Analyzing Group by Time Effects in Longitudinal Two-Group Randomized Trial Designs With Missing Data

Assessing Treatment Effects in Randomized Longitudinal Two-Group Designs with Missing Observations

چند رویکرد برخورد با مقادیر گمشده‌ متغیرهای کمی و بررسی اثر آنها بر نتایج حاصل از یک کارآزمایی‌ بالینی

Background and Objectives: A major challenge that affects the longitudinal studies is the problem of missing data. Missing in the data may result in the loss of part of the information which reduces the accuracy of the estimator and obtain the results will be biased and inaccurate. Therefore, it is necessary to evaluate the missing data mechanism from a longitudinal research and to consider thi...

معادلات برآورد تعمیم یافته و کاربرد آن در تحلیل داده های کولیک شیرخوارگی

Introdiuction and objective: Many Studies about Epidemiology and medical sciences that measured desired outcome at frequently individuals over times are done based on a longitudinal design. the features of a data set is repeated observes . For this reason , requirement of independence observation in longitudinal data is violated that causes this kind of data needs the specific statistical metho...

Design and analysis of group-randomized trials: a review of recent methodological developments.

We review recent developments in the design and analysis of group-randomized trials (GRTs). Regarding design, we summarize developments in estimates of intraclass correlation, power analysis, matched designs, designs involving one group per condition, and designs in which individuals are randomized to receive treatments in groups. Regarding analysis, we summarize developments in marginal and co...

A Comparative Review of Selection Models in Longitudinal Continuous Response Data with Dropout

Missing values occur in studies of various disciplines such as social sciences, medicine, and economics. The missing mechanism in these studies should be investigated more carefully. In this article, some models, proposed in the literature on longitudinal data with dropout are reviewed and compared. In an applied example it is shown that the selection model of Hausman and Wise (1979, Econometri...