NAH revised the protocol and provided general advice.

YHN (the contact person) organised the review teamwork, wrote the ‘Objectives’, ‘Unit of analysis issues’, ‘Sensitivity analysis’, ‘Search methods for identification of studies’, ‘Acknowledgements’, ‘Contributions of authors’ and 'Declarations of interest' sections of the protocol, responded to peer reviewer comments, checked the data entered into the RevMan 5.3, and commented on every section in the protocol main text.

YAD and YHN wrote the ’Criteria for considering studies for this review’ section for the protocol. YAD also checked the correct use of grammar in the ‘Description of the condition’ ‘Description of the intervention’, ‘Why it is important to do this review’ sections, and commented on every section in the main text of the protocol.

YA wrote the ‘Description of the condition’ and ‘Glossary of terms’ sections of the protocol, checked the correct use of grammar, entered data into RevMan 5.3, and commented on the sections ‘Description of the intervention’, ‘How the intervention might work’, ‘Why it is important to do this review’, ‘Objectives’, ‘Criteria for considering studies for this review’, ‘Measures of treatment effect’, ‘Unit of analysis issues’, and ‘Subgroup analysis and Investigation of heterogeneity’.

HAS wrote the ‘Data extraction and management’, ‘Measures of treatment effect’, ‘Dealing with missing data’, ‘Assessment of heterogeneity’, and ‘Assessment of reporting biases’ sections of the protocol, and commented on the section ‘Criteria for considering studies for this review’.

FA wrote the ‘Assessment of risk of bias in included studies’ and ‘Reaching conclusions’ sections of the protocol, checked for the correct use of grammar, and commented on the ‘Description of the intervention’, ‘Objectives’, and ‘Criteria for considering studies for this review’ sections.

HAS and FA wrote the section ‘How the intervention might work’.

HAS, FA, and YHN wrote the section ‘Why it is important to do this review’.

FA and YHN wrote the section ‘Subgroup analysis and investigation of heterogeneity’.

HAS wrote the ‘Description of the intervention’ section.

AH wrote the ‘Selection of studies’ and ‘Data synthesis’ sections of the protocol, and commented on the section ‘Criteria for considering studies for this review’.