I watched 7News on Monday night, and in a piece of footage in that newscast, a simple question was posed to the representative from the Ministry of Health and Wellness. However, despite being asked multiple times, she refused to answer whether COVID tests of tourists who are leaving the country are included in the daily reports. In an era of mistrust, the spread of misinformation (or no information if you simply pull the plug —-see Press Office and Commission incident!), which was already serious before COVID, is now a matter of life or death (think of the anti-vaccination information being circulated, the promotion of “miracle cures” such as vitamin D, hydroxychloroquine and ivermectin). MOHW has to answer the question to ensure that we all have confidence and faith in official statistics. What is the point of telling us that the positivity rate is 0.45 if we cannot understand what it is measuring? You might as well report any number, because it becomes meaningless, and once you undermine confidence in official statistics, especially from the MOHW, you might as well shut up shop and go home.
Now the positivity rate is also an interesting statistic in its own right. What does it actually tell us? At the most basic level, it simply tells us how many tests were positive as a percentage of the total number of tests. Why is this interesting, and how can we use it? Well, these are two excellent questions, and I’m not sure that it is useful at all, actually. The tests themselves are not randomly conducted across the country to lead us to any conclusions about how widespread COVID is in the community. If the majority of tests are from close contacts of people already confirmed as positive, it might give us information on how easily the virus spreads between people — but this is hugely dependent on how good the contact-tracing is at reaching those closest to the patient. If you have 1 person confirmed positive who lives with a large family at home, then you would expect more cases and a higher positivity rate than if it was a single person living on his/her own. So what exactly does the positivity rate mean? Well, beyond its basic definition, nothing as far as I can see.
So, in my opinion, whether tourists are included or not makes no difference. However, knowing if they are included makes a world of difference to the confidence we have in official data, and for transparency in general. And if they are, they should be marked separately so that if there are doubts about the data, you could show the rate, including tourist data and excluding tourist data to see if there is any marked difference.
The more you think about this data, the more questions you can pose. For instance, if tourist tests are included, what percentage of the total tests do they account for? If we do 1000 tests, and 900 were done on tourists leaving the country, then it would suggest that our community testing isn’t very widespread. We have to encourage, and gently force, MOHW to be open with all its data, and make the source data available for anyone to examine. They release data for males and females, for example, but not by age group — and we know age is a significant factor in COVID recoveries.