PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 11315038

Selection models and pattern-mixture models for incomplete data with covariates.

B Michiels·G Molenberghs·S R Lipsitz
View original source ↗Export metadata ↓

Abstract

Most models for incomplete data are formulated within the selection model framework. This paper studies similarities and differences of modeling incomplete data within both selection and pattern-mixture settings. The focus is on missing at random mechanisms and on categorical data. Point and interval estimation is discussed. A comparison of both approaches is done on side effects in a psychiatric study.

Explore related subjects

BiometryData Interpretation, StatisticalFemaleFluvoxamineHumansLikelihood FunctionsMaleMental DisordersModels, StatisticalSelective Serotonin Reuptake InhibitorsComparative StudyJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

B Michiels, G Molenberghs, S R Lipsitz. 1999. Selection models and pattern-mixture models for incomplete data with covariates.. https://doi.org/10.1111/j.0006-341x.1999.00978.x

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2003

Doppler flow velocity to measure the redistribution of fetal cardiac output in fetal stress.

The pathophysiologic continuum of poor uterine and placental blood flow associated with fetal growth restriction has to be considered the major cause of poor birth outcomes. The main attention in this context is drawn to the possibilities of an early diagnosis of imminent fetal compromise prior to and under delivery. With regard to this, the detection of a reduced fetal oxygen saturation (fetal stress) plays a crucial role, whereas an acute incident causing fetal hypoxemia has to be differentiated from a chronic hypoxemic condition. An acute hypoxemia under delivery is best detected by cardiotocography. Due to its infrequent and unpredictable occurrence, an acute antenatal hypoxemia usually escapes common surveillance methods. Fetal biometry and pulsed Doppler sonography are to be considered the most suitable methods to diagnose chronic hypoxemic fetal conditions. The interrogation of a combination of peripheral and central vessels allow the sonologist to characterize the extend of a progressively deteriorating oxygen supply. However, this correlation is not yet completely understood. Therefore, clinical consequences still have to be drawn by cardiotocographic findings indicating a global cardiac decompensation.

Biometry↗
PubMed2003

Colobomatous macrophthalmia with microcornea syndrome: report of a new pedigree.

Colobomatous macrophthalmia with microcornea syndrome (MIM 602499) is a very rare eye malformation. To date, only two families with a total number of eight patients have been reported. We report on 13 additional cases in a single three-generation family and describe the eye findings and quantitative parameters of corneal curvature and axial ocular dimensions. All affected relatives had bilateral involvement with typical inferonasal iris coloboma, chorioretinal coloboma, microcornea, and varying degrees of axial enlargement associated with myopia. Additional findings included flatter corneal curvatures and shallower anterior chambers. Iridocorneal angle abnormalities associated with elevation of intraocular pressure were detected in three patients. The pedigree confirms the autosomal dominant pattern of inheritance with complete penetrance.

Biometry↗
PubMed2003

Estimating the distribution of lag in the effect of short-term exposures and interventions: adaptation of a non-parametric regression spline model.

Information on the distribution of lag duration between exposure or intervention and the subsequent changes in risk can help in assessing the impact of exposure, predicting cost-effectiveness of intervention, and understanding the underlying biological mechanisms. Previous approaches focused more on optimizing the strength of the exposure-disease association than on directly estimating lag duration. We propose an alternative approach applicable to the analysis of the lagged effects of binary exposure variables. The density function of the distribution of lags is estimated based on flexible modelling of changes in hazard ratio of exposed versus unexposed subjects. The methodology is evaluated in a simulation study and is applied to the Framingham data to investigate the lagged effect of smoking cessation on coronary heart disease risk.

Biometry↗