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msm (version 0.4.1)

aneur: Aortic aneurysm progression data

Description

This dataset contains a list of transitions between grades of aortic aneurysms, measured by ultrasound examination of the diameter of the aorta.

Usage

data(aneur)

Arguments

format

A data frame containing 2662 rows. Columns correspond to 'starting state', 'end state', 'time interval', 'age at beginning of interval'. The stages represent successive degrees of aneurysm severity.

rll{ Stage 1 Aneurysm-free < 30 cm Stage 2 Mild aneurysm 30-44 cm Stage 3 Moderate aneurysm 45-54 cm Stage 4 Severe aneurysm > 55 cm } These were obtained from 4337 ultrasound scans from 838 men over 65. 683 of these men were aneurysm-free at age 65 and were re-screened every two years. The remaining men were aneurysmal at entry and had successive screens with frequency depending on the stage of the aneurysm. Stage 4 aneurysms are repaired by surgery.

source

The Chichester, U.K. randomised controlled trial of screening for abdominal aortic aneurysms by ultrasonography.

References

Couto, E. and Duffy, S. W. and Ashton, H. A. and Walker, N. M. and Myles, J. P. and Scott, R. A. P. and Thompson, S. G. (2002) Probabilities of progression of aortic aneurysms: estimates and implications for screening policy Journal of Medical Screening 9(1):40--42