Stroke risk doubles as wealth decreases

Medical Tribune June 2008 P12

David Brill

Low wealth and income are independent risk factors for stroke among those aged 50 to 64, according to new research.

The study, which comprised 19,565 participants from the US, is the first of its kind to distinguish wealth from income and education – factors that have traditionally been used to assess socioeconomic status.

The researchers found that the least-wealthy participants in this age group were more than twice as likely to have a stroke than their wealthier counterparts, following adjustment for other socioeconomic factors (hazard ratio 2.3, 95 percent confidence interval 1.6 – 3.4).

When comparing low income to high income subjects the adjusted hazard ratio for stroke was 1.8 (95 percent confidence interval1.3 – 2.6). The association with education was not significant following adjustment.

“Lack of material resources themselves, and particularly wealth, appear to strongly influence people’s chances to have a first stroke,” said lead author Dr. Mauricio Avendano, from the Erasmus Medical Centre in
Rotterdam, the Netherlands.

Neither wealth nor income, however, was associated with stroke in those aged over 65 – a finding that surprised the study authors.

“We expected wealth to be a strong predictor of stroke in the elderly,” said Avendano, who suggested that this observation could reflect a selective survival mechanism: if low-wealth individuals tend to die younger, then a sample of those who survive into old age will comprise a healthier selection of individuals.

Wealth was assessed by adding all housing and financial assets and subtracting the liabilities. This method provides a better overall reflection of economic resources than simply measuring income, the authors wrote in the journal Stroke. [2008 May;39(5):1533-40]

Participants were followed up for an average of 8.5 years. A total of 1,542 incidences of stroke were recorded during the study period.

Dr. Ho King Hee, a consultant neurologist at Gleneagles Medical Centre, Singapore, suggested that differing accessibility to good healthcare is the most likely explanation for wealth-related disparities in stroke risk.

He added that although the study was of some interest, the findings were likely to have little impact on the day-to-day diagnosis and assessment of stroke patients.

“Wealth, like age, is a non-modifiable risk factor. I wouldn’t be telling the patient to get richer to reduce his stroke risk,” said Ho.

“The classical modifiable risk factors for stroke (hypertension, diabetes, heart disease, carotid artery disease and raised cholesterol) are vastly more important in real-world terms. The important thing would be to provide cost-effective access to health care and not to be unduly concerned with something that is not really modifiable by either patient or doctor,” he said.