Hospital-based stroke diagnoses among the oldest old in the United States: 1997 to 2006.

BACKGROUND AND PURPOSE Continued surveillance of stroke trends among the very elderly is needed to determine how best to mitigate the likely rise with time in the proportion of strokes in this relatively understudied age group. This study assessed recent time trends in the proportion of hospitalized patients with stroke who are very elderly. METHODS Data were obtained from all US states that contributed to the Nationwide Inpatient Sample. Patients with stroke diagnoses were identified by the International Classification of Diseases, 9th Revision procedure codes. Percentage of stroke diagnoses among persons aged >or=80 years was evaluated. RESULTS Between 1997 and 2006, the absolute number of US hospital-based stroke diagnoses lessened (from 680 666 to 609 381). Of all patients with stroke, very elderly men constituted 25.2% in 1997 versus 25.1% in 2006 (P=0.83), whereas very elderly women were 39.5% in 1997 versus 39.9% in 2006 (P=0.55). Very elderly persons comprised similar percentages of primary acute ischemic stroke in 1997 versus 2006, but their proportion of primary acute intracerebral hemorrhages rose from 29.4% in 1997 to 32.2% in 2006 (P=0.005) and of primary acute subarachnoid hemorrhages from 12.5% in 1997 to 14.5% in 2006 (P=0.039). CONCLUSIONS Across the last decade, the overall percentage of persons in the United States hospitalized with stroke, who were very elderly, remained unchanged, but the proportion of persons with primary acute hemorrhagic strokes who were very elderly increased.