Algorithm To Blame For Vaccine Invite Errors

Some islanders have been called early for a Covid-19 vaccine, while others have not received an invite when they should have, because of what has been described as 'anomalous results' from a computer system.

The States of Guernsey has been using an approved Public Health England algorithm to assign people to 'at risk' groups.

Priority Groups 4b and 6 of the vaccine programme are the 'clinically extremely vulnerable' and 18-65 year olds at 'moderate risk'.

An algorithm has been applied to the local health database of HSC and partner records to identify who should be included in those groups.  

"This algorithm allow large amounts of information to be quickly sifted to assess how likely an individual is to become seriously ill if they contract COVID-19. The algorithm does not apply clinical discretion in the same way a health professional might do, and instead highlights individual solely on the information available by searching for certain flags, or codes." - States of Guernsey

The authorities say this may present some anomalous results and that in a 'small number of cases may mean that some members of the community may be called slightly out of sync'.

A statement says: "We know using this algorithm could result in some people being missed or, as we know has happened, some people who are actually at low risk will end up jumping the queue."

It asks people to be patient, saying 'we know this isn’t perfect but we are getting through the groups as quickly as we can.'

The authorities say they are vaccinating more than 800 people a day for the next 3 or 4 weeks

They are also emphasising that the government has not been given any patients' private medical information by Primary Care Doctors.

"We know using this algorithm could result in some people being missed or, as we know has happened, some people who are actually at low risk will end up jumping the queue. But we need to focus on the positives of the situation we find ourselves in especially in the context of us entering the third consecutive week with no new cases.

An algorithm is able to search through data far more quickly than any human ever could. If we chose to, we could wait to push out this vaccine to medically at risk cohorts until the coding of every single medical record of all patients registered with a GP practice had been assessed and considered accurate. But that decision would cause a significant delay to the roll out of the vaccine programme and would be extremely costly. We are currently on schedule to ensure that everyone in priority groups 1 to 9 will have received their first dose of vaccine by 8 May 2021 and, for the benefit of our community, we would not wish to delay this unnecessarily."

Information from hospital clinics is also being used to identify patients that meet the criteria for groups 4b and 6.

People identified as higher risk who don't believe they are are being told they can still choose to accept the invitation:

"...for those of you who might be querying why you have been called up earlier than you were expecting it could be that many years ago you were prescribed some medication for something that has led to you being identified within the database as higher risk. This is nothing to worry about, especially if you don’t think of yourself as higher risk. If you have received an invite at this stage we will not be revoking it, please take the opportunity to  have your vaccine. Don’t feel that you are pushing others down the list. We have had to take a pragmatic approach to the situation we are in. We are progressing through the groups quickly and hope to be able to commence the second phase of the programme on or
around the 24 May 2021."

*Anyone wanting to delay to a later phase of the programme should call the Vaccination Contact Centre on 01481 707607 for that their records can be updated and an invite sent at the appropriate time.  Otherwise it will be assumed that you do not want to vaccine at all, and not further invite will be sent.

*Anyone who thinks they should be in Priority Group 6 and has not received an invitation letter should call 01481 707607 to discuss the matter.

*Anyone in groups 1-5 who thinks they have bene missed should call 01481 707607 to make an appointment.

Invitations for groups 6-9 are currently being sent out in batches, with 1,000 a day being posted this week.