Among the several options available for searching the scientific literature Medline proved to be the most useful and complete. The output produced out of other databases such as Current Contents and Dialogue did not provide additional references when using similar keywords. Search criteria . Medline can be searched by subject, key word or title word, as well as by the usual author and journal descriptors. We chose to search by key word as it produces a larger output than the subject descriptors.
Key words are any words that appear on the title and the abstract.
Searches are conducted at each level of aggregation. Concept terms are combined among themselves to reduce the chances of duplicated and non-relevant hits. This is again conducted excluding major key terms. A final search is conducted by author, using for this only the names of authors who's work appear with highest frequency. References cited in selected health policy and health reform reviews are scanned for final confirmation.