Graph description: Statistical methods for assessing agreement between two methods of clinical measurement, 5

This is a scatter diagram showing the difference between logarithm of velocity of circumferential fibre shortening (VCF) by the two modes, long minus short, on the vertical axis and the average of the log VCF measurements by the two modes on the horizontal axis. There is a suggestion of a relationship between the variables: the variability of the differences increases as VCF increases, but not so dramatically as in the previous graph, Figure 4. This is mainly produced by a few points with low average which are all close to the mean line. Three horizontal straight lines are shown, marked mean + 2SD, mean, and mean - 2SD. Five points are outside the outer lines, all towards the right hand side of the graph. The mean line is very close to zero.


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Last updated: 13 January, 2004.