Evaluation of the conjoint efficacy in Chinese medicine with the longitudinal latent variable linear mixed model

Chinese medicine (CM) clinical efficacy evaluation research involves the longitudinal multivariate measurement which means that patients are measured repeatedly and each patient is measured by several indicators on each fixed cross-section. Although each indicator can be evaluated separately with a longitudinal linear mixed model, it is important to consider all the endpoints together especially when researchers pay special attention to the change of the conjoint efficacy for several indicators in one patient. In this article, we introduce a latent variable linear mixed model to the CM conjoint efficacy evaluation and discuss why and how to analyze the longitudinal multivariate endpoint data in the clinical CM efficacy evaluation research. It may lead to the new insight of using such methodology in the field of conjoint efficacy evaluating of CM study. And with the definition of syndrome and symptom in the CM theory, the applied discussion brings the insight of CM syndrome evaluating in future. We illustrate this methodology using an example of CM efficacy evaluation from an ischemic stroke research.