Prevalence of stroke and stroke-related disability. Estimates from the Auckland stroke studies

Abstract

Background and purpose: To provide estimates of the prevalence of stroke and stroke-related disability for international comparisons and for planning purposes.

Methods: Estimates of prevalence were derived from two population-based studies conducted 10 years apart in Auckland, New Zealand. The first, carried out in 1981, included information on survival and stroke-related disability to 14 years after stroke, and the second, undertaken in 1991 to 1992, included this information up to 3 years after stroke. An actuarial model was developed that took into account changes in incidence, long-term survival, and population structure.

Results: Overall, it was estimated that 7491 people (3793 men and 3698 women) living in Auckland (total population 945,000) in 1991 had experienced a stroke at some stage in the past. This represents an age-standardized rate of 833 per 100,000 (991 per 100,000 in men and 706 per 100,000 in women) in the population aged 15 years and older. When only those who have made an incomplete recovery are considered, prevalence falls to 461 per 100,000. Of this group, one third (173 per 100,000 population 15 years and older) required assistance in at least one self-care activity.

Conclusions: Usual estimates of stroke prevalence, which include all people who have ever experienced a stroke, may overestimate by almost twofold the prevalence of stroke-related disability, since many have either recovered or have no continuing dependency related to stroke. Overall prevalence does not provide information with sufficient precision for planning and purchasing ongoing services for stroke patients.