How to interpret the TGA’s Authorised Prescriber figures

Cann Group senior corporate communications manager Rhys Cohen dives into the TGA’s new Authorised Prescriber dashboard and comes up with one overwhelming conclusion – the industry is booming.

The Therapeutic Goods Administration’s medicinal cannabis Authorised Prescriber data dashboard has been released, providing new insights into patient access trends in Australia. According to the dashboard, there have been 292,033 “new patients initiated on treatment” and 527,614 “total patients treated” since 2016.

But these figures are not what they appear to be. To properly interpret them, we must first understand how they are collected and reported. This takes some careful, detailed explanation. So, if that’s your thing, please read on.

First, we need to re-cap the November 2021 reforms to patient access processes, and the five medicinal cannabis product “categories” that were created. If you’re already familiar with this, you can skip forward to the next section.

How medicinal cannabis product categories work

Prior to November 2021, to prescribe a medicinal cannabis product, doctors were required to get a SAS-B approval, or become an Authorised Prescriber (AP). SAS-B approvals were product, patient, and indication-specific. So, for the SAS-B pathway, if you wanted to prescribe a specific product, to a specific patient, to treat a specific medical indication, you needed a SAS-B approval. And if you wanted to prescribe a different product, to the same patient, to treat the same indication, you needed another SAS-B approval. SAS-B approvals were (and still are) required before a prescription could be filled, so using that pathway required quite a bit of ongoing paperwork.

That’s why becoming an AP was attractive. As an AP, you could be authorised to prescribe a specific product to an approved class of patients (eg. adults) directly under your care, to treat a specific medical condition, without needing the TGA to approve each individual patient.

Unlike the SAS-B pathway, which required a new approval (and new paperwork) for each product, patient, and indication, APs were only required to report twice a year to the TGA informing them of how many patients were treated in the prior six months. But if the product you were authorised to prescribe went out of stock (which was, and still is, common), or you wanted to prescribe a new product that just hit the market, you needed to use the SAS-B pathway.

Becoming an AP required more paperwork and processing fees up front, but meant less ongoing paperwork. To become an AP, you needed to be endorsed by a Human Research Ethics Committee (HREC). But while there are plenty of HRECs, very few were prepared to endorse medicinal cannabis prescribers. The vast majority of APs got endorsed by the HREC at the National Institute of Integrative Medicine, with applications costing A$800 and taking at least eight weeks to process, depending on when the committee was scheduled to meet.

Then the TGA determined that this product-specific approach imposed too much paperwork on prescribers so, in November 2021, they changed the system. Instead of SAS-B and AP approvals being product specific, the TGA sorted all medicinal cannabis products into five categories according to relative THC/CBD content, like this:

• Category 1: at least 98% CBD
• Category 2: less than 98% and more than 60% CBD
• Category 3: less than 60% and more than 40% CBD
• Category 4: between 60% and 98% THC
• Category 5: more than 98% THC

From November 2021, instead of getting a SAS-B or AP approval for a specific product, you could get an approval for specific categories of products (as above) and product formats (eg. oil, flower etc). So, as an AP, instead of needing approval for a laundry list of products, which quickly went out of date when new ones came onto the market, you could be authorised to prescribe any products within specific categories and specific product formats, for specific medical indications.

For example, an AP might be authorised to prescribe category 1 oil products for the treatment of chronic pain. And if a new category 1 oil product came onto the market, you could go ahead and prescribe it right off the bat. This made the AP pathway much more user friendly and attractive to prescribers.

The TGA also made it much quicker, easier, and cheaper to become an AP for certain lower-risk treatments. They determined that oil or capsule products, when used to treat adults for either chronic non-cancer pain (if in categories 1, 2, or 3) or anxiety (if in categories 1 or 2), had an “established history of use”. This meant that doctors could become APs for these products without first needing to pay hundreds of dollars and wait several weeks for an HREC endorsement. They could apply directly to the TGA and get their AP status in a matter of days, and at no cost. The number of doctors using the AP pathway shot up as a result, going from under 200 in the first half of 2021 to nearly 600 in the second half of the year, and nearly 900 in the first half of 2022:

How APs report the number of “patients treated”

Let’s focus on how AP reporting works now, following the November 2021 changes. Here is a scenario: a patient (let’s call her Susan) sees an AP (let’s call her Dr Carter) in January 2022. Dr Carter writes Susan prescriptions for the following products:

• One CBD isolate oil (category 1)
• One CBD broad spectrum oil (category 1)
• One balanced oil (category 3)
• One balanced capsule (category 3)
• Four different high-THC dried-flower products (category 5)

When Dr Carter completes her six-monthly report to the TGA in June 2022, she should report the number of “total patients treated” as four, even though she prescribed eight different products, from three different categories, across three different product formats, to only one patient.

This is because “total patients treated” represents the number of patients the AP has treated with a product:

a) From a specific product format, and
b) from a specific medicinal cannabis product category.

For Susan, the calculation would look something like this:

(This is not the format in which APs are required to report to the TGA, it’s just easier to explain it this way. If you want to see how the AP reporting system actually looks, that’s available here).

APs are also meant to specify which of these “patients treated” are new. In our example, Susan saw Dr Carter for the first time in January 2022, so when Dr Carter completes her six-monthly report to the TGA in June 2022, all of Susan’s treatments are new. Dr Carter would report the number of “total patients treated” as four and would also separately report the number of “new patients treated” as four. That would look something like this:

Let’s assume Susan comes back for a follow-up consultation with Dr Carter in September 2022. Susan has filled and used up all her prescriptions, and Dr Carter decides to write new scripts for all of the products she prescribed back in January. Except one of the flower products has been discontinued, so she prescribes a different category five flower product instead.

When Dr Carter completes her six-monthly report in December 2022, she would report the number of “total patients treated” as four. Dr Carter has previously prescribed Susan with products from the same categories and formats, so she would report the number of “new patients treated” as zero.

This would also be the case if Susan was continuing to take her medicinal cannabis products, but didn’t need any new prescriptions. Dr Carter should include Susan in her “total patients treated” for the duration of Susan’s treatment, not just when she writes new scripts.

But here’s where it gets tricky. The next year, Susan visits Dr Carter again and some of the products just haven’t been working as well as they used to. Dr Carter determines that the two CBD oils she had prescribed should be replaced by a different product with a little more THC.

Dr Carter writes new prescriptions for the same flower, capsule, and balanced oil products Susan was already taking. But instead of the CBD isolate and CBD broad spectrum oils, Dr Carter prescribes a single 20:1 CBD:THC oil, which falls into category 2. The calculation for this reporting period would look something like this:

So, even though Dr Carter has been prescribing medicinal cannabis products to Susan for over a year, because she has just prescribed a product from a different category/format for the first time, that will show up as a “new patient treated” in the AP data.

Problems with the AP data

If your eyes glazed over while reading the explanation above, imagine how a busy doctor must feel. Why should Dr Carter report four “total patients treated” when she’s only dealing with Susan? If Dr Carter has been treating Susan for over a year, how does it make sense to start reporting her treatments as a “new patient”? It’s hardly intuitive.

Being an AP requires Dr Carter to not only understand these nuances, but also to record and store accurate records of how Susan’s prescriptions should be reported to the TGA. Imagine if, in two years’ time, Dr Carter wants to prescribe a new product to Susan which requires her to go back over years of prescribing records to figure out if this prescription should count as a “new” patient or not. Then consider the fact that doctors who become APs are probably prescribing medicinal cannabis to quite a few of their patients. Or, if they work for a medicinal cannabis clinic, the vast majority of their patients. Would it matter if Dr Carter made an error in her TGA reports? Would anyone notice?

If you look at the AP data portal, you might notice some anomalies: for example, between January and June 2021, the number of “new patients initiated on treatment” was 119,285 while “total patients treated” was 112,334. How is it possible that the total number of patients treated is less than the number of new patients during that period?

I asked the TGA this question, and a spokesperson replied:

“Please be advised that the TGA has no control on these figures as they represent the self-reported numbers submitted by the Authorised Prescriber for the reporting period as a part of their AP six-monthly reporting obligation.

However, during compliance checks, if it comes to our attention that the submitted numbers do not appear accurate, for example, as you have indicated, the reported number of new patients initiated on treatment is greater than the total number of patients treated, an educational email will be sent out to the Authorised Prescriber on the correct method for patient reporting.”

So, we really have no idea how complete or accurate the TGA’s AP data might be. If an AP should have reported 1,000 “new” and 2,000 “total” patients, but only reports five “new” and 10 “total”, no-one would be any the wiser. But if they reported 10 “new” and five “total”, they might get an “educational email” from the TGA.

On top of that, AP data has other shortcomings: a patient might receive prescriptions for eight products, but only fill some or none of them; or see two different APs in the same six-month period, and so appear twice in the data; or see a doctor who prescribes them some products via their AP authorisation, and others via the SAS-B pathway, and so appear in both AP and SAS-B data; or get a script with 10 repeats, and not need a new one for a year or more, making them invisible.

The phrase “garbage in, garbage out” comes to mind. But we make do with what we have, and despite these limitations, there are still useful insights we can draw from the data.

AP data trends by category

The November 2021 reforms appear to have shifted prescribers away from the SAS-B pathway and towards the AP pathway. One of the downsides of this shift is that SAS-B data is more detailed than AP data. For each SAS-B approval, we know the month it was issued, the gender and age of the patient, the product format, and medical indication involved.

For AP “patients”, we only know the six-month period within which that treatment occurred, and the category of the product involved. We have no idea about gender, age, product formats or medical indications. So, if we want to dig down into the AP data, we can look at “new” versus “total” patients (which is so messy that it’s essentially worthless, at least for now), or we can look at the categories of products involved.

This data is also messy due to the November 2021 changes. All doctors who have become APs after November 2021 will automatically go into the new system, but there are still APs who received their authorisation under the old system and are yet to transition across. So, for “patients” treated under the new system, we know which category of product they were prescribed. And for those treated under the old pre-category system, we don’t.

If we just look at “total patients”, we can see that from July-December 2021, 76% of treatments occurred via the old, pre-category system. And then, from January-June 2022, this shrunk to 18%. Meanwhile, the proportion of category 5 “patients” grew from 7% to 29%.

But remember, for most of H2 2021, categories didn’t even exist yet. If we want to identify any trends in the relative growth of categories, we need to get rid of the pre-category data. If we do that, the picture looks quite different.

Take this with a big pinch of salt, because we are now comparing about 25,000 “patients” from 2021 against about 285,000 from 2022. We should wait until the data from the second half of 2022 is published before drawing any strong conclusions. But it is interesting that the relative proportion of category 5 “patients” appears to have grown over time. This would be consistent with the growth in the dried flower market that has been observed since 2020.

It is also interesting to note that during H1 2022, at least 47% of “patients” were treated by an AP with an HREC endorsement, so the sudden growth we have seen in the AP data since November 2021 is not just being driven by APs prescribing high-CBD and balanced oil and capsule products that have an “established history of use”.

Comparing AP data to SAS-B data

There are lots of problems with both AP and SAS-B data, but at least they’re similar problems, so it should be possible to compare them to look at overall patient access trends. Similar to our AP data, SAS-B approvals are (since November 2021) patient, category, and format specific. But there is one main difference between these data sets.

Let’s say that Susan visits Dr Carter in January 2022, but Dr Carter isn’t an AP, she is using the SAS-B pathway. And to make things simple, Dr Carter only prescribes Susan one product: a category 1 oil. In the SAS-B data, this would show up as a single SAS-B approval in January 2022. Susan comes back to visit Dr Carter every four weeks, and Dr Carter keeps writing prescriptions for the same product.

By default, SAS-B approvals are valid for two years. So, even though Susan is actively taking a medicinal cannabis product, and seeing her doctor frequently, she would show up in the SAS-B data as a single approval, until January 2024 when the approval expires and a new one is required. Unless Dr Carter prescribed a new product, from a different category/format, which would require a new SAS-B approval.

Alternatively, if Dr Carter was an AP, Susan would show up as a “new patient” in the first six-month reporting period, and a “total patient” in every subsequent reporting period. Over the next two years, instead of one SAS-B approval, she would show up four times in the AP data.

You might think this means one SAS-B approval should always be equivalent to four AP “patients”. But imagine that Susan only visited Dr Carter once, and never filled her prescription. In the AP data, Susan would appear once as a “new patient”, and then vanish. And in the SAS-B data, she would appear as a single SAS-B approval in January 2022. If we assumed Susan’s SAS-B approval was worth four AP “patients”, we would be very wrong indeed.

Following this logic, it does seem that, on average, one SAS-B approval – potentially representing up to two years of continuous treatment – is probably “worth” more than one AP “patient”. By how much, though, is a mystery.

There’s also the problem of accounting for the November 2021 reforms, which reduced how many SAS-B approvals or AP “patients” are required to facilitate the same amount of access, meaning that after November 2021, these figures should be “worth” more than before. On the other hand, it’s possible that, as the market has matured, it has become more common for patients to be prescribed multiple different products at once. Anecdotally, that seems to be true, and would mean that SAS-B approvals and AP “patients” should be “worth” less than before. But once again, we don’t know by how much, and this is all speculation.

With that in mind, if we wanted to take a conservative view of the growth in patient access over time, combining both SAS-B and AP data, we could do that using the following assumptions:

• One SAS-B approval is worth three AP “patients”
• If new AP “patients” exceeds total AP “patients” in a six-month period, take the smaller number
• The value of SAS-B approvals or AP “patients” has remained constant over time
• Sum all SAS-B approvals issued in a six-month period to allow comparison to AP data

This analysis might be way off in either direction. And we still don’t know how many real patients, or how much actual cannabis, this represents. But however you cut the data, and whatever conclusions you draw from it, one thing seems clear: the Australian medicinal cannabis industry is booming.