British journal of anaesthesia
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Review Meta Analysis
Bayesian analysis of a systematic review of early versus late tracheostomy in ICU patients.
A recent systematic review and meta-analysis of RCTs of early vs late tracheostomy in mechanically ventilated patients suggest that early tracheostomy reduces the duration of ICU stay and mechanical ventilation, but does not reduce short-term mortality or ventilator-associated pneumonia (VAP). Meta-analysis of randomised trials is typically performed using a frequentist approach, and although reporting confidence intervals, interpretation is usually based on statistical significance. To provide a robust basis for clinical decision-making, we completed the search used from the previous review and analysed the data using Bayesian methods to estimate posterior probabilities of the effect of early tracheostomy on clinical outcomes. ⋯ Bayesian meta-analysis suggests a high probability that early tracheostomy compared with delayed tracheostomy has at least some benefit across all clinical outcomes considered.
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Post-dural puncture headache (PDPH) is a well-recognised complication of neuraxial procedures. Although it is generally considered to be self-limiting, there is mounting evidence suggesting an association between PDPH and chronic headaches. In this review, chronic headache after dural puncture was defined as the reporting of persistent headaches more than 1 month after the index dural puncture. ⋯ Overall, the level of evidence is low for all reported outcomes (aetiology, intervention and outcome) by virtue of the type of studies available (cohort and case reports) and significant risk of bias in the cohort studies. Based on findings from this review, we recommend that the risk of chronic headache is included in the informed consent discussion for all neuraxial procedures. Patients with PDPH should be closely followed up after hospital discharge.
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Exposure to general anaesthesia in children might increase the risk of long-term behavioural problems. It is unclear if any behavioural changes in the short term after anaesthesia could be associated with long-term problems. The goal of the current study was to evaluate the short-term trajectory of parent-reported behaviour measured by the Behaviour Assessment System for Children, third edition (BASC-3) amongst children aged 2.5-6 yr who underwent general anaesthesia for elective surgery. ⋯ Anaesthesia for elective surgery in young children was associated with a small decrease in internalising problems but no changes in other areas of behavioural problems when assessed at 3 months postoperatively, including in children with prior exposure to anaesthesia.
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Editorial Comment
Trials with 'non-significant' results are not insignificant trials: a common significance threshold distorts reporting and interpretation of trial results.
We discuss a newly published study examining how phrases are used in clinical trials to describe results when the estimated P-value is close to (slightly above or slightly below) 0.05, which has been arbitrarily designated by convention as the boundary for 'statistical significance'. Terms such as 'marginally significant', 'trending towards significant', and 'nominally significant' are well represented in biomedical literature, but are not actually scientifically meaningful. ⋯ Instead, investigators could simply report their findings: effect sizes, P-values, and confidence intervals (or their Bayesian equivalents), and leave it to the discerning reader to infer the clinical applicability and importance. Our goal should be to move away from describing studies (or trials) as positive or negative based on an arbitrary P-value threshold, and rather to judge whether the scientific evidence provided is informative or uninformative.