The interconnection between the Dimensions database and Altmetric.com provides an opportunity to carry out a worldwide analysis on altmetrics coverage of scientific literature, analyzing the percentage of documents with altmetric mentions not only in general (indexed documents), but also filtered according to different units of analysis. In order to do so, the Dimensions Pro version database was directly used to retrieve 97,531,400 documents, which were subsequently filtered to obtain the top journals, countries, cities, institutions, research fields and funding bodies according to the total number of publications indexed in the database. For each entity and year of publication (from 2000 to 2017), the corresponding percentage of publications cited and the Altmetric Attention Score (% mentioned) were calculated. The main results indicate that the total number of publications with an Altmetric Attention Score (AAS) of one or over one is low (9.4% out of the total coverage), which has been highly concentrated in recent years, and higher for open access documents (18.9%), showing an open access altmetric advantage. Otherwise, English-speaking universities stand out, which determines an increase in the presence of specific cities from Anglo-Saxon countries, diminishing the presence in Japan, China, Russia or India, despite their elevated productivity. Multidisciplinary and medicine-related journals are also highlighted, which in turn influences the research disciplines with a higher AAS (% mentioned): Genetics, Immunology, Microbiology or Medical Microbiology. However, since the conducted analysis has brought out some inconsistencies in the quality of the data, results must be taken with caution. Publisher's Note: A corrigendum relating to this article has been published at http://doi.org/10.29024/joa.25.