A quantitative analysis of clinical trial designs in spinal cord injury based on ICCP guidelines

Clinical studies of spinal cord injury (SCI) have evolved into multidisciplinary programs that investigate multiple types of neurological deficits and sequelae. In 2007, the International Campaign for Cures of SCI Paralysis (ICCP) proposed best practices for interventional trial designs, end-points, and inclusion criteria. Here we quantitatively assessed the extent to which SCI trials follow ICCP guidelines and reflect the overall patient population. We obtained data for all 288 SCI trials in ClinicalTrials.gov. We calculated summary statistics and observed trends pre-2007 versus 2007 onward. To compare the trial population to the overall SCI population, we obtained statistics from the National SCI Statistical Center. We generated tag clouds to describe heterogeneous trial outcomes. Most interventional studies were randomized (147, 73.1%), and utilized active (55, 36.7%) or placebo controls (49, 32.7%), both increasing trends (p=0.09). Most trials were open label (116, 53.5%), rather than double- (62, 28.6%) or single-blinded (39, 18.0%), but blinding has increased (p=0.01). Tag clouds of outcomes suggest an emphasis on assessment using scores and scales. Inclusion criteria related to American Spinal Injury Association (ASIA) status and neurological level allowed inclusion of most SCI patients. Age inclusion criteria were most commonly 18-65 or older. Consistent with ICCP recommendations, most trials were randomized and controlled, and blinding has increased. Age inclusion criteria skew older than the overall population. ASIA status criteria reflect the population, but neurological lesion criteria could be broadened. Investigators should make trial designs and results available in a complete manner to enable comparisons of populations and outcomes.