Evidence map›Paper›PMID 23365621›Full record

ArticleComputational and mathematical methods in medicine2012

Application of seemingly unrelated regression in medical data with intermittently observed time-dependent covariates.

Sareh Keshavarzi, Seyyed Mohammad Taghi Ayatollahi, Najaf Zare, Maryam Pakfetrat

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Article in Computational and mathematical methods in medicine, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

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0cells of the map it votes in
3citing papers in PubMed
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2 · The registry

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3 · Its place in the literature

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3 citing papers in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

4 authors.

Sareh KeshavarziDepartment of Epidemiology, School of Health & Nutrition, Shiraz University of Medical Sciences, Shiraz, Iran.
Seyyed Mohammad Taghi Ayatollahi
Najaf Zare
Maryam Pakfetrat

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

BACKGROUND. In many studies with longitudinal data, time-dependent covariates can only be measured intermittently (not at all observation times), and this presents difficulties for standard statistical analyses. This situation is common in medical studies, and methods that deal with this challenge would be useful. METHODS. In this study, we performed the seemingly unrelated regression (SUR) based models, with respect to each observation time in longitudinal data with intermittently observed time-dependent covariates and further compared these models with mixed-effect regression models (MRMs) under three classic imputation procedures. Simulation studies were performed to compare the sample size properties of the estimated coefficients for different modeling choices. RESULTS. In general, the proposed models in the presence of intermittently observed time-dependent covariates showed a good performance. However, when we considered only the observed values of the covariate without any imputations, the resulted biases were greater. The performances of the proposed SUR-based models in comparison with MRM using classic imputation methods were nearly similar with approximately equal amounts of bias and MSE. CONCLUSION. The simulation study suggests that the SUR-based models work as efficiently as MRM in the case of intermittently observed time-dependent covariates. Thus, it can be used as an alternative to MRM.

Indexed as

Data Interpretation, StatisticalAlgorithmsComputational BiologyComputer SimulationData CollectionHumansLikelihood FunctionsMedical InformaticsModels, StatisticalRegression AnalysisRenal DialysisRenal InsufficiencyReproducibility of ResultsTime Factors

Identifiers

PMID23365621
PMCPMC3535884

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