Analysis of the Frequency, Characteristics, and Reasons for Termination of Spine-related Clinical Trials

Study Design: Cross-sectional analysis of completed and terminated spine-related clinical trials in the ClinicalTrials.gov registry. Objective: The aim was to quantify completed and terminated spine-related clinical trials, assess reasons for termination, and determine predictors of termination by comparing characteristics of completed and terminated trials. Summary of Background Data: Clinical trials are key to the advancement of products and procedures related to the spine. Unfortunately, trials may be terminated before completion. ClinicalTrials.gov is a registry and results database maintained by the National Library of Medicine that catalogs trial characteristics and tracks overall recruitment status (eg, ongoing, completed, terminated) for each study as well as reasons for termination. Reasons for trial termination have not been specifically evaluated for spine-related clinical trials. Methods: The ClinicalTrials.gov database was queried on July 20, 2021 for all completed and terminated interventional studies registered to date using all available spine-related search terms. Trial characteristics and reason for termination, were abstracted. Univariate and multivariate analyses were performed determine predictors of trial termination. Results: A total of 969 clinical trials were identified and characterized (833 completed, 136 terminated). Insufficient rate of participant accrual was the most frequently reported reason for trial termination, accounting for 33.8% of terminated trials. Multivariate analysis demonstrated increased odds of trial termination for industry-sponsorship [odds ratio (OR)=1.59] relative to sponsorship from local groups, device studies (OR=2.18) relative to investigations of drug or biological product(s), and phase II (OR=3.07) relative to phase III studies (P<0.05 for each). Conclusions: Spine-related clinical trials were found to be terminated 14% of the time, with insufficient accrual being the most common reason for termination. With significant resources put into clinical studies and the need to advance scientific objectives, predictors, and reasons for trial termination should be considered and optimized to increase the completion rate of trials that are initiated.