eTable 5. Quality assessment of survey studies on analgesic use in high-performance and amateur sport.

Study (reference)	Selection	Comparability	Outcome	Total (max. 9)
Aavikko et al. (2013) (17)	****	**	*	7
Alaranta et al. (2006) (18)	****	**	*	7
Broman et al. (2017) (20)	****	*	*	6
Brune et al. (2009) (22)	**		*	3
Chlíbková et al. (2018) (24)	**		*	3
Didier et al. (2017) (27)	****	*	*	6
Dietz et al. (2016) (28)	****	**	*	7
Dowse et al. (2011) (29)	****	*	*	6
Gorski et al. (2011) (30)	**		*	3
Hoffmann and Fogard (2011) (32)	****	*	*	6
Holmes et al. (2013) (34)	*		*	2
Joslin et al. (2013) (35)	**		*	3
Küster at al. (2013) (38)	****	**	*	7
Lai-Cheung-Kit et al. (2019) (39)	****	*	*	6
Mahn et al. (2018) (40)	****	**	*	7
Martínez et al. (2017) (e1)	****	*	*	6
Pardet et al. (2017) (e5)	****	*	*	6
Rosenbloom et al. (2020) (e7)	****	*	*	6
Rossi et al. (2021) (e8)	****	**	*	7
Rotunno et al. (2018) (e9)	****	**	*	7
Rüther et al. (2018) (e10)	****	*	*	6
Schneider et al. (2019) (e11)	****	**	*	7
Seifarth et al. (2019) (7)	****	*	*	6
Taioli (2007) (e13)	****	*	*	6
Whatmough et al. (2017) (e24)	**		*	3

Newcastle Ottawa Scale (NOS) for evaluating cohort studies:

The individual studies are scored for selection (representativeness of the exposed cohort and selection of the non-exposed cohort; ascertainment of exposure; demonstration that outcome of interest was not present at start of study), comparability, and recording of exposure/endpoint (validity of the data provided [outcome], endpoint within a sufficient observation period, consideration of and control for missing data).

Where the risk of bias is low, one star is given; the maximum possible number of stars is nine (16).