%0 Journal Article %1 Pirracchio2011 %A Pirracchio, Romain %A Sprung, Charles L %A Payen, Didier %A Chevret, Sylvie %D 2011 %J Journal of clinical epidemiology %K 80andover Adult AgeDistribution Aged CohortStudies ConfidenceIntervals ConfoundingFactors(Epidemiology) France France:epidemiology HospitalMortality Humans IntensiveCareUnits MiddleAged PatientAdmission PatientAdmission:statistics&numericaldata PropensityScore RiskFactors SelectionBias Triage %N 12 %P 1373-82 %R 10.1016/j.jclinepi.2011.02.009 %T Utility of time-dependent inverse-probability-of-treatment weights to analyze observational cohorts in the intensive care unit. %U http://www.ncbi.nlm.nih.gov/pubmed/21652175 %V 64 %X OBJECTIVE: When analyzing observational databases, marginal structural models (MSMs) may offer an appealing approach to estimate causal effects. We aimed at evaluating MSMs, in accounting for confounding when assessing the benefit of intensive care unit (ICU) admission and on its interaction with patient age, as compared with propensity score (PS) matching. STUDY DESIGN AND SETTING: PS and inverse-probability-of-treatment weights for MSMs were derived from an observational study designed to evaluate the benefit of ICU admission on in-hospital mortality. Only first ICU triages (time-fixed weights) or whole triage history (time-dependent weights) were considered. Weights were stabilized by either the prevalence of the actual treatment or the probability of the actual treatment given baseline covariates. Risk difference (RD) was the main outcome measure. RESULTS: MSMs with time-dependent weights offered the best reduction in the baseline imbalances as compared with PS matching. No effect of ICU admission on in-hospital mortality was found (RD=0.010; 95% confidence interval=-0.038, 0.052) with no interaction between age and treatment. CONCLUSION: MSMs appear interesting to handle selection bias in observational studies. When confounding evolves over time, the use of time-dependent weights should be stressed out. %@ 1878-5921; 0895-4356

@article{Pirracchio2011, abstract = {OBJECTIVE: When analyzing observational databases, marginal structural models (MSMs) may offer an appealing approach to estimate causal effects. We aimed at evaluating MSMs, in accounting for confounding when assessing the benefit of intensive care unit (ICU) admission and on its interaction with patient age, as compared with propensity score (PS) matching. STUDY DESIGN AND SETTING: PS and inverse-probability-of-treatment weights for MSMs were derived from an observational study designed to evaluate the benefit of ICU admission on in-hospital mortality. Only first ICU triages (time-fixed weights) or whole triage history (time-dependent weights) were considered. Weights were stabilized by either the prevalence of the actual treatment or the probability of the actual treatment given baseline covariates. Risk difference (RD) was the main outcome measure. RESULTS: MSMs with time-dependent weights offered the best reduction in the baseline imbalances as compared with PS matching. No effect of ICU admission on in-hospital mortality was found (RD=0.010; 95% confidence interval=-0.038, 0.052) with no interaction between age and treatment. CONCLUSION: MSMs appear interesting to handle selection bias in observational studies. When confounding evolves over time, the use of time-dependent weights should be stressed out.}, added-at = {2023-02-03T11:44:35.000+0100}, author = {Pirracchio, Romain and Sprung, Charles L and Payen, Didier and Chevret, Sylvie}, biburl = {https://www.bibsonomy.org/bibtex/24afdefc3705a905cd7525e22b9380d00/jepcastel}, city = {Department of Biostatistics, Hopital Saint Louis, Universite Paris 7 Diderot, Paris, France. romainpirracchio@yahoo.fr}, doi = {10.1016/j.jclinepi.2011.02.009}, interhash = {f72bf5f14dd59d8dbe270d0f6dc578dc}, intrahash = {4afdefc3705a905cd7525e22b9380d00}, isbn = {1878-5921; 0895-4356}, issn = {1878-5921}, journal = {Journal of clinical epidemiology}, keywords = {80andover Adult AgeDistribution Aged CohortStudies ConfidenceIntervals ConfoundingFactors(Epidemiology) France France:epidemiology HospitalMortality Humans IntensiveCareUnits MiddleAged PatientAdmission PatientAdmission:statistics&numericaldata PropensityScore RiskFactors SelectionBias Triage}, month = {12}, note = {6952<m:linebreak></m:linebreak>CI: Copyright (c) 2011; JID: 8801383; 2010/01/30 [received]; 2011/01/21 [revised]; 2011/02/21 [accepted]; 2011/06/11 [aheadofprint]; ppublish;<m:linebreak></m:linebreak>Anàlisi de dades; Dades longitudinals; Marginal structural models}, number = 12, pages = {1373-82}, pmid = {21652175}, timestamp = {2023-02-03T11:44:35.000+0100}, title = {Utility of time-dependent inverse-probability-of-treatment weights to analyze observational cohorts in the intensive care unit.}, url = {http://www.ncbi.nlm.nih.gov/pubmed/21652175}, volume = 64, year = 2011 }