Table 1 Secondary outcomes measured in ‘Healthy Youngsters, Healthy Dads’ study

Fathers and children

Physical activity (accelerometer – LPA and MVPA) subgroup of 50 Fathers and children

• For every sequential block of 12 families that complete assessments, 5 were randomly allocated at baseline assessments to complete this measure

• One week of wrist-worn accelerometry using wGT3X-BT ActiGraph accelerometers (Actigraph, Pensicola, FL, USA) were used to assess light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) as average minutes per day. Data were downloaded and analysed using ActiLife version 6.13.4 (Actigraph, Pensacola, FL, USA)

Cut points and minimum wear-time:

• Preschool-aged children: Johansson [42] = sedentary ≤ 89 vertical counts (Y) and ≤ 221 vector magnitude (VM) counts per 5 s and ≥ 440 Y counts and ≥ 730 VM counts per 5 s for high-intensity physical activity. Minimum wear-time of 3 days, 7 h/day [43]

• Fathers: Montoye et al. [44] = VM count cut-points; < 2,860 counts/min (sedentary); 2,860–3,940 counts/min (light); and ≥ 3,941counts/min (moderate-to-vigorous (MVPA). Minimum wear time of 4 days/ 7 h [43]

Father-child co-physical activity

• 2-items adapted from the Youth Media Campaign Longitudinal Survey [45]

• Fathers reported on days per week they were physically active with their child one-on-one and with one or more family member

Weight

• Measured in light clothing, without shoes on a digital scale to 0.01 kg (model CH-150kp, A&D Mercury Pty Ltd, Australia)

• Weight was recorded at least twice until two measures fell within a range of 0.1 kg, averaged for the analysis

Height

• Measured using the stretch stature method on an electronic stadiometer to 0.1 cm (model BSM370, Biospace, USA)

• Height was recorded at least twice until two measures fell within a range of 0.3 cm, averaged for the analysis

BMI

• Calculated using the standard formula, weight (kg)/height in m²

• Children’s BMI-z scores were calculated using age- and sex-adjusted standardized scores (z-scores) based upon the UK reference data [46] and LMS methods [47]

• International Obesity Task Force cut points were used to determine overweight or obesity [48]

Body composition

• InBody720 bioelectrical impendence analyser, a multi-frequency bioimpedance device (Biospace Co., Ltd, Seoul, Korea) [49]

Fathers only

Physical Activity (Steps/day)

• One week of pedometry using Yamax SW200 pedometers (Yamax Corporation, Kumamoto City, Japan). Validated in adults [40]

• Asked to wear all waking hours (except when it could get wet or damaged) and to record steps on a log sheet for seven consecutive days

• Daily step count averages were included in the final analysis if they had completed at least 4 days (3 weekdays and 1 weekend day) of pedometry

Self-reported Moderate-to-vigorous physical activity (MVPA)

• Average weekly MVPA measured using modified version of the Godin Leisure Time Exercise Questionnaire [50]

• Participants reported average weekly bouts of moderate and vigorous physical activity and average bout length [51]. Values in each category were multiplied and summed to give an overall measure of weekly MVPA

Physical Activity Role Modelling

• Explicit role modelling scale (5-items) from the Activity Support Scale [52]

• Internal consistency coefficients has been found to be acceptable for the role modelling subscale among Caucasian parents (α = 0.88) [52]. In the current sample, the internal consistency was: α = 0.85

Screen time

• Adapted version of the Adolescent Sedentary Activity Questionnaire [53]

• Fathers reported the total time they spent sitting using screens (of any kind) for anything outside of work on each day in the previous week

• This adapted measure has shown good sensitivity to change in previous behaviour change research [36]

Screen time parenting practices

• Assessed with two questionnaires created for the purpose of the study

• 1. Screens other than TV represents use of devices other than TV in different contexts (e.g., at a social event, at a restaurant) (total of 7-items). Internal consistency for the current sample was: α = 0.71

• 2. Screens as reward is a single item questionnaire asking fathers if they offered screen based entertainment as a reward for good behaviour

Children only

Object Control Fundamental Movement Skill Competency

• Assessed with seven object control skills described in the validated Test of Gross Motor Development (kick, catch, two-handed and one-handed strike, dribble and overhand and underhand throw [TGMD-3]) [54])

• After watching two live demonstrations, children were filmed performing each skill twice and received a score of 0 or 1 for the presence or absence of various performance criteria (e.g., ball is caught by hands only)

• Combined scores for both attempts across all skills represented the overall object control score

Screen time (Mother proxy)

• Adapted version of the Adolescent Sedentary Activity Questionnaire [53]

• Mother reported the total time their child spent sitting using screens (of any kind) on each day in the previous week

• This adapted measure has shown good sensitivity to change in previous behaviour change research [36]

Process measures

Attendance

• Attendance rate at Fathers-only workshops

• Attendance rate across all eight sessions for fathers and children

Program satisfaction

• Process questionnaire developed to determine overall perceptions of program by fathers

• Questions were focused on program structure and timing, quality of facilitators, quality of program, quality of program resources (e.g., Activity Handbook), impact of program on behaviour and satisfaction levels

• A 5-point Likert scales from 1 (strongly disagree or poor) to 5 (strongly agree or excellent) was used

Fidelity

• Process questionnaire developed for the study to determine overall perceptions of facilitators

• Completed by program facilitators

• Questions focused on delivery of content for all sessions (e.g., There was sufficient time to get through all the content) and perceptions of enjoyment from father and child (e.g., The youngsters enjoyed the practical session)

• A 5-point Likert scale from 1 (strongly disagree) to 5 (strongly agree) was used

• Number and % of practical sessions with all required content delivered. Facilitators were asked to indicate any sessions where they were unable to deliver as intended (e.g., “If you were unable to complete any rough and tumble activities, please tick the activities you missed below”)