Data on serum cholesterol from the National Cooperative Gallstone Study (NCGS).


Source: Table 2 (page 657) of Wei and Lachin (1984). 
Reproduced with permission of the American Statistical Association.

Reference: Wei, L.J. and Lachin, J.M. (1984). Two-Sample Asymptotically Distribution-Free 
Tests for Incomplete Multivariate Observations. Journal of the American Statistical Association, 79, 653-661.


Description:

The data are from the National Cooperative Gallstone Study
(NCGS), where one of the major interests was to study the safety 
of the drug chenodiol for the treatment of cholesterol gallstones
In this study, patients were randomly assigned to high-dose (750 mg per
day), low-dose (375 mg per day), or placebo. This dataset consists of
a subset of data on patients who had floating gallstones and who were
assigned to the high-dose and placebo groups.
In the NCGS it was suggested that chenodiol would dissolve gallstones 
but in doing so might increase levels of serum cholesterol. As a result, 
serum cholesterol (mg/dL) was measured at baseline and at 6, 12, 20, and 
24 months of follow-up. Many cholesterol measurements are missing because 
of missed visits, laboratory specimens were lost or inadequate, or 
patient follow-up was terminated.


Variable List:

Treatment Group (1=High dose chenodiol, 2-Placebo), Subject ID, 
Response at Baseline, Response at Month 6, Response at Month 12, 
Response at Month 20, Response at Month 24.

Note: Response = Serum cholesterol (. denotes missing value).