[www.clinicaltrials.gov](http://www.clinicaltrials.gov) maintained by the U.S. National Institute of Health is a qualified registry, even though many other registries have become available since 0000 (Humphreys et al., [@B00]) maintained by the U.S. National Institute of Health is a qualified registry, even though many other registries have become available since 0000 (Humphreys et al., [@B00])