A profile of key characteristics was developed for each included study (see Appendix ). Each study profile provides the level of evidence, design and quality of the study, authors, publication year, location, criteria for including/excluding patients, study population characteristics, type of intervention, comparator intervention and/or reference standard (where relevant), and outcomes assessed. Studies that could not be retrieved or that met the inclusion criteria but contained insufficient or inadequate data for inclusion are listed in Appendix . Definitions of all technical terms and abbreviations are provided in the Glossary (page 18). Descriptive statistics were extracted or calculated for all safety and effectiveness outcomes in the individual studies.