CHEST Guidelines-Response_chest

Response_chest_57

Pdf Summary

The document discusses the potential biases and methodologies in studies examining anticoagulation treatments for patients with conditions like antiphospholipid syndrome (APS) and catastrophic antiphospholipid syndrome (CAPS). A critique was provided concerning the potential for immortal time bias, where beneficial treatment effects might be exaggerated due to biases in the study's retrospective nature, which included data from multiple centers over nearly two decades.<br /><br />The authors Chen, Lu, and Qian suggest using approaches like time-varying covariates or propensity score matching to mitigate biases. They note selection bias issues, where indications or contraindications for treatments might differ across patient groups.<br /><br />In response, Pineton de Chambrun et al. explain their study's context, highlighting that it involved a rare disease, making prospective studies challenging. They defend the decision to account for treatments received before ICU admission and claim that nonsurvivors, who were less likely to have received anticoagulation due to contraindications like bleeding risks, had longer stays comparable to survivors. This suggests that anticoagulation decisions were often dictated by patient health risks rather than study bias.<br /><br />Additionally, they emphasize that anticoagulation has been a recommended treatment for APS and CAPS, aligning with past literature. Despite acknowledging potential biases in study design, they argue that these do not undermine the study's internal validity or its conclusions about the importance of anticoagulation in critically ill APS patients.<br /><br />Further, the discussion also touches on a separate review regarding bronchoscopy in managing hemoptysis, highlighting misinterpretations and clarifying study findings related to bronchoscopy's diagnostic abilities in mild versus severe cases.<br /><br />In conclusion, the discourse around these studies underlines the complexities in treatment outcome studies, especially when dealing with rare conditions and retrospective data, while emphasizing the need for careful methodological consideration to ensure accurate interpretations.

Keywords

anticoagulation

antiphospholipid syndrome

catastrophic antiphospholipid syndrome

immortal time bias

retrospective study

time-varying covariates

propensity score matching

selection bias

bronchoscopy

treatment outcomes