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Assessing seasonality in clinical research

  • Ton J. Cleophas EMAIL logo and Aeilko H. Zwinderman
Published/Copyright: July 7, 2012

Abstract

Background: Seasonal patterns are assumed in many fields of medicine. However, biological processes are full of variations and the possibility of chance findings can often not be ruled out.

Methods: Using simulated data we assess whether autocorrelation is helpful to minimize chance findings and test to support the presence of seasonality.

Results: Autocorrelation required to cut time curves into pieces. These pieces were compared with one another using linear regression analysis. Four examples with imperfect data are given. In spite of substantial differences in the data between the first and second year of observation, and in spite of otherwise inconsistent patterns, significant positive autocorrelations were constantly demonstrated with correlation coefficients around 0.40 (SE 0.14).

Conclusions: Our data suggest that autocorrelation is helpful to support the presence of seasonality of disease, and that it does so even with imperfect data.


Corresponding author: Ton J. Cleophas, Department of Medicine, Albert Schweitzer Hospital, Box 400, 3300 AK Dordrecht, The Netherlands

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Received: 2012-05-10
Accepted: 2012-06-08
Published Online: 2012-07-07
Published in Print: 2012-12-01

©2012 by Walter de Gruyter Berlin Boston

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