The study of the relationship between risk factors and outcomes is important both in etiological and prognostic research. To assess the strength of a given risk factor-outcome relationship we use measures that are calculated in relative and absolute terms. Risk ratio, incidence rate ratio and odds ratio are relative measures of this relationship. Risk difference (or attributable risk) and rate difference (or attributable rate) are absolute measures of the same relationship. Risk difference and rate difference are calculated by subtracting the risk and the incidence rate in exposed individuals from that in unexposed individuals, respectively. The choice of these measures depends on the study aim. Relative measures are commonly used in etiological studies while absolute measures are mainly used in public health research.

1.
Noordzij M, Dekker FW, Zoccali C, Jager KJ: Measures of disease frequency: prevalence and incidence. Nephron Clin Pract 2010; 115:c17–c20.
2.
Zoccali C, Mallamaci F, Parlongo S, et al: Plasma norepinephrine predicts survival and incident cardiovascular events in patients with end-stage renal disease. Circulation 2002;105:1354–1359.
3.
Fellström B, Jardine A, Schmieder RE, et al: Rosuvastatin and cardiovascular events in patients undergoing hemodialysis. N Engl J Med 2009;360:1395–1407.
4.
Selvin S: Statistical Analysis of Epidemiologic Data. New York, Oxford University Press, 1991, p 452.
5.
Matteucci MC, Wuhl E, Picca S, et al: Left ventricular geometry in children with mild to moderate chronic renal insufficiency. J Am Soc Nephrol 2006;17:218–226.
6.
Dixon BS, Beck GJ, Vazquez MA, et al: Effect of dipyridamole plus aspirin on hemodialysis graft patency. N Engl J Med 2009;360:2191–2201.
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.