Incidence and occurrence of total (first-ever and recurrent) stroke

Background and Purpose-It has recently been hypothesized that the figure of approximately half a million strokes substantially underestimates the actu al annual stroke burden for the United States. The majority of previously r eported study was designed to estimate the occurrence, incidence, and chara cteristics of total (first-ever and recurrent) stroke by using a large admi nistrative claims database representative of all 1995 US inpatient discharg es. Methods-We used the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project, release 4, which contains approximate to 20% of all 19 95 US inpatient discharges. Because the accuracy of International Classific ation of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) coding is suboptimal, we performed a literature review of ICD-9-CM 430 to 438 valida tion studies. The pooled results from the literature review were used to ma ke appropriate adjustments in the analysis to correct for some of the inacc uracies of the diagnostic codes. Results-There were 682 000 occurrences of stroke with hospitalization (95% CI 660 000 to 704 000) and an estimated 68 000 occurrences of stroke withou t hospitalization. The overall incidence rate for occurrence of total strok e (first-ever and recurrent) was 259 per 100 000 population (age- and sex-a djusted to 1995 US population). Incidence rates increased exponentially wit h age and were consistently higher for males than for females. Conclusions-We conservatively estimate that there were 750 000 first-ever o r recurrent strokes in the United States during 1995, This new figure empha sizes the importance of preventive measures for a disease that has identifi able and modifiable risk factors and for the development of new and improve d treatment strategies and infrastructures that can reduce the consequences of stroke.