5. Unit of analysis for included studies.

Unit of analysis	Studies reporting each type of unit of analysis
Average of both eyes	15 studies: Adler 2006; Chung 2002; COMET Study 2003a; COMET2 Study 2011; CONTROL Study 2016; Fujikado 2014; Fulk 1996; Fulk 2002; Hasebe 2008a; PIR‐205 Study 2004; Sankaridurg 2010; Schwartz 1981; Shih 1999; Tan 2005; Trier 2008
Right eye only	15 studies: Cambridge Anti‐Myopia Study 2013; Charm 2013; Cheng 2010; Cheng 2016; CLAMP Study 2004; DISC Study 2011; Edwards 2002; Houston Study 1987; Katz 2003; Koomson 2016; MIT Study 2001; ROMIO Study 2012; STAMP Study 2012; Yen 1989; Yi 2015
Right and left eyes reported as separate analyses	2 studies: Jensen 1991; Pärssinen 1989
One study eye randomized and treated per child	1 study: ATOM Study 2006
Child randomized and both eyes analyzed as independent units	2 studies: Hasebe 2014; Lu 2015
Paired‐eye design	2 studies: Anstice 2011; Swarbrick 2015
Eye with more severe myopia	1 study: Wang 2017
Not reported	3 studies: Han 2018; Wang 2005; Yang 2009

^aAverage values of both eyes were used if the correlation coefficient was > 0.85 between eyes and the mean difference (MD) was not statistically significant; otherwise the eye with more myopic change was used for each child (COMET Study 2003). Mean of both eyes or of right eye only (Hasebe 2008).