Nature of work	Contributor(s)
Conception and design	Rahul Mhaskar, Benjamin Djulbegovic
Title and protocol development	Rahul Mhaskar, Hesborn Wao
Title and protocol revision	Rahul Mhaskar, Hesborn Wao, Benjamin Djulbegovic
Literature searches and study selection	Rahul Mhaskar, Hesborn Wao
Data extraction and management	Rahul Mhaskar, Hesborn Wao
Data analysis and interpretation	Rahul Mhaskar, Hesborn Wao, Benjamin Djulbegovic
Support for statistical analysis	Branko Miladinovic
Writing of first draft of the review	Rahul Mhaskar
Revision of review	Rahul Mhaskar, Ambuj Kumar, Benjamin Djulbegovic
Drafting plain language summary	Rahul Mhaskar
Final revision/approval of review	Rahul Mhaskar, Hesborn Wao, Branko Miladinovic, Benjamin Djulbegovic
Supervision of the study	Benjamin Djulbegovic