Sussman 1995 TND1 CHS C.

Methods	Country: USA Site: 29 school districts in a 5‐county region of southern California (each district contained 1 Continuation High School (CHS) for students unable to remain in regular high schools for reasons including drug abuse). Project 'Towards No Drug Abuse' (TND) Focus: alcohol, tobacco and drugs Design: cluster RCT Study TND‐1 (CHS): 21 schools continuation schools to assess the impact of TND Study TND‐I (RHS): trial in 26 classes in 3 regular high schools (RHS) to assess whether the TND programme could be used in regular high schools Study TND‐II (CHS): 18 continuation high schools, to compare the relative effectiveness of the TND programme as delivered by health educators or by self instruction (Group 3: point prevalence).
Participants	Baseline: TND‐1 (CHS): 2001 out of a potential 2863; TND‐II CHS trial at baseline: 715 students in 18 continuation high schools; TND‐1 RHS trial at baseline: 679 students in 26 classes in 3 regular high schools. Age: 16.8 years Gender: 44.6% F Ethnicity: 31.6% White, 49.5% Hispanic, 9% African American; 9% other Baseline smoking data: In Continuation high schools in the past month 57% used cigarettes, 64% alcohol, 55% marijuana, 21% stimulants, and 13% hallucinogens. Percentages for comprehensive high schools from overlapping school districts were 24%, 36%, 22%, 2% and 2% respectively.
Interventions	Category: social influences & social competence vs. control Programme deliverer: 9 project staff health educators (trained by the project manager). In the 21 TND‐1 (CHS) schools in the schools + school‐as‐community group, a volunteer staff member taught the school‐as‐community component. Intervention: 9 session health motivation, social skills and decision making curriculum about alcohol, marijuana, cocaine, and hallucinogen use. First 3 sessions motivated youth to listen to subsequent health programming and provided them with effective listening skills (listening, stereotyping, drug use myths, and denial sessions); 2nd set of 3 sessions instructed students in chemical dependency issues and alternative coping strategies (stages of chemical dependency, a talk show on the consequences of drug abuse, and stress coping sessions); 3rd set of 3 sessions encouraged making non‐drug‐use choices (self control skills, taking a moderate perspective, decision‐making, and commitment sessions). After the first year three more sessions were added: a session on the confusion between the effects and causes of marijuana use and consequences on use; a session on tobacco cessation and coping with withdrawal; and a session on coping with feelings of anger that could lead to substance abuse or violence. TND‐1 (CHS) had two interventions: Class only TND Class TND plus a semester‐long school as community component Control: received 'standard care'
Outcomes	Past 30 days smoking: measured on 11 point scale (from 0 to 9 = 1 to 100+ times/month), and measured expired air CO Follow‐up: 5 years
Notes	Quality of intervention delivery: health educators delivered the programme and received 2.5 hrs training for each session. At 1 year the process analysis showed that students attended 2/3 of the drug abuse sessions, with good adherence by educators to planned lesson delivery (99 ‐ 100% in 10/20 lessons); all scores on class control appropriateness of the material were 5 or higher on a 1 to 7 scale. Statistical quality: Was a power computation performed? No Was an intention‐to‐treat analysis performed? Not stated Was a correction for clustering made? Yes Were appropriate statistical methods used? Corrections for estimated ICCs pretest 0.08, then between 0.013 and 0.019. If these correlations had not been included, the true standard errors would have been underestimated and the P values overestimated by 75 ‐ 77% for the cluster (school) sizes. Analysis by ANCOVA. Results only available for TND‐1 (CHS)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"A total of 29 school districts from a five‐county region of southern California were recruited for participation in a procedure approximating random selection. Each of these cooperating districts contained 1 continuation high school. Twenty‐one continuation high schools were selected from that pool for participation in the present study... Selected schools were blocked by estimates of drug use prevalence (based on preliminary student and staff interviews at each school), ethnic composition of the school and community, student enrolment, and standardized achievement scores (based on public data) and were randomly assigned by block to one of three experimental conditions..." Method of randomisation not stated Clusters: schools Cluster constraint: blocked by estimates of drug use prevalence (based on preliminary student and staff interviews at each school), ethnic composition of the school and community, student enrolment, and standardized achievement scores (based on public data). Baseline comparability: no significant differences in drug use and 6 demographic variables when pretest sample compared to sample re‐surveyed after 2 years
Allocation concealment (selection bias)	Unclear risk	No statement
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No statement
Incomplete outcome data (attrition bias) All outcomes	Low risk	TND‐II (CHS) trial: 2863 students in 21 schools were contacted (75% of those enrolled). Pretest data obtained from 2001 (70%). There were no significant differences on 31 items of drug use and psychosocial correlates between the pretest sample and those measured at both pretest and 1yr. Access to 2863 students (75% of those on enrolment lists); Pretest data on 70% (N = 2001) of these; 1 year follow up on 54% (N = 1074). No significant differences on 31 items of drug use and psychosocial correlates between those measured at pretest and 1 year; at 2 years no significant differences in attrition rates across programmes. Sun 2006 provides 4 ‐ 5 year follow‐up: states eligibles = 1867; baseline = 1578, with follow up data at 1 year for 68% (N = 1074), years 2 or 3 for 66% (N = 1047), and at years 4 or 5 for 46% (N = 725 ); at 4 ‐ 5 years no significant differences in attrition rates across programmes.
Selective reporting (reporting bias)	Low risk	No selective reporting