Long lines at Covid testing sites have seen people turn to rapid antigen tests for convenient results in the lead-up to Christmas

As Covid case numbers continue to surge across the country and testing wait times blow out, people are increasingly using rapid antigen tests.

They are a convenient alternative to queueing for traditional polymerase chain reaction (PCR) tests and an extra precaution before attending gatherings in the lead-up to Christmas.

But with reports of shortages and varying levels of dependability, deciding what RAT kit to buy and when to use it can be difficult.

The federal department of health says rapid antigen tests are a faster way of getting a result, but don’t replace PCR tests.

So, which tests can you trust, and how much are they?

The Therapeutic Goods Administration (TGA) has approved 15 different rapid antigen testing kits, and categorised them according to their clinical sensitivity.

The TGA based its judgment of the performance of each kit on studies done by the manufacturer that show the positive percent agreement (PPA) – the percentage of individuals that produced a positive test result using a rapid antigen test, in comparison with a positive result by PCR test.

The TGA sets the minimum clinical sensitivity a testing kit must achieve before it is approved at 80%, which it labels as “acceptable sensitivity”.

A kit with 90% PPA is labeled “high sensitivity” and a kit that records clinical sensitivity greater than 95% is considered to have “very high sensitivity”.

There are only five kits that have been given the “very high sensitivity” label:

All Test Sars-CoV-2 Antigen Rapid Test (Nasal Swab)

Lyher Novel Coronavirus Antigen Test Kit (Nasal Swab)

OnSite Covid-19 Ag Self Test (Nasal Swab)

Panbio Covid-19 Antigen Self-Test (Nasal Swab)

V-Chek Covid-19 Antigen Test (Saliva)

The following have been given the “high sensitivity” label:

All Test Covid-19 Antigen Rapid Test (Oral Fluid)

Hough Covid-19 Home Test (Nasal Swab)

My Covid Test Antigen Rapid Test (Oral Fluid)

Orawell Covid-19 Ag Rapid Test (Saliva)

RightSign Covid-19 Antigen Rapid Test Cassette (Nasal Swab)

Testsealabs Covid-19 Antigen Test Cassette (Nasal Swab)

And finally, the tests rated as “acceptable sensitivity” are:

Roche Sars-CoV-2 Antigen Self Test (Nasal Swab)

InnoScreen Covid-19 Antigen Rapid Test (Nasal Swab)

Ecotest Covid-19 Antigen Saliva Test kit (saliva)

CareStart Covid-19 Antigen Home Test (Nasal Swab)

Although the varying degrees of clinical sensitivity are listed by the TGA, the University of Queensland infectious disease physician, associate professor Paul Griffin said any test approved by the TGA was worth using.

“I’d recommend anything approved by the TGA – we’ve seen throughout the pandemic, with regards to testing and vaccines, that they are incredibly rigorous.

“If they’ve approved it, and it is available, it’s a test I would endorse.”

But Griffin was quick to point out that rapid antigen tests don’t replace PCR tests, particularly for people with symptoms.

“These are really a useful additional layer of screening that we should certainly be using, but making sure we understand that the performance is not exactly the same as those laboratory-based tests.”

Rapid antigen testing kits cost roughly $10-20 per single test.

Tests have been available for purchase at chemists and supermarkets since November, with many sold in packs of two, five, 10 or more.

Considering businesses are responsible for purchasing their own testing kits, the costs can be substantial if workers need to get tested every day to protect themselves and their colleagues.

High demand has also reduced availability, with many retailers selling out, causing prices to fluctuate online.

The problem has been exacerbated by global supply chain issues that are delaying shipments of the tests into Australia.

Business and union groups have called for the government to fund or subsidise tests, to allow greater accessibility.

The Council of Small Business Organisations Australia (Cosboa), along with the Australian Council of Trade Unions and the Transport Workers’ Union, have also called on the government to intervene.

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“Some people may say $15 a pop is not expensive, but if you’re running a hairdressing salon with 20 people on different shifts throughout the day [it can add up],” Cosboa chief executive, Alexi Boyd told the Guardian.

“We just need as many options as possible,” Boyd said. “Nothing is the golden ticket out of this but we need as many pieces of weaponry against it as possible.”