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In longitudinal data, a continuous response sometimes shows a profile approaching an asymptote. For such data, we propose a new class of models, autoregressive linear mixed effects models in which the current response is regressed on the previous response, fixed effects, and random effects. Asymptotes can shift depending on treatment groups, individuals,(More)
OBJECTIVE To determine smoking trends in Japan in comparison with lung cancer mortality. METHODS Age-specific smoking prevalence among cohorts born between 1897 and 1985 were determined for the period 1949-2010. The percentages of the cohorts born between 1893 and 1979 who initiated smoking early (e.g. before the age of 20 years) were determined. The(More)
BACKGROUND The National Nutrition Survey, Japan (NNS-J) provides annual anthropometric information for a whole nation over 50 years. Based on this survey, the mean body mass index (BMI) of Japanese men and elderly women has increased in recent decades, but that of young women has decreased. We examined the effect of birth cohort on this phenomenon. (More)
OBJECTIVE To compare growth curves of body mass index from children to adolescents, and then to young adults, in Japanese girls and women in birth cohorts born from 1930 to 1999. DESIGN Retrospective repeated cross sectional annual nationwide surveys (national nutrition survey, Japan) carried out from 1948 to 2005. SETTING Japan. PARTICIPANTS 76,635(More)
OBJECTIVE To show long-term trends of smoking initiation in Great Britain including unanalysed data and assess the impact of early smoking initiation on the lung cancer mortality in later ages focusing on birth cohorts. DESIGN Reanalysis of repeated cross-sectional surveys conducted 13 times during 1965-1987. SETTING Great Britain. PARTICIPANTS Men(More)
When primary endpoints of randomized trials are continuous variables, the analysis of covariance (ANCOVA) with pre-treatment measurements as a covariate is often used to compare two treatment groups. In the ANCOVA, equal slopes (coefficients of pre-treatment measurements) and equal residual variances are commonly assumed. However, random allocation(More)
In clinical data analysis, the restricted maximum likelihood (REML) method has been commonly used for estimating variance components in the linear mixed effects model. Under the REML estimation, however, it is not straightforward to compare several linear mixed effects models with different mean and covariance structures. In particular, few approaches have(More)
In clinical studies, dependent bivariate continuous responses may approach equilibrium over time. We propose an autoregressive linear mixed effects model for bivariate longitudinal data in which the current responses are regressed on the previous responses of both variables, fixed effects, and random effects. The equilibria are modeled using fixed and(More)
We are interested in longitudinal data of a continuous response that show profiles with an initial sharp change and approaching asymptotes for each patient, and many patients drop out with a reason related to the response. In this paper, we focus on a model that assumes a dropout process is missing at random (MAR). In this dropout process, we can obtain(More)
BACKGROUND Bitopertin, a glycine reuptake inhibitor, was investigated as a novel treatment for schizophrenia. We report all the results of a double-blind randomized study assessing safety and efficacy following 52-week adjunctive treatment with bitopertin in Japanese patients with schizophrenia. METHODS This study enrolled Japanese outpatients with(More)