using PCR, but only 50% of them actually tested Positive using RAT test.
              So they base the numbers off the 50% who tested positive using the RAT test, and disregard the other 50%.

              So as long as 95% of the 50% of people who tested positive to PCR and RAT test comes back as positive on RAT test, then they rate it as very high sensitivity. lol.

              • +1

                @lplau: The statistics are more the below

                Of 100 that do test positive, 80, 90 or 95+ were earlier correctly identified by the rapid test (depending on the test)

                Using the same rapid test kinds, below 2% were identified incorrectly of having it

                You're like correct the 98% / 2% test had safe guards for those who delayed or never got a PCR and the other test didnt, but that's why one is 80-95 and one is 98 lol

                (How people interrupt the numbers is for them - don't mean to defend the use of rapid tests or defend against their use)

                • +1

                  @[Deactivated]: Oh, I'm not telling people not to use RAT tests. More testing the better and catching them earlier is better.
                  Although the government can start investing in other testing types like LAMP testing which has proven to cost around the same as a RAT test and ALOT more accurate.

                  Quicker than PCR tests with almost the same detection rate. Also MUCH cheaper in terms of equipment than PCR tests and comes back within 30minutes or so. PCR is still the gold standard, however we don't really have a middle standard now, we either got Gold Standard or Low Standard. LAMP tests are only about 3-4% lower detection than PCR but 40+% higher detection rate than RAT tests.

                  I see the future as workplaces which require frequent testing will likely start doing LAMP tests, as some of them can be done even with a Cellphone and chemical reagents.

          • @lplau: If you have done a few tests in a row, its pretty much certain.

    • Those sensitivity are just self-reported anyway. Do you trust a Chinese manufacturer's self-reported data? Look how credible Chinese made "KN95" masks are - not very. 
      https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-si…

      About 60% of KN95 respirators NIOSH evaluated during the COVID-19 pandemic in 2020 and 2021 did not meet the requirements that they intended to meet.

  • -3
    • +4

      I don’t think that’s quite right. It just hasn’t been proven to the TGA that it can detect omicron yet? It doesn’t mean that it won’t.

      It’s still listed as high sensitivity on the TGA website. If they thought it couldn’t detect omicron, I assume they’d recall it given omicron is 97% of the cases here.

      • The sensitivity rating is that reported by the manufacturer. It isn't very useful.

        While this statement is on the TGA website, it is a sensitivity reported by the supplier, it is NOT independently tested by the TGA.

        The below table provides an indication of the performance of COVID-19 rapid antigen self-tests, including information on the clinical sensitivity of each test. This is based on the studies performed by the manufacturer which show the positive percent agreement (PPA).

        • I didn’t know that, but I still think It’s better than nothing. I guess you could choose to think they’re lying or inaccurate results, but I’d like to hope they’re legit.

          • +1

            @woka: Likely to be legit, but if you read enough of how they test it and there is no real standardization of testing for these.
            There is so many conditions and caveats that real life % may vary heaps.

            Also there is conditions such as transportation and storage which takes into play, especially when they have been sitting in a Hot summer truck for hours during transport. Since they don't transport these in cold storage.

            I'm not saying to not do RAT tests, but just take a negative result from a RAT test with a grain of salt. If you feel ill, then either stay home or get a PCR done (if your RAT showed negative).

  • bought one box of 20 All test oral test kit for $160 from Costco Lidcombe yesterday.

  • Which ones are more accurate? These testes, or the clunge ones?

  • +2

    Ozbargainer detected: https://imgur.com/a/EjRoSeP

  • Just some anecdotal experience using rat test and omicron, I used a rat test when i got covid it came out positive did a pcr after(positive again).
    So i am not sure why people are saying it doesnt work with omicron ?

    • Its likely because the detection rate of RAT tests aren't that great. Its less than 50% detection rate of COVID (of any strain) if you dont have symptoms, and around 70% detection rate if you have symptoms.

      There is a reason why close contacts in certain states have been mandating 4 RAT tests for 1 week if you are a close contact. If the detection rate wasn't so poor, they wouldn't even need you to take more than 2 tests!

  • Not sold out yet wow

  • I bought these last week and they definitely detect Omicron. My son had Covid last week.

    • And how do you know your son had omicron, not delta?

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