Table 1.

Overview on instrument used in the parental and adolescent questionnaire

Construct	Instrument	Description	Reliability and validity
Parent questionnaire
Parents’ and child’s sociodemographics	Demographic standards68	Parent indicate their age, gender, migration background, education, employment and how many children under 18 are living in household. For their child, they indicate age, gender and school type.	–
Body mass index (BMI; child and parent)	Self-reported and proxy-reported weight and height	Parent report their weight and height as well as their children’s weight and height.
Current situation in school due to COVID-19	Single-item question	Due to COVID-19 pandemic, an additional question is used to indicate the current schooling situation: normal, home schooling or alternate lessons.	–
Degree of urbanisation	BIK regions69	Parents indicate the degree of urbanisation in dependence of inhabitants in their hometown (>100 000 inhabitants: city; 20 000–99 999 inhabitants: medium-sized town; 5000–19 999 inhabitants: small town; <5000 inhabitants: rural).	–
Home environment	Mobilität in Deutschland (MiD)45	Parents indicate car availability and bike availability (parent and child) and if they hold a driver license.	–
Distance to school	Single-item question	Parent indicate the distance to their child’s school from home in kilometres.	–
Aerobic PA guideline compliance	European Health Interview Survey—Physical Activity Questionnaire (EHIS-PAQ) (Finger et al., 2015)	Six items are used to indicate parental aerobic PA guideline compliance (at least 150 min aerobic PA per week).	The EHIS-PAQ is a reliable and valid tool to assess domain-specific PA as shown by adults from Germany (ICC=0.43–0.73).70
Joint physical activity with child	Modified item from the MoMo-Physical-Activity-Questionnaire (MoMo-AFB)71	Parents indicate on how many days in a normal week they are more than 60 min physically active with their child.	–
Active travel	Mobilität in Deutschland (MiD)45	To assess active travel in parents, they indicate transport mode, distance and accompaniment of child to four different destinations (work, friends’/relatives’ home, shopping and leisure time activities).	–
Perceived social and physical environment	Modified version of the Parental Perception of Barriers Towards Active Commuting to School (PABACS)72	A 24-item scale is used to assess parental barriers towards active travel including general aspects, barriers for walking and barriers for cycling.	In 207 parents, the questionnaire showed good internal consistency (α=0.86), moderate reliability (ICC=0.51–0.55) and moderate validity.72
Parents’ self-efficacy	Modified version of the Parents’ Self-efficacy Scale73	A 13-item scale is used to assess parents’ scheduling self-efficacy, parents’ barrier self-efficacy and parents’ support-seeking self-efficacy.	Cronbach’s α for the three first-order factors parents’ scheduling self-efficacy, parents’ barrier self-efficacy and parents’ support-seeking self-efficacy were 0.95, 0.86 and 0.76, respectively.73
Environmental self-identity	Environmental Self-identity Scale74	Parents indicate their agreement to three items on environmental friendliness.	The scale showed good internal consistency (α=0.870; average corrected item-total correlations=0.755).74
Health consciousness	Health Consciousness Scale75	Parents indicate their agreement to five items related to health practices on a 5-point Likert scale.	The scale showed good internal consistency (α=0.72).75
Adolescent questionnaire
WHO PA guideline compliance	MoMo-Physical-Activity-Questionnaire for Adolescents (MoMo-AFB)71	Adolescents indicate on how many days in a normal week they are physically active for 60 min or more.	In 9–17 year olds, the MoMo-AFB showed good test–retest reliability (ICC=0.68) and validity (Spearman r=0.29).76
Active travel	MiD45 and New Version of Mode and Frequency of Commuting To and From School77	Adolescents indicate transport mode, accompaniment and distance (in min and km) to school, to friends/relatives, to shopping opportunities and to leisure time activities.	The questionnaire is a reliable and feasible tool to assess active travel in adolescents (κ=0.61–0.94).77
Perceived social and physical environment	Modified Version of the Barreras percibidas en el desplazamiento activo al centro educativo (BATACE)78	An 18-item scale is used to assess perceived barriers to active travel including environmental and safety factors as well as planning and psychosocial barriers.	The BATACE showed good test–retest reliability (ICC range: 0.68–0.77) and internal consistency (α=0.59–0.76) in a sample of 465 adolescents.78
Perceived parental autonomy support for active travel	Modified Version of the Perceived Autonomy Support Scale for Active Commuting to and from School (PASS-ACS)79	A 4-item scale assesses perceived parental support for active travel.	The PASS-ACS is a valid and reliable (α=0.85; ICC=0.88) tool to assess adolescents’ perceived support for active travel.79
Basic psychological need satisfaction	Modified Version of the Basic Psychological Need Satisfaction in Active Commuting to and from School (BPNS-ACS)80	A 12-item scale is used to assess adolescents’ autonomy, competence and relatedness need satisfaction with regard to active travel behaviour.	In 675 students (10–18 years), the BPNS-ACS showed acceptable internal consistency (autonomy satisfaction α=0.81, competence satisfaction α=0.92 and relatedness satisfaction α=0.82) and predictive validity (total variance explained: 24%).80
Motivation for active travel	Modified version of the Behavioural Regulation in Active Commuting to and from School (BR-ACS) Questionnaire81	A 23-item scale is used to assess motivational regulation in active travel including intrinsic motivation, integrated, identified, introjected and external regulation, and amotivation.	In 404 secondary students, the BR-ACS showed adequate internal consistency (α=0.70–0.91) and stability (ICC=0.74) and predictive validity (total variance explained: 57%).81

Notes:

ICC, intraclass correlation coefficient; min, minutes; PA, physical activity; α, Cronbach's alpha; κ, Cohen’s Kappa.