More than eight out of 10 pharma-sponsored clinical trials made it into a peer-reviewed journal, a 23% increase over the 2008 rate, researchers showed.

Executives interviewed think the hike is likely driven by more stringent demands for investigators to publish, said research firm Cutting Edge Information.

Drug companies are holding investigators more accountable for publishing to journals, the firm said. Many write publication clauses in contracts, making final milestone payments conditional on publication of trial results.

One drug company no longer accepts proposals from investigators unwilling to agree to write trial data up for publication, Cutting Edge said.