Graph description: Figure 15. Mean PEF after 6 months against baseline PEF for intervention and control asthmatic patients, with fitted analysis of covariance lines (data of Levy et al., 2000)

This is a scatter diagram.

The horizontal axis shows Baseline mean peak expiratory flow in litres per minute and is numbered 0, 200, 400, 600, 800. The vertical axis shows Mean peak expiratory flow after six months in litres per minute and is numbered 0, 200, 400, 600, 800.

There are two closely overlapping clouds of points labeled Intervention and Control. They lie closely around two rising parallel straight lines, the line for invention being just above that for control, by about 20 litres per minute. The points for Intervention appear to be very slightly higher than those for control.

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This page maintained by Martin Bland.
Last updated 11 August 2008.