Strategies to fit pattern.mixture models

Whereas most models for incomplete longitudinal data are formulated within the selection model framework, pattern.mixture models have gained considerable interest in recent years (Little, 1993, 1994).In this paper, we outline several strategies to fit pattern.mixture models, including the so.called identifying restrictions strategy.Multiple imputation is used to apply this strategy to realistic settings, such as quality.of.life data from a longitudinal study on metastatic breast cancer patients.