... sum-marized in additional files 5 and 6. Totally four studies[13,16,17,19] rank high quality according to Jadad Scale.Because of lack of appropriate blinding, all the studieswere rated as zero at the ... qual-ity and data abstraction. Structured data extractionforms were used to extract data on the characteristics of individual studies. Inform ation was collected on partici-pants (age, sex, diagnostic ... shiqiyun@hotmail.com1Department of Clinical Epidemiology and Biostatistics, McMaster University,Hamilton, Ontario, L8S 4L8, CanadaFull list of author information is available at the end of the articleShi and MacDermid...