Analysis of failure time hierarchical data in the presence of competing risks with application to oral contraceptive pill use in Egypt

Problems of practical interest in the analysis of data on contraceptive use , from Demographic and Health Surveys (DHS), include the estimation of the cause-specific probability of discontinuation by time t (the cumulative inc idence function), in the presence of other competing causes and the evaluat ion of the effect of covariates on the cause-specific hazards of discontinu ation. Methods of analysis of failure time data with competing risks are by now fairly well developed in the case of a simple random sample. However, the data from the DHS are clustered by geographical areas and include multi ple episodes per woman. For a marginal (population average) approach, we pr opose using methods developed for simple random samples with standard error s calculated using a double bootstrap to take account of the clustered hier archical nature of the data. In the conditional approach, the cause-specifi c hazards are modelled as log-linear functions of the covariates conditiona l on random effects of clusters and women, using a three-level multinomial discrete-time logit model. The methods are applied to data from Egypt 1992 DHS on the oral contraceptive pill use. Copyright (C) 2001 John Wiley & Son s, Ltd.