Stroke prevalence surveys are more and more needed for health care and facility planning. Prevalence estimates and costs of the definition procedure may vary depending on different screening strategies. We evaluated the impact of these different strategies on the overall diagnostic procedure and on stroke prevalence estimates in the Italian Longitudinal Study on Aging. A population sample of 5,632 individuals aged 65–84 years was screened for stroke by a simple question on previous stroke diagnosis, questions on possible stroke symptoms and a simple neurological examination. Those screened positive by any of these procedures were fully examined by a neurologist for conclusive diagnosis. We determined the positive predictive value of each procedure on the final stroke diagnosis and calculated prevalence as if each procedure had been used separately. Using the three procedures combined, the prevalence rate was 6.0% (95% confidence interval, 5.4–6.7%). If each procedure had been used as the unique screening tool, the rates would have been 5.1% (4.5–5.7%), 4.1% (3.6–4.7%) and 2.3% (1.9–2.7%), and positive predictive values 66.4, 55.2 and 45.1%, respectively. Different screening procedures can affect stroke prevalence estimates. Compared to more complex screening strategies, the use of a simple question about previous diagnosis as the unique screening tool leads to only a slight underestimation of stroke prevalence and avoids a 66% increase in the number of subjects to be examined in a second-level specialist evaluation, potentially reducing the costs of the overall diagnostic procedure.

1.
Baum HM, Robins M: The National Survey on Stroke: Survival and prevalence. Stroke 1981;12(suppl 1):I59–I68.
2.
Kurtzke JF: The current neurologic burden of illness and injury in the United States. Neurology 1982;32:1207–1214.
3.
Sørensen PS, Boysen G, Jensen G, Schnohr P: Prevalence of stroke in a district of Copenhagen: The Copenhagen City Heart Study. Acta Neurol Scand 1982;66:68–81.
4.
Li SC, Schoenberg BS, Wang CC, Cheng XM, Bolis CL, Wang KJ: Cerebrovascular disease in the People’s Republic of China: Epidemiologic and clinical features. Neurology 1985;35:1708–1713.
5.
Aho K, Reunanen A, Aromaa A, Knekt P, Maatela J: Prevalence of stroke in Finland. Stroke 1986;17:681–686.
6.
Bharucha NE, Bharucha EP, Bharucha AE, Bhise AV, Schoenberg BS: Prevalence of stroke in the Parsi Community of Bombay. Stroke 1988;19:60–62.
7.
Paschalis C, Polychronopoulos P, Makris N, Kondakis X, Papapetropoulos T: Prevalence rate of cerebrovascular disease in the rural population of Northwest Peloponnese, Greece. Eur Neurol 1989;29:186–188.
8.
Mrabet A, Attia-Romdhane N, Ben Hamida M, Gharbi N, Le Noan H, Hentati R, Ben Mansour J, Srairi I: Aspects épidémiologiques des accidents vasculaires cérébraux en Tunisie. Rev Neurol 1990;146:297–301.
9.
Serradj Jaillard A, Hommel M, Mazetti P: Prevalence of stroke at high altitude (3,380 m) in Cuzco, a town of Peru: A population-based study. Stroke 1995;26:562–568.
10.
Bonita R, Solomon N, Broad JB: Prevalence of stroke and stroke-related disability: Estimates from the Auckland Stroke Studies. Stroke 1997;28:1898–1902.
11.
Hu HH, Chu FL, Chiang BN, Lan CF, Sheng WY, Lo YK, Wong WJ, Luk YO: Prevalence of stroke in Taiwan. Stroke 1989;20:858–863.
12.
Schoenberg BS, Anderson DW, Haerer AF: Racial differentials in the prevalence of stroke: Copiah County, Mississippi. Arch Neurol 1986;43:565–568.
13.
Mittelmark MB, Psaty BM, Rautaharju PM, Fried LP, Borhani NO, Tracy RP, Gardin JM, O’Leary DH: Prevalence of cardiovascular diseases among older adults: The Cardiovascular Health Study. Am J Epidemiol 1993;137:311–317.
14.
Bots ML, Looman SJ, Koudstaal PJ, Hofman A, Hoes AW, Grobbee DE: Prevalence of stroke in the general population: The Rotterdam Study. Stroke 1996;27:1499–1501.
15.
Reggio A, Rocca WA, Patti F, Grigoletto F, Meneghini F, Morgante L, Savettieri G, Salemi G, Cappello S, Di Perri R, for the Sicilian Neuroepidemiologic Study (SNES) Group: Prevalence of stroke: A door-to-door survey in three Sicilian municipalities. Neuroepidemiology 1996;15:92–102.
16.
Urakami K, Igo M, Takahashi K: An epidemiologic study of cerebrovascular disease in Western Japan: With special reference to transient ischemic attacks. Stroke 1987;18:396–401.
17.
Guccione AA, Felson DT, Anderson JJ, Anthony JM, Zhang Y, Wilson PW, Kelly-Hayes M, Wolf PA, Kreger BE, Kannel WB: The effects of specific medical conditions on the functional limitations of elders in the Framingham Study. Am J Public Health 1994;84:351–358.
18.
Maggi S, Zucchetto M, Grigoletto F, Baldereschi M, Candelise L, Scarpini E, Scarlato G, Amaducci L, for the ILSA Group: The Italian Longitudinal Study on Aging (ILSA): Design and methods. Aging Clin Exp Res 1994;6:464–473.
19.
Hatano S: Experience from a multicentre stroke register: A preliminary report. Bull WHO 1976;54:541–553.
20.
Kish L: Weighting for unequal Pi. J Off Stat 1992;10:183–200.
21.
SAS Institute: SAS, Version 6.08. Cary, SAS Institute, 1989.
22.
O’Mahony PG, Dobson R, Rodgers H, James OFW, Thomson RG: Validation of a population screening questionnaire to assess prevalence of stroke. Stroke 1995;26:1334–1337.
23.
Psaty BM, Kuller LH, Bild D, Burke GL, Kittner SJ, Mittelmark M, Price TR, Rautaharju PM, Robbins J: Methods of assessing prevalent cardiovascular disease in the Cardiovascular Health Study. Ann Epidemiol 1995;5:270–277.
24.
Hoeymans N, Feskens EJ, Van Den Bos GA, Kromhout D: Non-response bias in a study of cardiovascular diseases, functional status and self-rated health among elderly men. Age Ageing 1998;27:35–40.
25.
Wyller TB, Ranhoff AH, Bautz-Holter E: Validity of questionnaire information from old people on previous cerebral stroke. Cerebrovasc Dis 1994;4:57–58.
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.