Preoperative prediction of intensive care unit stay following cardiac surgery

We have read the interesting article by Cocker et al. about a risk-model analysis for prolonged stay in the intensive care unit (ICU) [1]. The study is well designed and is an important contribution for everyday practice. Prolonged stay in the ICU poses important risks not only for mortality but also for the economic and ethical factors [2]. Various studies have also focused on this subject [3,4]. The risk factors are mostly common to every physician in this area; one of the factors is the presence of diabetes mellitus (DM) [3]. We have previously analyzed the determinants of mortality in this group of patients [2]. We found that DM is also a risk factor for mortality. I would like to ask about the patients with DM in this group. It can be seen that their analysis did not result similarly [1]. The resultant risk factors, however, are common for DM patients. Is there a possible explanation for this result? We would like to thank the authors for their study and would like to know their comments on the subject.