Figure 1.

Flow chart of the selected process, according to PRISMA guidelines: 151 reports were selected from PubMed, none of which were removed for duplication nor for foreign language. Seventy-six records were excluded by reading their abstracts because they dealt with the wrong topic. Seventy-five reports were analyzed full-length, fifty-seven of which were excluded: twenty-two dealt with the wrong population, twenty-six included outpatients, and ten had no data reported. One relevant report was found cited in another study and, therefore, was added to this research.