Major trauma and the need for massive transfusion

Decision‐making in response to respiratory veno‐venous extracorporeal membrane oxygenation referrals: is current practice precise enough?

“…The conclusions of retrospective studies must always be interpreted with caution . Despite this, the general message seems to be that expert collaborative clinical assessment is, at present, an acceptable way to manage referrals to a SRFC for the consideration of VV‐ECMO.…”

Non‐inferiority studies: is ‘better’ the enemy of ‘good enough’?

“…A common method to set the value of Δ is through the use of previous studies of standard care as a form of historical control, although the use of historical controls has its own well‐described limitations , or even to consult meta‐analyses to come up with an appropriate value for Δ. Nevertheless, in some cases, no studies are available to allow an estimation of Δ, leaving researchers with no option but to guess or propensity match, which presents a range of difficulties in this setting .…”

Big data, big problems: causation, confounders and cohorts

“…The authors analysed the database of re‐imbursement claims spanning seven years from Taiwan's National Health Insurance Program to identify a suitable population. The readers are referred to a recent editorial commenting on the merits of retrospective designs , but in this narrative, we want to take the opportunity to comment on a few statistical terms and techniques in the context of the study by Chang et al…”

“…In retrospective analyses, propensity matching is commonly used to avoid imbalance between patient groups . Ideally, one would match each patient in the general anaesthesia group with a neuraxial anaesthesia patient that was an exact match in terms of each of the observed covariates (e.g.…”