The 30 minute calculation David Ashford says is a “waste of resource” to calculate

During my morning coffee and news catch-up routine I came across this article from Manx Radio, published yesterday:

My first thought was, “hang on, didn’t the Treasury calculate this only weeks ago to figure out the cost of the testing for returning travellers, to explain why they pay for their own testing?”. Hmm.

So I have two questions:

  1. How did the Government calculate that covering traveller’s COVID tests would have costed £420,000 per month if the Government had paid for it?
  2. How much does a COVID test provided by the IoM Government actually cost?

I’m just about to start my morning coffee break. So for a bit of nerdy fun let’s see how long the “waste of resource” calculation takes me.

Question 1: How did the Government come up with the £420,000 per month figure?

This one is easy. The article from 20th January 2021 says that in “November and December the average number of people moving through the Island’s ports was around 700 a week“.

We’re calculating for a month (4 weeks), so 700 x 4 = 2,800 people.

When we divide £420,000 by 2,800 people we get £150, which is the cost of three COVID tests (day 1, 7, 13). This puts the cost of a test at £50, exactly what is charged to those people who are paying for the tests. NB, the day 1, 7, 13 testing regime didn’t start until 23rd December. The borders are now back to level 5 so very few people are now travelling via this route. The same testing strategy is not being used for residents who ring 111 and report being symptomatic, key workers on special testing pathways, or people being tested prior to a surgical procedure.

So to come up with this figure the Government just extrapolated from what they currently charge people for a test by the average travellers per week in Nov/Dec.

But this figure could change dramatically if the cost per test changes. This leads us onto the next question.

Question 2: How much does a COVID test actually cost the Isle of Man Government?

As I run a commercial molecular diagnostics company (i.e. we design, develop and deploy tests professionally) this is a standard calculation and one we carry out routinely. If we didn’t carry out these exact calculations for our suite of 183 PCR tests on a regular basis we wouldn’t still be in business. I would have expected the NHS to also know how much every test in a pathology lab costs and how many they carry out, if only to be able to budget accurately for the following financial year.

In the case of Isle of Man COVID testing, there is the cost of the PCR test itself, any equipment purchased, the staffing costs of providing the service and the cost of consumable items like swabs, pipette tips, tubes and other plasticware.

So let’s itemise all these things and calculate a figure.

I’m making a number of assumptions but always calculating the most expensive option for all assumptions made so the real cost per test to the NHS will be cheaper than any figure I end up estimating.

  • Assumption 1: 60 people per day being swabbed at the Grandstand. This number could be higher or lower but based on the current daily testing figures seems appropriate. Obviously, the more people who are swabbed the lower the cost of the swabbing facility is per test. These 60 people are returning travellers, people who ring 111 with symptoms, and those due to have a surgical procedure or other pre-booked hospital admission.
  • Assumption 2: 20 patients per day being admitted to hospital, or being prepared for transfer to a UK hospital are being tested with the 1 hour “rapid tests”. These tests are excluded from this calculation as the DHSC know how much each of these tests cost – approximately £100-120 per test – and how many they are using per day as they’re a limited resource.
  • Assumption 3: Commercial list prices for everything. However, the NHS can purchase much more cheaply than this through NHS supply chain.
(Assumptions and working out is listed below each item)
Price per test
Being swabbed at the Grandstand.
* 2 Healthcare assistants and two registered nurses running the drive-thru. Top end of band 3 (HCA) salary is £27k gross, Top end of band 5 (RN) salary is £37k gross. This equates to approximate gross cost per hour of £14.50 per hour (HCA) and £20 per hour (RN) based on a 37.5 hour week.
* Gross salary costs per hour for the team = £69/hour
* Assumes the DHSC are not paying rent on the grandstand, given the nature of the testing.
* £69 x 3 hours = £207. £207 / 60 patients swabbed = £3.45 per patient swabbed.
The swab used to swab the patient.
* Based on this price list (which will always be more expensive than the NHS can buy for) and rounded up by at least £1. The swab being used for COVID testing is product MW951S.
Isolating the viral RNA from the swab
* The only cost to the Isle of Man NHS here is the plasticware (pipette tubes, sample trays) as the pipetting robot was bought with Charity funds and the magnetic bead extraction kits are provided for free though NHS supply chain.
* Plasticware for 60 samples assumed to be 2 x Fisherbrand 1ml deepwell plates (£3.78), 1 x 200ul PCR plate (£4.46), 5 racks/refills of pipette tips (£18). Total for the RNA extraction run = £26.24
* £26.24 / 60 samples = £0.45. Let’s round that up to a pound to be on the safe side.
The COVID19 PCR test
* When Taxa Genomics was providing reagents the cost was £7.15 per test (which was three PCR tests in the same tube). I have it on extremely good authority that the current PCR in use at Nobles is a little cheaper than this (because it doesn’t test for the presence of human RNA to check the swabbing and reduce the false negative rate) so we can safely assume £6 per test or less.
* The PCR test will also require 1 x 200ul PCR plate (£4.46)
* £6 per test + (£4.46 / 60) = £6.10. Let’s round that up to £6.50 to be on the safe side.
* The real-time PCR machine was found in the Government Analyst’s lab and so was FOC. A larger machine with 4x capacity was purchased by a Charity in Aug/Sep ’20 but is not in use (i.e. all PCR equipment costs aren’t factored as they were free to the DHSC)
Pathology laboratory staffing
* Assuming a band 6 Biomedical Scientist (BMS) and a Band 3 Medical Laboratory Assistant (MLA) per day, exclusively working on COVID PCR testing. Top end of Band 6 BMS salary is £44k gross, top end of Band 3 MLA salary is £27k gross. This equates to approximate gross cost per hour of £24 per hour (BMS) and £14.50 per hour (MLA) based on a 37.5 hour week.
* Gross salaries for a day of testing with one PCR run = £288.
* Gross salaries per sample (assuming 60 samples per day) = £288 / 60 = £4.80.
* The cost per sample decreases the more samples that are processed

A few months ago I estimated (on the fly, on Twitter) that the cost per test was about £25, because that’s a comparable figure to our in-house testing here at Taxa. I would still say that now that I’ve spent 30 minutes doing the calculations, despite it coming out at £7 cheaper on calculating the list prices.

So at £25 per test I’m massively over-estimating the cost per test here. **It has been suggested on Twitter that I double the staffing costs (even though they’re based on maximum of salary band) to account for other costs. Fair enough, that takes the total test cost to £27 per test, which is a massive overestimation, on top of a costing that was wildly overestimated to start with.**

So why does David Ashford keep asserting that the cost per test is £100 and where is the other £75 per test being spent?

I’m genuinely intrigued!

p.s. this took me half an hour, including searching the job centre website for salary bands, suppliers for list prices and writing the blog post…

Leave a Reply