Analysis of the frequency, characteristics, and reasons for termination of shoulder- and elbow-related clinical trials

Abstract

Background: Clinical trials are key to the advancement of products and procedures related to conditions of the shoulder and elbow. Unfortunately, many trials are terminated prior to 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 shoulder- and elbow-related clinical trials. The current study set out to quantify completed and terminated shoulder- and elbow-related clinical trials, assess reasons for termination, and determine independent predictors of termination by comparing characteristics of completed and terminated trials.

Methods: The ClinicalTrials.gov database was queried on August 6, 2021, for all completed and terminated interventional studies registered to date using all available shoulder- and elbow-related search terms. Trial characteristics and reason for termination were abstracted. Univariate and multivariate analyses were performed using trial characteristics to determine independent predictors for trial termination.

Results: For shoulder-related trials, a total of 662 completed or terminated trials were identified and characterized, of which 51 (8%) were noted to have been terminated. For elbow-related trials, a total of 126 completed or terminated were identified and characterized, of which 16 (13%) were terminated. Difficulties with participant recruitment and/or retention was the individual reason most frequently reported for trial termination, accounting for 51% of terminated shoulder-related trials and 38% of terminated elbow-related trials. For shoulder-related trials, multivariate analysis of primary trial characteristics demonstrated increased odds of trial termination for industry-sponsorship (odds ratio [OR] = 4.2, P = .001) relative to sponsorship from local groups, and blinded studies (OR = 45.8, P = .0003) relative to studies that did not implement any form of blinding. For elbow-related trials, logistic regression did not reveal any of the primary trial characteristics evaluated to be correlated with odds of termination.

Conclusion: Shoulder- and elbow-related clinical trials were terminated at a rate of 8% and 13%, respectively. Difficulties in the recruitment and/or retention of participants were the reason most frequently reported for trial termination. For shoulder-related trials, industry sponsorship and studies with blinding were identified as independent predictors of termination. Given the ethical considerations and the opportunity costs associated with terminated studies, independent predictors and reasons for trial termination should be considered and addressed when possible to increase the rate of clinical trial completion.

Keywords: Clinical trials; blinding; clinical trial termination; elbow; epidemiology; interventional studies; shoulder.