J R Soc Med. 2003 Mar; 96(3): 118–121.
Five steps to conducting a systematic review
STEP 2: IDENTIFYING RELEVANT PUBLICATIONS
To capture as many relevant citations as possible, a wide range of medical,
environmental and scientific databases were searched to identify primary
studies of the effects of water fluoridation. The electronic searches were
supplemented by hand searching of
Index Medicus and
Excerpta
Medica back to 1945. Furthermore, various internet engines were searched
for web pages that might provide references. This effort resulted in 3246
citations from which relevant studies were selected for the review. Their
potential relevance was examined, and 2511 citations were excluded as
irrelevant. The full papers of the remaining 735 citations were assessed to
select those primary studies in man that directly related to fluoride in
drinking water supplies, comparing at least two groups. These criteria
excluded 481 studies and left 254 in the review. They came from thirty
countries, published in fourteen languages between 1939 and 2000. Of these
studies 175 were relevant to the question of safety, of which 26 used cancer
as an outcome
