Thinking about risk
We live in a world full of hazards. A hazard is anything that has the potential to harm or kill us. Tall ladders, sharp knives, hornet nests – all are hazards. Risk = Hazard + Exposure. When we climb a tall ladder, whittle with a sharp knife, or knock down a hornet nest, they become risks. When we encounter or use something dangerous, there’s a chance that it will harm us. The simplest everyday tasks, from changing a light bulb to peeling an apple, involve some level of risk.
Avoiding a hazard completely reduces the risk to zero. For example, skydiving is a surprisingly safe sport–less than 1 fatality per 100,000 jumps in each of the past dozen years. However, low risk doesn’t mean no risk. The only way to make skydiving zero risk is to forego the activity completely, an easy decision for most of us to make! But it’s impossible to consider the risk of each of the dozens of things we do every day. We would have time for nothing else!
When it comes to hazards that threaten our health or family members’ wellbeing, it’s a different story. The stakes are too high take chances.
Each of us has a certain risk of developing various diseases such as heart disease, cancer, or COVID. Medical scientists analyze case rates over time to determine these risks, which they use to evaluate the performance of new treatments and public health measures. If one in ten people develops heart disease, the absolute risk of getting heart disease is 10%. Relative risk, on the other hand, describes the differences between groups. Smokers, for example, have a greater risk for heart disease than nonsmokers.
Treatment results are also described in terms of relative risk. If 20% of cancer patients die with treatment A and 15% die with treatment B, the relative risk reduction with treatment B is 25%. However, the absolute risk reduction is 5%, the difference between the two rates. It is important to distinguish between absolute and relative risks when reading news reports, which may not say explicitly which they mean.
When we chose to call our group Let’s end COVID! we believed – or at least hoped – that the country would reach herd immunity and the virus would die out for lack of new hosts.
Unfortunately, that didn’t happen, and for several reasons it probably never will. It’s easy to blame vaccination reluctance, which absolutely has played a role, but other reasons are also key: certain people cannot be vaccinated, vaccines work well but don’t stop all transmission, immunity from both vaccination and previous infection wanes over time, and new variants are transmitted much more easily. Delta was more transmissible than original SARS-CoV-2 and Omicron is more than three times as infectious as Delta.
We yearn for this pandemic to be over. It isn’t. As a recent writer in this space said, we may be done with COVID, but COVID is not done with us.
Pandemics end when the number and rate of new infections drop enough that society is no longer disrupted or the healthcare system overwhelmed. “Endemic” diseases are always present but spread at predictable rates at levels communities can manage effectively with vaccines and other measures. Flu has been endemic for a century and is still dangerous, especially to older adults and others with inadequate immune systems. We are used to having it around, even though 9 to 41 million Americans get it each year, hundreds of thousands are hospitalized, and 12,000 to 51,000 of them die.
COVID-19 is still a pandemic. Infection rates and deaths remain high around the world, and because the virus mutates so rapidly into more infectious versions that may evade existing vaccines and treatments, it is not reliably predictable or manageable. Thanks to the effective vaccines and treatments developed since this pandemic began, severe cases and deaths have dropped a lot, but COVID is still killing more people than the flu.
We are going to have to live with COVID-19 for a while, maybe for a long while, no matter how we wish it were otherwise.
It’s natural to feel that we should be free to make the best choices we can for ourselves and our families. Getting COVID is the surest way to lose that freedom. The best way to keep it is to protect ourselves by getting vaccinated, by getting recommended boosters to keep immunity high, by testing when we have symptoms, by watching our community levels at https://www.cdc.gov/coronavirus/2019-ncov/index.html, and by doing the simple things we know help keep us safe where levels are high: avoiding indoor crowds, wearing high quality masks, handwashing, and social distancing. The risks for severe disease or death, and for devastating long COVID even after mild infections, are too high to leave to chance.
Michael Heyd, a retired medical librarian from Fairfield Township who spent more than forty years searching the literature for professional hospital staff, is a member of Let’s end COVID!, a group of concerned people in Northcentral PA working to overcome the COVID-19 pandemic through education, outreach and mitigation.