Study	Reason for exclusion
Billingham 2011	Data from this study were included in Ferry 2017.
Moro‐Sibilot 2015	No comparison between cisplatin and carboplatin
Schuette 2013	No comparison between cisplatin and carboplatin
Smit 2016	Post hoc analysis of another prospective trial
Sun 2014	Not a randomised clinical trial
Tiseo 2014	Not a randomised clinical trial
von Verschuer 2017	Prospective cohort study

All of the following publications are amongst the included trials, but were found in more than one database, as follows.

Saad 2017: found in PubMed, CENTRAL, and Embase databases; we excluded two of them.

Schuette 2013: found in PubMed, CENTRAL, and Embase databases; we excluded two of them.

Zatloukal 2003: found in PubMed, CENTRAL, and Embase databases; we excluded two of them.

Chen 2006: found in PubMed and CENTRAL databases; we excluded one of them.

Fossella 2003: found in PubMed and CENTRAL databases; we excluded one of them.

Cai 2002: found in PubMed and CENTRAL databases; we excluded one of them.

Yan 2001: found in PubMed and CENTRAL databases; we excluded one of them.

Schiller 2002: found in PubMed and CENTRAL databases; we excluded one of them.

Rosell 2002: found in PubMed and Embase databases; we excluded one of them.