Portal de Periódicos da CAPES

Survivor treatment bias, treatment selection bias, and propensity scores in observational research

2010; Elsevier BV; Volume: 63; Issue: 2 Linguagem: Inglês

10.1016/j.jclinepi.2009.05.009

1878-5921

Peter C. Austin, Robert W. Platt,

Statistical Methods and Inference

We would like to thank the editors for the invitation to comment on the article by Tleyjeh et al. published in this issue of the journal [ [1] Tleyjeh IM, Ghomrawi HMK, Steckelberg JM, Montori VM, Hoskin TL, Enders F, et al. Conclusion about the association between valve surgery and mortality in an infective endocarditis cohort changed after adjusting for survivor bias. J Clin Epidemiol 2010;63:130–5 [in this issue]. Google Scholar ]. Tleyjeh et al. address the important issue of survivor treatment bias in observational studies and then propose two statistical methods for accounting for this bias. Studies with time-to-event outcomes in which the exposure of interest occurs during the same period during which outcomes occur can be susceptible to survivor treatment bias, also referred to as "immortal time bias" [ [2] Suissa S. Immortal time bias in pharmacoepidemiology. Am J Epidemiol. 2008; 167: 492-499 Crossref PubMed Scopus (1005) Google Scholar ] or "time-dependent bias" [ 3 van Walraven C. Davis D. Forster A.J. Wells G.A. Time-dependent bias was common in survival analyses published in leading clinical journals. J Clin Epidemiol. 2004; 57: 672-682 Abstract Full Text Full Text PDF PubMed Scopus (244) Google Scholar , 4 Beyersmann J. Wolkewitz M. Schumacher M. The impact of time-dependent bias in proportional hazards modelling. Stat Med. 2008; 27: 6439-6454 Crossref PubMed Scopus (66) Google Scholar , 5 Beyersmann J. Gastmeier P. Wolkewitz M. Schumacher M. An easy mathematical proof showed that time-dependent bias inevitably leads to biased effect estimation. J Clin Epidemiol. 2008; 61: 1216-1221 Abstract Full Text Full Text PDF PubMed Scopus (126) Google Scholar ].