Fig. 1

Presence of affiliations, email addresses and full first names in MEDLINE records as a function of publication date. The affiliations have been included (when available) since ~1988, most often containing the affiliation of the first-listed author or corresponding author only. Email addresses, although rarely available, have been included in the affiliation field since ~1995. Full first names have been included (when available) since 2002. Note that some first names and emails were extracted from bibliographic sources other than MEDLINE (see Results).