Stroke in an elderly population: incidence and impact on survival and daily function. The Italian Longitudinal Study on Aging.

BACKGROUND

Epidemiological data are essential to estimate the burden of stroke. We evaluated stroke incidence in older Italians and the effect of first-ever stroke on survival and activities of daily living (ADL).

METHODS

The analysis was performed in the Italian Longitudinal Study on Aging (ILSA) sample, consisting of 5,632 individuals aged 65-84. The ILSA aims at major cardiovascular and neurological age-associated diseases. The baseline survey was performed in 1992 to detect prevalent diseases. The longitudinal examination started on September 1995 aiming at incidence, function and survival.

RESULTS

Complete follow-up data were achieved for 77% of the baseline stroke-free cohort (4,164 persons; 50.9% males; mean age 74.5 +/- 5.7 years). Incidence for first-ever stroke was 9.51 (95% CI: 7.75-11.27) per 1,000 person years and 12.99 (95% CI: 10.99-14.98) including recurrent stroke (total incidence). Crude mortality was 49.2% among first stroke patients and 15% among persons without stroke. The first-ever stroke mortality risk ratio, adjusted for demographics and comorbidity, was 2.40 (95% CI: 1.62-3.54). In survivors, impairment of at least one ADL was present in 67.6% of first-ever stroke patients vs. 31.6% of individuals without stroke. The comorbidity-adjusted OR was 2.63 (95% CI: 1.20-5.78) in the total cohort, and 4.00 (95% CI: 1.39-11.46) in individuals without disability at baseline.

CONCLUSIONS

The ILSA provides the first data on stroke incidence in Italy on a national basis. Overall, 153,000 new cases can be expected annually in the Italian elderly population. First-ever stroke still has a strong effect on survival and function of older persons.