Stroke incidence in adults under 55 nearly doubled over three decades in a US population study

Design

Population-based incidence and case-fatality study, six periods from 1993/4 to 2020

Population

2,076 first-ever strokes in adults aged 20 to 54 in a five-county US region

Primary outcome

Stroke incidence and 30-day case fatality over time

Effect

Incidence 33.90 to 62.18 per 100,000 person-years (trend p = 0.04); 30-day case fatality 11.7% to 9.4%

This population-based study ascertained and adjudicated hospitalised strokes in a five-county US region across six study periods between 1993/4 and 2020. It identified 2,076 first-ever strokes in people aged 20 to 54.

Incidence in young adults rose from 33.90 to 62.18 per 100,000 person-years (trend p = 0.04), while falling in older adults from 618.78 to 453.04. The rise appeared to be driven by ischaemic stroke, which went from 23.8 to 47.3 per 100,000 person-years. Hypertension, diabetes, atrial fibrillation and substance use became more common over time. The 30-day case fatality in young adults eased from 11.7% to 9.4%, with the decline led by intracerebral and subarachnoid haemorrhage.

The data are from one US region and the study cannot say which risk factor drove the trend. Local data for India differ, but the direction raises the same questions for clinicians who see young stroke.

• Look for hypertension, diabetes, atrial fibrillation and substance use in every young patient with stroke.
• Ask about substance use directly; it became more common over the study period.
• Do not assume a young patient with ischaemic stroke has an unusual cause before checking common vascular risk factors.
• Thirty-day case fatality in young adults eased from 11.7% to 9.4% over the same period.

Why it matters

It challenges the idea that falling overall stroke rates mean stroke is receding as a problem in younger people.

Don't overread it

This is a descriptive study from one US region; it cannot attribute the rise to any single risk factor, and incidence in India may differ.

The statistics, in plain English

A trend p-value of 0.04 for the young adult rise means the upward slope is unlikely to be chance, but with only six time points the trend estimate is imprecise.

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