The B.C. government will update the population denominator used to calculate COVID-19 vaccine coverage percentages on Sept. 30, the first time it will update the figures since it began tracking the progress of COVID-19 vaccines.
The news of the Sept. 30 update came in a response to questions from revelstokemountaineer.com to the B.C. health ministry.
To calculate vaccine coverage in B.C. and by community, the B.C. government uses a figure dated on Mar. 12, 2021, despite the numbers, known as the Client Roster number, being based on a database that is updated by many healthcare workers daily. For example, when staff at a doctor’s office or hospital confirm your street address, that information is inputted into the provincial system based on the Medical Services Plan.
The update after more than six months, which has been hastily scheduled for National Day of Truth and Reconciliation when the focus will be elsewhere (c’mon), comes after an embarrassing mix-up that had health authorities claiming that people aged between 18 and 29 in Vancouver Coastal Health had achieved a 99% vaccination rate. Provincial health officials first backed up the claim, then walked it back.
Read this Twitter thread by CBC journalist Justin McElroy, who has been focusing on data analytics through the pandemic.
Here's a tiny story about everybody's favourite show: British Columbia, pandemic data, and government transparency.
Today's episode: the case of the 99% vaccination rate!
— Justin McElroy (@j_mcelroy) September 24, 2021
To calculate the percentage of a population that has received a COVID-19 vaccine, B.C. health officials do simple math: divide the number of people vaccinated by the total population to derive the percentage. You can do the same for individual cohorts, such as by age group or gender.
In a statement buried in the notes section on its COVID-19 vaccination tracking system, the BCCDC said that new registrations, the numerator, such as university students, had been added to the Client Roster system, pushing the total to 99%. (In fact, the BCCDC has updated the notes twice in the past few days. The first time they added the footnote noting the effect university students could have on a population, then later it added additional wording of “workers at major construction project areas.”)
However, health authorities had not been updating the denominator, the Client Roster, instead using the dated figure from March.
A mass vaccination campaign would likely push up the number of registrants in the Client Roster system, such as recent migrants to B.C. who register for the first time. By using a dated denominator from March, the effect is likely to make vaccination progress look better than it is. The effect is likely uneven by geography, creating more of an effect in locations with changing seasonal populations.
It’s not clear what effect the update will have, mostly because the health ministry has declined to provide updated numbers. For example, our request for the updated Revelstoke LHA Client Roster number was declined on Sept. 27.
(The health ministry does respond to our requests, but they often simply ignore the intent of the question, providing a response that does not answer the question. In this case, here was our question: “The denominator for the vaccination rate is the Client Roster number, which is based on MSP registrations. Currently, the government is using the Client Roster number from March 12, 2021. I have some questions and requests: 1. I am seeking the current updated Client Roster number for the Revelstoke Local Health Area as of the latest date it is available this month.” And here is the response from a health ministry spokesperson: “The current population figures used for tracking vaccination rates across B.C. remains those that were established on March 12, 2021.”)
What does it mean for a seasonal town like Revelstoke?
The Revelstoke Local Health area has been leading Interior Health in vaccination coverage since the start. Due to higher levels of COVID-19 activity in the community, health authorities allowed all persons aged 18 and over to get vaccinated from the start. That gave Revelstoke an early lead, and residents have kept Revelstoke at the head of the pack. Currently, for residents aged 12 and up, Revelstoke is listed as 92% coverage for the first dose of a COVID-19, and 82% coverage for the second dose.
From the start, the provincial government has emphasized the percentage number, and has been restrictive in providing the numbers upon which the calculations are based.
In order to get an accurate percentage, you need an accurate population denominator.
Based on the Mar. 12, 2021 date, health authorities say the total population of the Revelstoke Local Health Area is 9,426, making that the current denominator. It took weeks of persistent requests of multiple government health agencies to get that number this summer. That number covers Revelstoke and surrounding areas, including small communities. You can view a map of the Revelstoke LHA here.
However, that number is already significantly lower than a different population number the ministry uses to calculate COVID-19 infections. The infection rate uses the BC Stats PEOPLE2020 number, an estimate based on a number of sources that is updated annually. The number for the Revelstoke LHA is 10,696, a significantly higher number that would generate a lower percentage number.
So, what is the most accurate population number for the Revelstoke LHA?
In spring, as the public vaccination campaign was starting, revelstokemountaineer.com reached out to health authorities to establish what the population denominator is. Our main reason for seeking this simple public health information from government was the fact that it’s hard to know what Revelstoke’s population is at any given point in time due to our seasonality. The concern is the government may not have accurate numbers, and when they express progress in percentages, the numbers used to derive that calculation become important. The intent was to provide a better understanding of how government was dealing with this challenge.
As Revelstoke residents know, our population is seasonal, peaking in winter and summer, and the pandemic has created new demographic shifts. The City of Revelstoke has even contracted a TELUS data service to track all cell phone use to get an estimate better than dated Canada Census numbers.
Our question to the ministry: “What is the Client Roster total for all of B.C. as of Mar. 12, 2021, and what is it today or the latest date available?”
B.C. Ministry of Health response: “The Client Roster population total for all of B.C. that is used for vaccination rate coverage is 4,635,258 for 12 years and older. This continues to be the latest population snapshot available.”
Of course, it is not the “latest population snapshot available” on a real-time, digitized system; it’s that health ministry communications does not want to provide it now.
When they do, hopefully the updated numbers will not be out-of-date themselves, a recurring issue.
Analysis: The government communications’ urge to politicize basic public health information puts political considerations ahead of shared public scientific understanding in COVID-19 fight
In an unflattering analysis of the B.C. governments latest pandemic communications flops, including the revelation that it has systematically been underreporting COVID-19 hospitalizations (a story brought to light thanks to determined reporting by Penny Daflos of CTV), or its reversal on notifying parents of COVID-19 outbreaks at schools because notifying parents would create “anxiety,” long-serving Vancouver Sun columnist Vaughn Palmer sees a pattern in the government behaviour.
In his column, Mixed message on COVID-19 patients a blow to credibility of John Horgan’s government, Vancouver Sun, Sept. 27, 2021, Vaughn Palmer highlights the negative public health consequences to the B.C. government’s approach:
“Taken together, the systematic withholding of information may serve a political purpose of making B.C.’s record look better than it is,” Palmer writes. “But it risks undermining the government’s credibility: not just on the claim of openness and transparency, but on critical public health messaging like the safety of vaccines and the need for everyone to get vaccinated.”
From the perspective of a small media outlet in the remote Selkirk Mountains, we agree. Our question asking for a simple science fact — What is the population number you are using for the Revelstoke LHA? — ends up being a weeks-long, drawn out process involving dozens of emails to the local health authority and several provincial authorities. (At one point, the BCCDC provided us with a figure that was wrong, and later retracted that figure when we pointed out the math did not work using the figure they provided. They eventually sent us off to the Ministry of Health to ask them.)
Our intent in asking the question back in the spring was simply to clarify a key figure that we know is challenging to determine in our seasonal town, a number that other provinces openly disclose in convenient data apps. Instead of a straightforward answer to a basic question, the public servants in the communication departments opt to obfuscate and engage in pointless games that waste everyone’s time and dumb down the public dialogue in B.C.
When they finally provided it, they warned that the number was updated on a regular basis, so be careful when basing calculations on it. It turns out that it’s been the same number all along, something we discovered in early August after seeking the updated denominator then.
One result of the government’s communication approach is this story critical of the government, a story that is not helpful to current public health vaccination objectives because it will engender mistrust of health authorities among some readers, and one that would not appear here if the government communications infrastructure and political leadership prioritized a democratic public dialogue based on common understanding of basic facts.
To show we’re not the only ones lighting our beards on fire, we’ll leave you with another quote from Palmer’s column, this time commenting on this quote from the health ministry addressing why hospitalized COVID-19 patients were systematically excluded from COVID-19 hospitalization numbers reported to the public:
“This helps to understand the impact of the pandemic on the population (e.g., what percentage of people with COVID-19 require hospital care) and plan public-health measures,” claimed the ministry.
Palmer writes: “One shudders to think how long it took for the government’s vast communications apparatus to come up with a statement as worthless, as insulting, as misleading as that.”
It’s clear to Revelstoke residents that our population varies by season, and its also understood that measuring any population is a challenge that produces results that are never completely accurate, and people can understand a straightforward explanation of the facts. But when asked to explain how government was dealing with this challenge, the communications apparatus’s instinct is to obfuscate instead of just stating the facts.