The reproducibility of interventional radiology randomized controlled trials and external validation of a classification system

PURPOSE

The fragility index (FI) measures the robustness of randomized controlled trials (RCTs). It complements the P value by taking into account the number of outcome events. In this study, the authors measured the FI for major interventional radiology RCTs.

METHODS

Interventional radiology RCTs published between January 2010 and December 2022 relating to trans-jugular intrahepatic portosystemic shunt, trans-arterial chemoembolization, needle biopsy, angiography, angioplasty, thrombolysis, and nephrostomy tube insertion were analyzed to measure the FI and robustness of the studies.

RESULTS

A total of 34 RCTs were included. The median FI of those studies was 4.5 (range 1-68). Seven trials (20.6%) had a number of patients lost to follow-up that was higher than their FI, and 15 (44.1%) had a FI of 1-3.

CONCLUSION

The median FI, and hence the reproducibility of interventional radiology RCTs, is low compared to other medical fields, with some having a FI of 1, which should be interrupted cautiously.

The Complexity of Online Patient Education Materials About Interventional Neuroradiology Procedures Published by Major Academic Institutions

Introduction Health literacy is an independent predictor of population health status and is directly related to the readability of available patient education material. The National Institutes of Health (NIH) and the American Medical Association have recommended that patient education materials (PEMs) be written between a fourth- and a sixth-grade education level. The authors assessed the readability of online PEMs about neurointerventional procedures that have been published by several academic institutions across the US. Methods Online PEMs regarding five common neurointerventional procedures, including mechanical thrombectomy for large vessel occlusion, cerebral diagnostic angiography, carotid artery stenting, endovascular aneurysm embolization, and epidural steroid injection collected from the websites of 20 top institutions in Neurology and Neurosurgery. The materials were assessed via five readability scales and then were statistically analyzed and compared to non-institutional education websites (Wikipedia.com and WebMD.com). Results None of the PEMs were written at or below the NIH's recommended 6th-grade reading level. The average educational level required to comprehend the texts across all institutions, as assessed by the readability scales, was 10-11^th grade level. Some materials required a college-level education or higher. Material from non-institutional websites had significantly lower readability scores compared to the 20 institutions. Conclusions Current PEMs related to neurointerventional procedures are not written at or below the NIH's recommended fourth- to sixth-grade education level. Given the complexity of those procedures, significant attention should be pointed toward an improvement in the available online materials.

Quantitative analysis of tegmen bone mineral density in obese and non-obese patients

BACKGROUND

Certain factors have been linked to lateral skull base demineralisation or erosion, which may predispose to spontaneous cerebrospinal fluid leak. There are relatively few quantitative reports of skull base changes in patient populations.

METHOD

A novel refined measurement algorithm for quantification of tegmen bone mineral density was developed, and bone mineral density between obese and non-obese patient groups was compared. Computed tomography scans were analysed by three blinded reviewers, and tegmen bone mineral densities were compared.

RESULTS

There were 23 patients in the obese group and 27 matched controls in the non-obese group. Inter-rater reliability was 'strong' to 'near complete' (κ = 0.75-0.86). No differences in tegmen bone mineral density were found between the groups (p = 0.64). The number of active blood pressure medications correlated positively with lateral skull base bone mineral density.

CONCLUSION

A novel, refined, quantitative measurement algorithm for the assessment of tegmen bone mineral density was developed and validated. Obesity was not found to significantly affect tegmen bone mineral density.

The Reproducibility of Cerebrovascular Randomized Controlled Trials

BACKGROUND

Numerous randomized controlled trials (RCTs) relevant to the cerebrovascular field have been performed. The fragility index was recently developed to complement the P value and measure the robustness and reproducibility of clinical findings of RCTs.

OBJECTIVE

In this study, we evaluate the fragility index for key surgical and endovascular cerebrovascular RCTs and propose a novel RCT classification system based on the fragility index.

METHODS

Cerebrovascular RCTs reported between 2000 and 2018 were reviewed. Six key areas were specifically targeted in relation to stroke, carotid stenosis, cerebral aneurysms, and subarachnoid hemorrhage. The correlation between fragility index, number of patients lost to follow-up, and fragility quotient were evaluated to propose a classification system for the robustness of the studies.

RESULTS

A total of 20 RCTs that reported significant differences between both study groups in terms of the primary outcome were included. The median fragility index for the trials was 5.5. An additional 30 randomly selected RCTs were added to propose a classification system with high reliability. The difference between the number of patients lost to follow-up and fragility index inversely correlated with the fragility quotient and was used to divide the robustness of the RCTs into 3 classes reflecting the reproducibility of the trial.

CONCLUSIONS

Neurosurgeons and neurointerventionalists should exercise caution with interpreting the results of cerebrovascular RCTs, especially when the sample size and events numbers are small and there is a high number of patients who were lost to follow-up, as quantitatively identified using the proposed classification system.