Table 1.

Low-Dose Aspirin and Risk of Anovulation in the EAGeR Trial (United States, 2007 to 2011): Key Features of the Data and Analysis

Data	Analysis
Clustered outcome data
—1 to 6 outcomes per woman based on menstrual cycles contributed to follow-up	Accounted for within-woman correlated outcomes with generalized estimating equations extension of the log-binomial regression model
—Number of menstrual cycles contributed was associated with outcome	Each woman’s data were weighted to equalize the amount of data contributed to analysis
Missing outcome data
—Multiple imputation procedure produced 20 imputed datasets with plausible values for missing outcomes	Final results were summarized from the results from 20 imputed data sets
	Sensitivity to missing data was assessed with a secondary analysis restricted to cycles with observed outcome