The combination of key words
using ‘Boolean’ operators truncation,
phrase searching and MeSH key
words were also used in the search strategies. The following
databases were searched: MEDLINE (1966 – present);
EMBASE (1980 – present); CINAHL (1982 – present); and,
the Cochrane library up to and including 2009 Issue 4. In
addition, a manual search of the references of all possible
books and journals was performed.