amenorrhea: Amenorrhea from clinical trial of contracepting women
In ALA: Data sets and examples for the book "Applied Longitudinal Analysis"

Description Usage Format Details Note Source References Examples

The data are from a longitudinal clinical trial of contracepting women.

1	data(amenorrhea)

A data frame with 4604 observations on the following 4 variables.

id: a factor with 1151 levels
dose: a factor with levels low and high
day: a numeric vector; days since initial injection
amenorrhea: a factor with levels no and yes

In this trial women received an injection of either 100 mg or 150 mg of depot-medroxyprogesterone acetate (DMPA) on the day of randomization and three additional injections at 90-day intervals. There was a final follow-up visit 90 days after the fourth injection, i.e., one year after the first injection. Throughout the study each woman completed a menstrual diary that recorded any vaginal bleeding pattern disturbances. The diary data were used to determine whether a women experienced amenorrhea, the absence of menstrual bleeding for a specified number of days. A total of 1151 women completed the menstrual diaries and the diary data were used to generate a binary sequence for each woman according to whether or not she had experienced amenorrhea in the four successive three month intervals. In clinical trials of modern hormonal contraceptives, pregnancy is exceedingly rare (and would be regarded as a failure of the contraceptive method), and is not the main outcome of interest in this study. Instead, the outcome of interest is a binary response indicating whether a woman experienced amenorrhea in the four successive three month intervals. A feature of this clinical trial is that there was substantial dropout. More than one third of the women dropped out before the completion of the trial.

Original variable names have been adapted to R conventions. Variable day was recoded from the original sequential number to the corresponding number of days since initial injection.

http://biosun1.harvard.edu/~fitzmaur/ala

Machin D, Farley T, Busca B, Campbell M, d'Arcangues C (1988) Assessing changes in vaginal bleeding patterns in contracepting women. Contraception 38:165-179.