Testing treatment effect in schizophrenia clinical trials with heavy patient dropout using latent class growth mixture models.
Pharm Stat
; 15(4): 349-61, 2016 07.
Article
em En
| MEDLINE
| ID: mdl-27169874
ABSTRACT
By examining the outcome trajectories of the dropout patients with different reasons in the schizophrenia trials, we note that although patients are recruited from the same protocol that have compatible baseline characteristics, they may respond differently even to the same treatment. Some patients show consistent improvement while others only have temporary relief. This creates different patient subpopulations characterized by their response and dropout patterns. At the same time, those who continue to improve seem to be more likely to complete the study while those who only experience temporary relief have a higher chance to drop out. Such phenomenon appears to be quite general in schizophrenia clinical trials. This simultaneous inhomogeneity both in patient response as well as dropout patterns creates a scenario of missing not at random and therefore results in biases when we use the statistical methods based on the missing at random assumption to test treatment efficacy. In this paper, we propose to use the latent class growth mixture model, which is a special case of the latent mixture model, to conduct the statistical analyses in such situation. This model allows us to take the inhomogeneity among subpopulations into consideration to make more accurate inferences on the treatment effect at any visit time. Comparing with the conventional statistical methods such as mixed-effects model for repeated measures, we demonstrate through simulations that the proposed latent mixture model approach gives better control on the Type I error rate in testing treatment effect. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pacientes Desistentes do Tratamento
/
Esquizofrenia
/
Ensaios Clínicos Controlados Aleatórios como Assunto
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Modelos Estatísticos
Tipo de estudo:
Clinical_trials
/
Diagnostic_studies
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Guideline
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Humans
Idioma:
En
Revista:
Pharm Stat
Assunto da revista:
FARMACOLOGIA
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Estados Unidos