Noncommunicable diseases (NCDs), meaning heart disease, stroke, cancer, diabetes and chronic lung disease, cause 74 percent of all deaths worldwide, according to the World Health Organization. More than three-quarters of NCD deaths, and 86 percent of the 17 million premature deaths before age 70, occur in low- and middle-income countries. Those are national averages. On October 20, WHO published a 185-page report that looks inside them.

What WHO measured

The report, State of inequality: noncommunicable diseases and their risk factors, is described by WHO as the first comprehensive global assessment of within-country inequalities in these diseases. It examines four major NCDs (cancer, cardiovascular disease, diabetes and chronic respiratory disease) and five risk factors: alcohol use, obesity and unhealthy diet, insufficient physical activity, tobacco use and air pollution.

The team drew on nine multicountry data sources and analysed 35 indicators, broken down by up to eight dimensions of inequality, including sex, age, economic status, education and place of residence. An accompanying brief adds employment, disability and migration status.

Hosseinpoor, who leads WHO's Health Inequality Monitoring Team, said it is the first attempt to systematically measure NCD inequalities on a global scale, and that the findings show both which populations are being left behind and where a lack of data hides the picture.

Education and income decide who is diagnosed

The clearest pattern is a double disadvantage. Evidence from low- and middle-income countries shows that less educated populations tend to have higher rates of hypertension and diabetes, WHO said. At the same time, they are less likely to be diagnosed or screened. Across countries, poorer and less-educated women are less likely to receive cervical cancer screening, while tobacco use is higher among less educated men than among more educated men.

The people most exposed to risk are often the people least likely to be caught early, so the gap compounds from prevention through to treatment.

Where you live changes what hurts you

Geography cuts both ways. In many low- and middle-income countries, rural populations have less access than urban ones to hypertension diagnosis and treatment and to cervical cancer screening. Yet the pollution picture reverses depending on the setting: rural households may face greater exposure to household air pollution, while urban populations often face greater exposure to outdoor air pollution, according to the report.

A single national figure for air pollution exposure or hypertension control would therefore hide two different problems in two different places. A policy built around a clinic in a city would miss the villager whose main exposure is a smoky kitchen, and a rural programme would miss the city dweller breathing traffic fumes.

Sex, age and work

The patterns differ by gender and age, in ways that undermine tidy stereotypes. Men are more likely to use tobacco and alcohol and are less likely to be diagnosed and treated for hypertension. Women are less likely to be sufficiently physically active, while obesity is more common among women, particularly in low- and middle-income countries.

Age matters too. Younger adults with hypertension are less likely to be diagnosed and treated than older adults with the same condition. Insufficient physical activity tends to rise with age, and obesity is more common in people aged 40 to 70. The report also links unemployment to higher levels of physical inactivity, notes that people living with disabilities face greater barriers to prevention, screening and treatment, and says migrants may face financial, administrative or language barriers to care.

Obesity shows how the pattern plays out in practice. Our report on WHO's first global guidelines for child and adolescent obesity shows how much of the response rests on structured support that many families cannot easily reach, which is exactly the kind of gap this new report is trying to quantify.

The hole in the evidence

The most uncomfortable finding is about the data itself. The report identifies significant gaps in comparable, disaggregated data, WHO said, and Hosseinpoor flagged that a lack of inequality data hinders understanding in some areas. If a country does not collect NCD information by income, education or location, its policymakers cannot see who is missing out, and WHO cannot compare it with others.

That matters because the report's ambition is practical. WHO's accompanying advocacy brief sets out three priorities: scale up proven interventions that address NCD inequalities, use disaggregated data to direct policies and resources to the populations with the greatest need, and routinely measure inequalities to monitor progress. It also stresses delivering WHO's recommended "best buys," the cost-effective population-wide measures for NCD prevention, in ways that reach the groups facing the biggest barriers.

What to take from it

Labrique, who directs WHO's Data, Digital Health, Analytics and AI Department, called inequality data a tool for action, not just a record of differences. The point is fair, but it carries an obligation. A report like this is only useful if countries then collect the numbers, publish them and change where services go.

The test is whether governments that sign up to global NCD targets start reporting results by who benefits, not only by how many. Until then, an average improvement can sit alongside a worsening gap, and nobody will see it.

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