Is the pharmacological treatment of mild to moderate hypertension cost effective in stroke prevention?

Pooled data from clinical trials show that the incidence of fatal and nonfatal strokes combined is reduced by approximately 39% (95% CI: -48% to -28%) with antihypertensive treatment. However, given the relatively low incidence of stroke, it can be calculated that about 530 to 1375 mild to moderate hypertensive patients would need to be treated per year to prevent one stroke. Applying these results to the health service costs, both public and private, of treating mild to moderate hypertension in New Zealand we have estimated that the cost of preventing one stroke in those aged 35-64 years at between $110,900 and $285,400 in 1982 dollars. The offsetting hospital and community care costs to the health services of treating a stroke, was approximately $6500 giving a net cost of between $104,000 and $279,000 per stroke prevented. The cost of preventing a death from stroke was estimated to be between $356,000 and $1,822,000. Per year of life saved, this appears to be well in excess of such costly interventions as coronary artery bypass, heart transplantation and renal dialysis. Greater use should be made of inexpensive diuretics and nonpharmacological methods for the management of hypertension. A population strategy, rather than the present expensive high risk approach, could be far more cost effective in stroke prevention.