PROQOLID specifies that to be eligible for inclusion in the database, a tool must meet the following criteria:
PROQOLID contains a few features that distinguish it from other research instruments databases such as Health & Psychosocial Instruments (HAPI) and PsycTESTS.
Over 75% of PROQOLID records contain a complete review copy of the instrument, rather than a few sample questions, as is often the case in other instrument databases.
Their content is not limited to COA-related instruments, as PROQOLID's is, and they dwarf PROQOLID in terms of content volume.
Although PROQOLID is more limited in scope and content, the quality of PROQOLID records seems to far exceed that of other validated research instrument databases.
PROQOLID does not offer a free trial period but does offer webinars to those who are interested in obtaining more information prior to subscribing.