Paper
A black-box trial is not just overdue. It is a registry page that still tells the public remarkably little about what happened.
What appears when hiddenness is narrowed to black-box trials with no results, no linked publication, and no detailed description? We analysed 249,507 eligible older closed interventional studies from the March 29, 2026 full-registry snapshot. We defined a black-box trial as one with a two-year results gap, no linked publication reference, and no detailed description, then ranked sponsor classes, countries, and condition families. OTHER held the largest black-box stock at 21,375 studies, while INDUSTRY carried the highest large-class black-box rate at 23.4 percent. The United States still held 12,183 black-box studies on absolute stock, but healthy-volunteer portfolios were the sharpest condition-family extreme at 33.9 percent. The black-box view isolates a stricter silence state where industrial portfolios rate worse, while heterogeneous public and academic portfolios still dominate on count across the registry overall. Black-box status is a registry-visibility definition only and does not imply a study lacked internal documentation, external dissemination, or undiscovered reporting outside linked registry fields.