Tiny Tim is not the main character of A Christmas Carol. That would be Ebenezer Scrooge, the old miser who, through the intercession of three spirits, changes, by the end of Charles Dickens’ classic tale, into a good man. It is hard to read A Christmas Carol, however, or watch one of its many film adaptations, and not feel Tiny Tim is somehow its heart. Born sickly, into a family without the means to properly care for him, he seems fated for an early death, until Scrooge’s reformation, when the old man decides to help the boy, becoming a “second father” to him, and providing the financial support that ensures Tiny Tim will live.

Dickens announces this uplifting development in the story’s closing lines; it is the tale’s emotional payoff, the final indicator that the battle for Scrooge’s soul has been won by his better angels, that the bitter man he once was is no more. By caring for Tiny Tim, Scrooge at last comes into his own as a fully human being.

Imagine, now, a version of A Christmas Carol where, despite Scrooge’s change of heart, Tiny Tim still dies. This would hardly be a happy ending. Tiny Tim is in many ways a stand-in for the most vulnerable members of Scrooge’s society, those who did not share in the economic gains or improved living standards created by the Industrial Revolution. Concluding the tale with the death of such a figure would have cast a pall over the entire piece. Dickens knew that people, and stories, are judged by their treatment of the disadvantaged—those who lack resources to live healthy lives. For Scrooge, and the world he inhabits, to be truly redeemable, Tiny Tim has to live.

But A Christmas Carol is fiction. In our own world, the vulnerable and the marginalized too-often lack the chance to live long, healthy lives, and few have wealthy benefactors to swoop in and save the day. For these people, health remains nearly as out of reach as it was for Tiny Tim.

In the US, people with a college degree, for example, can expect to live a decade longer than people who never complete high school. The life expectancy of black Americans is about three-and-a-half years lower than that of white Americans; black Americans are also ten times likelier to die from gun homicide. LGBT youth are two-to-three times likelier than the general population to attempt suicide. Transgender individuals are 49 times likelier to have HIV. And, as I wrote in my last column, people who live in economically advantaged areas are often significantly healthier than those who do not, even when the two areas are relatively close together. The geographic divide between the healthy and the sick is well captured by the twenty year gap in life expectancy between US counties with the highest life expectancy and those with the lowest.

These statistics are sobering, but how much do they really matter? In the last one hundred years, US life expectancy rose from about 47 years to about 79 years. This is in large part for the same reason life improved for many during the Industrial Revolution, when better living standards created by large-scale socioeconomic forces gave more people access to the material resources—nutritious food, for example, and better hygiene—that create health. Given this tremendous overall progress, should we really trouble ourselves over the risks run by a comparative few?

Last month, the National Center for Health Statistics provided a compelling answer to that question. It reported that US life expectancy has declined for the third consecutive year, dropping between 2016 and 2017 from 78.7 to 78.6. The US last saw such a decline around 1918, after a Spanish flu pandemic infected an estimated third of the global population, killing about 675,000 Americans. There are two key reasons why our current life expectancy resembles that of a society in the grip of a pandemic.

The first is opioids. There were 70,237 drug overdose deaths in the US in 2017. 47,600 involved an opioid. The second is suicide, especially suicide by gun. There were 47,000 suicides in the US in 2017, about 22,000 of which were firearm suicides. Taken together, these modern epidemics threaten the life expectancy gains of the last century. Yet before these crises emerged as clear threats to the health of the many, they threatened the health of the marginalized few. Addiction, for example, is something we have long refused to fully reckon with, because we have insisted on characterizing it as a problem solely for people who are not us.

We decided it is an issue for “the addict,” someone who exists on the fringes of society, living in squalor, with only her bad choices to blame for her suffering. By scapegoating people with addiction, we managed, for years, to ignore the true causes of this epidemic. They include the overprescribing of pain medication, an abundance of cheap heroin, the rise of synthetic opioids like fentanyl, and the socioeconomic deprivation that has led to a crisis of despair in American communities, driving many people to the false comfort of drugs.

None of these causes have anything to do with personal choice. They are all macro-level forces, shaped by political incentives, industrial practices, and even, in the case of the overseas fentanyl black market, international trade policy. Solving the addiction crisis means addressing it at the level of these conditions, not blaming the victims of powerful upstream forces.

When we dismiss the few, when we ignore their poor health, we also ignore the social, economic, and political context that makes them sick. By turning a blind eye to these conditions, we allow them to worsen, until they no longer threaten only the few, they threaten everyone. The opioid crisis was never just a problem for “addicts,” but we were once able to convince ourselves it was. We were able to look at people who would seemingly rather die than live without drugs, and say, quoting Scrooge, “If they would rather die, they had better do it, and decrease the surplus population.”

Now the crisis has reached a point where we can no longer deny that no one is immune from the danger of addiction. Similarly, we may have once thought guns were just a problem for criminals or people living in violent neighborhoods. For decades, this led us to accept a status quo that blocked, at every turn, commonsense gun safety legislation. Because of this, the danger of guns is now in our schools, at our music festivals, in our homes, and in our moments of despair. The problems of the few are now the problems of the many.

It is strange that we have allowed something we cannot bear to see in A Christmas Carol—the preventable suffering and needless death of vulnerable people—to become a defining feature of the real world. But we have. For decades, we let marginalized groups stay unhealthy, until their reality at last became our own. But this need not be our future. Like Scrooge, we have a chance to change course. We can do this by placing the marginalized few at the center of our conversation about health, and by improving the conditions that shape their lives. By creating a world where they can live healthy, we create a world where everyone can.

Sandro Galea, MD, DrPH, is Professor and Dean at the Boston University School of Public Health. His latest book, Well: What we need to talk about when we talk about health, will be published in May 2019. Follow him on Twitter: @sandrogalea