Woodruff 2007.
| Methods | Country: USA, San Diego County Setting: 14 schools Study design: cluster‐RCT | |
| Participants | Participants: 136 young people volunteering, (I = 77 ; C = 59) Age range: 14‐19 years Criterion for Inclusion: volunteering and consented (parents and teenagers) and smoking ≥ 1 cigarette within the last 30 days Inducements: participants were asked to complete an online survey and paid (sum in brackets) on completion of survey at baseline(USD 5), immediate post intervention (USD 10), 3 months post completion (USD 15) and 12 months post completion (USD 20) Follow‐up method: completion of online survey with reminders Pre‐study smoking status assessment: self‐reported Post‐study smoking status assessment: self‐reported quitting | |
| Interventions | Intervention: web‐based virtual reality world based on sky mall with students as avatars and counsellor present as avatar. Information represented as "shops" and galleries and chat possible as more than one student can be "present". Chat texted based at foot of screen. Students also offered 1‐to‐1 counselling sessions with Smoking Cessation professional Theoretical basis of intervention: MI and responses in virtual world based on SCT Control: asked to complete online surveys with inducements | |
| Outcomes | Self‐reported quitting (7‐day PPA) at 1 year; I = 19, C = 18 Losses to follow‐up: overall 27.2%, I = 32.5%, C = 20.3% | |
| Notes | "Effects of clustering were small" so analysis at individual level | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Cluster‐randomized by school, method not described |
| Allocation concealment (selection bias) | High risk | Students recruited after schools randomized, with different recruitment methods. The 2 conditions did not differ significantly on demographic data, although a significantly greater proportion of intervention subjects were alternative/continuation high school students. The groups differed significantly on several baseline smoking variables |
| Blinding of participants and personnel (performance bias) All outcomes | Unclear risk | Not specified but due to nature of intervention, performance bias unlikely |
| Blinding of outcome assessment (detection bias) All outcomes | High risk | No blinding reported, no biochemical validation used |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Loss to follow‐up was 25% post intervention, 21% for the 3‐month follow‐up survey, and 27% at 12 months. Survey non‐response was higher among intervention participants then among controls (33% vs 15%). All randomized participants included in ITT analysis |
C: control group CBT: cognitive behavioural therapy CO: carbon monoxide cpd: cigarettes per day cpw: cigarettes per week ED: Emergency Department FTND: Fagerstrom Test for Nicotine Dependence h: hour(s) I: intervention group ITT: intention‐to‐treat MI: Motivational Interview/ing NoT: Not on Tobacco NRT: nicotine replacement therapy (m)FTQ: (modified) Fagerstrom tolerance questionnaire OR: odds ratio PPA: point prevalence abstinence RCT: randomized controlled trial SCT: social‐cognitive theory SD: standard deviation SR: sustained release TTM: Transtheoretical model (stages of change)