Routine radiographs one day after anterior cervical discectomy and fusion are neither necessary nor cost-effective.

OBJECTIVES: Anterior cervical discectomy and fusion (ACDF) is a common operative treatment of compressive pathology of the cervical spinal cord, when caused by one or more degenerated intervertebral discs or related osteophytes. In addition to intra-operative radiographs to confirm spinal level before discectomy and implant position after insertion, traditional practice is to obtain post-operative antero-posterior and lateral plain radiographs (XR) before hospital discharge, despite a paucity of evidence supporting their benefit to patient care. Minimising unnecessary radiation to radiosensitive neck structures is desirable, and furthermore, with increasing financial pressure on healthcare resources, routine investigations should be clinically justified and evidence-based. We aim to compare the utility of routine post-operative cervical spine X-rays following ACDF. METHODS: We compare two groups of consecutive patients undergoing ACDF in a single UK neurosurgical centre. The first group (n = 109) received routine post-operative XR imaging, and the second group (n = 113) received radiographs only when clinically indicated. RESULTS: There were no differences in post-operative complication rates (4.6% vs. 5.3%), or requirement for further imaging or of further operative intervention (1.8% vs. 0.9%). The group that did not have routine post-operative radiographs had a significantly shorter stay in hospital (median two days vs. three days). There were no patients in either group where post-operative XR changed clinical management and mandated revision surgery or further imaging. All cases requiring surgery or further imaging were identified by clinical deterioration. CONCLUSIONS: We suggest that the practice of obtaining routine radiographs of the cervical spine following ACDF should be abandoned, unless there is a clear clinical indication

Effect sizes in ongoing randomized controlled critical care trials

BACKGROUND: An important limitation of many critical care trial designs is that they hypothesize large, and potentially implausible, reductions in mortality. Interpretation of trial results could be improved by systematic assessment of the plausibility of trial hypotheses; however, such assessment has not been attempted in the field of critical care medicine. The purpose of this study was to determine clinicians' views about prior probabilities and plausible effect sizes for ongoing critical care trials where the primary endpoint is landmark mortality. METHODS: We conducted a systematic review of clinical trial registries in September 2015 to identify ongoing critical care medicine trials where landmark mortality was the primary outcome, followed by a clinician survey to obtain opinions about ten large trials. Clinicians were asked to estimate the probability that each trial would demonstrate a mortality effect equal to or larger than that used in its sample size calculations. RESULTS: Estimates provided by individual clinicians varied from 0% to 100% for most trials, with a median estimate of 15% (IQR 10-20%). The median largest absolute mortality reduction considered plausible was 4.5% (IQR 3.5-5%), compared with a median absolute mortality reduction used in sample size calculations of 5% (IQR 3.6-10%) (P = 0.27). CONCLUSIONS: For some of the largest ongoing critical care trials, many clinicians regard prior probabilities as low and consider that plausible effects on absolute mortality are less than 5%. Further work is needed to determine whether pooled estimates obtained by surveying clinicians are replicable and accurate or whether other methods of estimating prior probability are preferred