Quality assessment of the methods used in published opioid conversion reviews

The study objective was to assess methodological quality of opioid conversion systematic reviews. The electronic databases PubMed, EMBASE, and Scopus were used to identify the systematic reviews from the earliest available date until April 2012. Studies were not restricted based on type of opioid, country, or languages. Methodological quality was evaluated using the "Assessment of Multiple Systematic Reviews (AMSTAR)." A total of 2772 articles were found from which five met inclusions criteria. No review mentioned about the duplicate study selection and data extraction. Two reviews included a list of studies that were excluded studies. One study did not provided information on the characteristics of primary studies that were included. Of the three reviews that evaluated the quality of primary studies, two used the quality of included studies in formulating conclusions. Only two reviews provided information about conflicts of interest. Of the five included systematic reviews, three reached a moderate score; two had poor quality. Specific recommendations to improve methodological quality would include performing the data selection and extraction in duplicate, listing or showing the flowchart of studies that were included and excluded along with the reasons, including the main studies data illustrating tables, and including an assessment of the quality of the primary included studies.