Chronic illness tracks with whether people vote — and the direction is not uniform

Who turns out to vote is not a random slice of the population, and health is one of the things that sorts it. The association runs in a direction people often assume is simple — sicker means less likely to vote — but the research is more interesting than that, because different conditions pull in different directions. Two studies, one American and one Finnish, make the point from opposite methodological ends.

The US survey

The first analysed whether a diagnosis with any of five chronic conditions — diabetes, cancer, heart disease, asthma, and arthritis — was associated with turnout in the 2012 US presidential election [s1]. It used cross-sectional survey data from 16 states in the 2013 and 2014 Behavioral Risk Factor Surveillance System, with voting measured by a survey item asking respondents whether they had voted [s1].

The headline result cuts against the simple story: individuals diagnosed with diabetes were 7 percentage points more likely to vote than those without the diagnosis [s1]. The relationship was particularly strong among respondents who identified as Hispanic or multiracial [s1]. At the same time, and consistent with earlier work, lower self-rated health was associated with lower odds of turning out [s1].

So health does not map onto turnout along a single axis. A general sense of being unwell depresses participation, while a specific, managed, clinically engaged condition like diabetes can coincide with more of it.

The Finnish register

The second study comes at the question with a very different tool: administrative records rather than a survey [s2]. It used an individual-level register covering an 11% random sample of the entire electorate in the 1999 Finnish parliamentary elections, linking turnout to hospital discharge diagnoses and reimbursed prescriptions to identify people with chronic, hospital-treated disease [s2].

After adjusting for gender, age, education, occupational class, income, partnership status, cohabitation with children, and hospitalisation on election day, the conditions spread across a wide range [s2]. Neurodegenerative brain disease had the strongest negative relationship with voting — dementia carried an odds ratio of 0.20 (95% CI 0.18 to 0.22), meaning people with dementia were far less likely to vote [s2]. Alcoholism (OR 0.66) and mental disorders also pointed downward, with depression at 0.91 and psychotic mental disease at 0.79 [s2]. Cancer and chronic obstructive pulmonary disease or asthma, by contrast, had a slight positive association, both at an odds ratio of 1.05 [s2]. Having more than one condition at once further lowered the probability of voting [s2].

A register study avoids one weakness of the survey: nobody has to remember or report whether they voted, because the turnout record is official. That the two designs, in two countries, two decades and two electoral systems apart, both find health sorting turnout — and both find the sorting is condition-specific rather than uniform — is more persuasive than either alone.

What this can and cannot support

Both are observational, and the limits are real.

Neither can establish that illness causes a change in voting. The arrows could run the other way, or a third factor could drive both. People who manage a condition like diabetes are in regular contact with the health system, which may raise civic engagement for reasons that have nothing to do with the disease itself. Dementia's strong negative association is partly mechanical — advanced cognitive impairment directly impedes the act of voting — and partly about the barriers facing people who need assistance to cast a ballot.

The measures differ, too. The US study leans on self-reported turnout, which people over-report, and on a survey diagnosis. The Finnish study captures only hospital-treated disease, so milder cases managed entirely in primary care are invisible to it. The conditions are not defined identically, and the elections are of different kinds.

Why it matters on an election day

The point is not that any illness should change how a person votes, or which way. It is that if turnout is patterned by health, then the preferences of the sickest — and of people with conditions that make the mechanics of voting harder — are systematically under-weighted in what gets counted. That is a question about access and representation, not about any candidate.

It also reframes a familiar public health idea. Political participation is sometimes treated as an upstream determinant of health, on the logic that groups who vote get policies more responsive to their needs. These studies show the relationship also runs the other way: health shapes who participates in the first place. Both can be true at once, and together they describe a loop worth watching.

This article is informational and does not constitute medical or civic advice.