Both search strategies, with and without full text, were able to find the particular drug/ADE pair mentioned in letters before the corresponding Micromedex reference. However, using fulltext search outperformed title/MeSH-based search, not only based on the number of drug/ADE pairs found but also on the time of detection. The percentage of letters in the dataset that are not related to specific articles is 0.6% using title/MeSH, 2.1% using title/full-text. Furthermore, we found that MeSH terms are not always reliable. For example, some of the letters had MeSH terms like ''Adverse Effect'' but no mention of adverse effects in the letter. Not surprisingly, since MeSH is a controlled vocabulary, some of these terms do not appear in the full text of the letters. These findings are shown in Table 1 .