Participants

A total of 16 Dutch sports clubs were included in the study, of which there were 8 with an outdoor SFP and 8 without an outdoor SFP (see table 1). The sports clubs were located in different regions in the Netherlands. Four major Dutch sports were included: soccer, tennis, field hockey and korfball. These sports differ in terms of socioeconomic status (SES) of their members and in team composition. Participating clubs (n=16) did not significantly differ from non-participating clubs (n=49) in terms of type of sports and level of urbanisation. Sports clubs were contacted either face-to-face or by phone, email and/or letter. The main reasons for non-participation were lack of interest (n=22), not having enough participants (n=11) and lack of time (n=8).

Characteristics of the participating sports clubs (n=16)

SFP, smoke-free policy.

At each sports club, focus group discussions (n=27) were conducted with adolescents aged 13–18 years old. Per club, two focus group discussions were conducted, with an exception of five clubs where only one focus group discussion was conducted because there were not enough boys or girls to form groups for both genders. Groups were divided by gender as adolescents’ responses might be influenced by the presence of the other gender.²⁵ A total of 180 adolescents participated in the study. Table 2 presents the characteristics of the participants, including gender, age and smoking status.

Characteristics of the participants (n=180)

*Defined by whether or not they smoked in the last 30 days.

SFP, smoke-free policy.