The 'amenorrhea' dataset pertains to a longitudinal clinical trial of contracepting women comparing the effectiveness of two dosages (100mg or 150mg) of depot-medroxyprogesterone acetate (DMPA) (Machin et al., 1988), an injectable contraceptive. A total of N=1151 women kept a menstrual diary according to whetherthey had experienced amenorrhea in foursuccessive three-month intervals(binary outcome). This clinical trial had a substantial dropout. The "amenorrhea" dataset has information on the following variables:

Name Description

id - Person ID

dose - Treatment group ( 0=Low (100mg), 1=High (150mg) )

time - 1,2,3, or 4, for the four consecutive 3-month injection intervals

status - 0=No amenorrhea , 1=amenorrhea

A marginal model was fitted for this data with a binary outcome. Given the output below, interpret all coefficients (time, time2, dosehigh, time:dosehigh, time2:dosehigh) for the marginal model. Provide descriptive interpretations for each.

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