Chen 2011.

Study characteristics
Methods	Study name: Web ABC study Study design: RCT Intervention period: 8 weeks Follow‐up period (post‐intervention): 6 months Differences in baseline characteristics: reported Reliable outcomes: reported Protection against contamination: NR Unit of allocation: individual Unit of analysis: individual
Participants	N (controls baseline) = 27 N (controls follow‐up) = 24 N (interventions baseline) = 27 N (interventions follow‐up) = 26 Setting (and number by study group): 54 participants (N = 27 intervention; N = 27 control) from community centres Recruitment: convenience sample of 12‐15‐year‐old participants who accessed community programmes Geographic region: San Francisco, USA Percentage of eligible population enrolled: 86% Mean age: (intervention + control:12.52 (3.15) Sex: intervention, 41% female; control, 52% female
Interventions	Aim: to examine the efficacy of the Web ABC programme in promoting healthy lifestyles and healthy weight in Chinese‐American adolescents. Intervention was designed to be individually tailored to the behavioural stage of the adolescent. For instance, if the adolescent was in the 'Preparation' stage in PA area, he/she would receive information on ways of being active and various types of fun activities he/she could do. Both adolescent and parental sessions/lessons lasted 15 min each. Content/themes of the 8‐week adolescent programme included the following Week 1: understanding how the body works and how to recognise and cope with feelings Week 2: apply adequate problem‐solving techniques and develop healthy coping skills Week 3: use various relaxation techniques and develop healthy coping skills Week 4: nutrition 101: understanding food and health Week 5: nutrition 102: make smart food choices Week 6: understanding the importance of an adequate activity level Week 7: being cool and active: various fun activities for youth and families Week 8: being yourself and using fun ways to improve your health and maintain a healthy lifestyle There were 3 internet sessions for parents designed to coach parents in the skills needed to help their adolescents improve their progress toward healthy lifestyles and healthy weights. Participants could log on to the programme and complete sessions/lessons from home, the library, or the community centre. Completed online therefore no need for a facilitator. Control group details: participants in the control group also logged on to the website using a preassigned username and password. Every week for 8 weeks, adolescents received general health information that was not tailored, adapted from the American Academy of Pediatrics, the CDC, and the American Heart Association, related to nutrition, dental care, safety, common dermatology care, and risk‐taking behaviours using similar format as the intervention group (text, graphics, comics, and voice‐over). Parents also received three internet sessions related to general information on the topics taught in the control group. Information was presented in English to the adolescents and in English and Chinese to the parents. Each lessons lasted for about 15 min. Diet and PA combined intervention vs control
Outcomes	Outcome measures Primary: BMI Secondary: waist‐to‐hip ratio, blood pressure, PA, food intake, diet and PA knowledge, diet and PA self‐efficacy Process evaluation: NR (NB log‐on rate)
Implementation‐related factors	Theoretical basis: TTM‐Stages of Change and SCT Resources for intervention implementation: NR Who delivered the intervention: reported – internet‐based PROGRESS categories assessed at baseline: child: gender; parent: race/ethnicity (acculturation) education, occupation, SES (family income) PROGRESS categories analysed at outcome: NR Outcomes relating to harms/unintended effects: NR Intervention included strategies to address diversity or disadvantage: NR Economic evaluation: NR
Notes	Funding: this publication was made possible by grant number KL2 RR024130 to J.L.C. from the National Center for Research Resources, a component of the NIH and NIH Road map for medical research, Hellman research grant, and in part by NIH grant DK060617 to M.B.H. No details provided relating to costs of intervention and resources but authors reported it is relatively low cost intervention because it is internet‐based
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐ generated random assignment
Allocation concealment (selection bias)	High risk	Convenience sampling used prior to randomisation; site co‐ordinators helped to identify eligible participants, introducing possibility of bias
Blinding (performance bias and detection bias) All outcomes	Unclear risk	NR
Incomplete outcome data (attrition bias) All outcomes	Low risk	Total loss < 10%; 11% from control and 3% from intervention. No significant differences were found in baseline variables between adolescents who provided follow‐up data and adolescents who were lost to follow‐up
Selective reporting (reporting bias)	Unclear risk	Protocol/trial registration documents were unavailable.
Other bias	Low risk	No other apparent threats to validity