Safer Solutions: What Is Relative Risk?

In an increasingly divided and polarized world, it can be hard not to think of everything as “good” or “bad,” “right” or “wrong,” and “moral” or “immoral.” Although it is easy to fall into this thought pattern, we are rarely able to achieve perfectly good behaviors or outcomes, especially when it comes to our health. That’s why it’s important to offer options that let people make gradual changes toward less risky behaviors rather than promoting an “all or nothing” mentality.

Not even Bryan Johnson, the tech entrepreneur on a quest to live “forever” (and the subject of a new documentary), makes perfect health choices or avoids all risks. If a tech billionaire with more resources at his disposal than most of us can imagine is unable to eliminate all health risks, we can’t expect regular people to do so. Instead, a “relative risk” mindset can empower us to make gradual, attainable changes to better our health.

In health research, relative risk has a very specific definition: a statistical measurement that compares the likelihood of an event happening between two groups who engage in different behaviors or are exposed to different treatments. While this is a useful way to quantify risk, there’s no need to be a math whiz to apply relative risk to day-to-day life.

From a harm reduction perspective, risk exists on a continuum. Think of how many shades of a color exist between its darkest and lightest tone. Similarly, there are many options between the most risky and least risky choices, including for substance use. Relative risk in harm reduction is about moving along the continuum from a more risky choice to a less risky one.

Relative risk is particularly relevant when it comes to tobacco use. Although the number of people who smoke has decreased significantly over time, smoking cigarettes is still a leading cause of preventable death in the United States. Relative risk was not highly relevant to smoking until products entered the market that allowed people to consume nicotine (the addictive but relatively low-risk chemical found in tobacco) without burning tobacco and inhaling the many cancer-causing chemicals contained in smoke. Products like electronic cigarettes and oral nicotine pouches or lozenges allow people who smoke to consume nicotine while decreasing their exposure to the chemicals that cause death and disease. So, relative to smoking, these products are lower risk.

Another example is opioid use during pregnancy. Using opioids during pregnancy can have a number of negative consequences for the fetus and the parent, up to and including death. However, pregnancy doesn’t magically make quitting opioids any easier. In fact, the American College of Obstetricians and Gynecologists recommends against medically supervised withdrawal (i.e., detoxification) during pregnancy because relapse rates are so high. This is important because relapse increases overdose risk due to decreased opioid tolerance and can increase the risk of obstetric complications or interrupt prenatal care.

That’s why medications for opioid use disorder (MOUD), such as methadone and buprenorphine, are recommended to treat opioid dependence during pregnancy. Using MOUD during pregnancy decreases the risk of death, including from overdose; improves pregnancy outcomes; and increases engagement with prenatal care. As with any medication, there are some health risks and implications for using MOUD during pregnancy. However, these outcomes are treatable and typically do not affect the long-term well-being of an infant or parent.

In other words, while MOUD use during pregnancy does have some risks, they are substantially lower than the risks associated with continuing opioid misuse or quitting opioids suddenly.

One might think, “Isn’t the safest option not to consume tobacco products or opioids at all?” This is absolutely true. However, completely stopping the use of an addictive substance is often very difficult, if not impossible. Much like how few people can completely eliminate sugar or processed food from their diets forever, it is more realistic to reduce the amount of these foods we eat. This is harm reduction in everyday life, and harm reduction for substance use follows the same logic. Risk is relative, and whether it’s eating fast food every day versus indulging once a week or smoking versus vaping, the goal of harm reduction is to move people down the risk continuum to less risky behaviors.

Approaching health with a relative risk mindset helps people adjust their behavior gradually, which can feel more attainable and reasonable than going from all to nothing. As we navigate a world that often asks us to pick from only two options, it would serve us well to remember that behavior and risk are more like a dial than a switch.