Randomized controlled trials and neurosurgery: the ideal fit or should alternative methodologies be considered?

Randomized-controlled trials (RCTs) are advocated to provide high-level medical evidence. However, in neurosurgery, there are barriers to conducting RCTs. The authors of this study sought to analyze the quality of neurosurgical RCTs since 2000 to determine the adequacy of their design and reporting.

A search of the MEDLINE and EMBASE databases (2000-2014) was conducted. The medical subject heading (MeSH) terms used in the search included: "neurosurgery" OR "neurosurgical procedure," "brain neoplasms," "infarction" and "decompression," "carotid stenosis," "cerebral hemorrhage," and "spinal fusion." These studies were limited to RCTs, in humans, and in the English language. The Consolidated Standards for Reporting of Trials (CONSORT) and Jadad scales were used to assess the quality of RCT design and reporting. The standardized median times cited (median citations divided by years since publication) were used to assess impact. A pragmatic-explanatory continuum indicator summary-based scale was used to assess the design of the studies as primarily pragmatic or explanatory.

Sixty-one articles were identified, and the following subspecialties were the most common: vascular (23, 37%), followed by functional neurosurgery and neurooncology (both 13, 21%). The following nations were the primary leaders in RCTs: US (25 studies, 41%), Germany (8 studies, 13%), and the United Kingdom (7 studies, 11%). Median sample size was 100 (interquartile range [IQR] 41.5-279). The majority of the studies (40, 66%) had pragmatic objectives. The median number of times cited overall was 69 (IQR 20.5-193). The combined median CONSORT score was 36 (IQR 27.5-39). Blinding was most deficiently reported. Other areas with a relatively low quality of reporting were sample size calculation (34.2% of surgical, 38.5% of drug, and 20% of device studies), allocation concealment (28.9% of surgical, 23.1% of drug, and 50% of device studies), and protocol implementation (18.4% of surgical, 23% of drug, and 20% of device studies). The quality of reporting did not correlate with the study impact. All studies had a median Jadad score ≤ 3. Thirty-three pragmatic studies (83%) and 5 explanatory studies (25%) met the design objectives. All pragmatic studies based on drug and device trials met their objectives, while 74% of pragmatic surgical trials met their objectives.

The prevalence of neurosurgical RCTs is low. The quality of RCT design and reporting in neurosurgery is also low. Many study designs are not compatible with stated objectives. Pragmatic studies were more likely to meet design objectives. Given the role of RCTs as one of the highest levels of evidence, it is critical to improve on their methodology and reporting.