Sources and Availability of Drug Abuse and Long-Term Effects of Education on Knowledge Aspects of High School Students: A Cluster Randomized Controlled Trial

ERCT Criteria Breakdown

• Level 1 Criteria

  • C

    Class-level RCT

    • Whole schools, not students within a classroom, were allocated to the education and control arms, which satisfies the class-level requirement.
    • "Although randomization was applied at the school level, a significant difference in class level between groups was observed, which may have introduced residual confounding."
    • Relevant Quotes: 1) "A cluster randomized controlled pre-test-post-test trial was conducted in ten randomly selected high schools. Schools were allocated to an education and control groups." (Abstract, p. 314) 2) "The research was conducted in ten randomly selected high school within the study area of these five schools were designated as experimental school and received the educational program while the remaining five school served as control school as and continued with their regular curriculum" (Methods, p. 315) 3) "These high schools were selected from a numbered list located in different geographical sites of Duhok city using the clustering method. In each high school, 3 classes will be selecting 45 students, and all the adolescents from selected classes will be included in this interventional study." (Methods, p. 315) 4) "Although randomization was applied at the school level, a significant difference in class level between groups was observed, which may have introduced residual confounding." (Limitations, p. 318) Detailed Analysis: Criterion C requires that allocation to conditions occur at the class level or a stronger level (school), so that treatment and control students are not intermixed within the same classroom. The paper describes itself as a cluster randomized controlled trial in which whole schools were the allocation unit: five schools formed the education arm and five formed the control arm, and the Limitations section states explicitly that "randomization was applied at the school level." The description of the randomisation mechanism is thin - no random number generator, sequence generation, or concealment procedure is reported, and the wording mixes random selection of schools with allocation of schools to arms. However, the unit of allocation is unambiguously the school (an entire cluster of three classes per school), which is stronger than the class level and eliminates within-class contamination. Under the ERCT rule that a school-level RCT automatically satisfies the weaker class-level requirement, this criterion is satisfied. Criterion C is met because entire schools (each containing three whole classes) rather than individual students were allocated to the education and control conditions.
  • E

    Exam-based Assessment

    • Outcomes came from a custom questionnaire the authors assembled from the literature, not from any recognised standardised exam.
    • "Knowledge regarding drug abuse was assessed using a structured, pre-validated questionnaire developed from existing literature."
    • Relevant Quotes: 1) "Knowledge regarding drug abuse was assessed using a structured, pre-validated questionnaire developed from existing literature. The questionnaire measured students' awareness of type of drug, associated risks, and prevention strategies." (Methods, p. 315) 2) "A pilot study was conducted on small group of students (n=45) from school not included in the main study to test the clarity, reliability and validity of the question and the feasibility of the intervention. Feedback from the pilot informed minor revision to the questionnaire and improved the delivery of the education program." (Methods, p. 315) 3) "A post-test was administered to both groups three month after the intervention using the same questionnaire to assess changes in knowledge." (Methods, p. 315) 4) "Knowledge score Mean (SD) 3.23 (1.78) 6.64 (0.96) <0.0001" (Table 4, p. 322) Detailed Analysis: Criterion E requires that outcomes be measured with a standardised, widely recognised exam rather than an instrument built by the researchers for the study. The outcome instrument here is a self-report knowledge questionnaire "developed from existing literature" by the authors, revised after their own pilot study. No name of any national, state-wide, or internationally recognised test is given, and no published validity or reliability statistics from an external testing body are cited - only an in-house pilot on 45 students. The items reported in Tables 3 and 4 ("Alcohol as a drug abuse", "Smoking as drug abuse", "Reasons for using drugs", "Intend to use drugs") are bespoke awareness and intention items tightly aligned with the PowerPoint content delivered to the education group, which is exactly the alignment bias the criterion is designed to exclude. No school examination, curriculum test, or standardised achievement measure of any kind was administered. Criterion E is not met because outcomes were measured with a researcher-assembled questionnaire rather than a recognised standardised exam.
  • T

    Term Duration

    • The post-test was administered three months after the intervention, which reaches the one-term follow-up requirement.
    • "A post-test was administered to both groups three month after the intervention using the same questionnaire to assess changes in knowledge."
    • Relevant Quotes: 1) "The pre-test was administered to both experimental and control groups at baseline. The educational program was delivered to experimental group using Power point presentation that included information on drug type, consequences of drug abuse, prevention methods and strategies for resisting peer pressure." (Methods, p. 315) 2) "A post-test was administered to both groups three month after the intervention using the same questionnaire to assess changes in knowledge." (Methods, p. 315) 3) "At three-month follow-up, the education group showed significantly higher knowledge across all domains" (Abstract, p. 314) 4) "Additionally, the three-month follow-up period enabled assessment of sustained knowledge changes rather than immediate post-intervention effects." (Strengths, p. 318) Detailed Analysis: Criterion T requires that the primary outcome be measured at least one full academic term (roughly three to four months) after the intervention begins, while explicitly allowing the intervention itself to be short provided the follow-up tracking reaches term length. The intervention here was brief - PowerPoint-based sessions - but the paper states in three separate places that the post-test was administered three months after the intervention, and the Strengths section frames this as deliberate follow-up designed to capture sustained rather than immediate effects. A three-month interval from intervention start to outcome measurement corresponds to approximately one academic term. No exact calendar dates are given, which weakens the documentation, but the interval is stated consistently and unambiguously as three months and satisfies the minimum the criterion sets. Criterion T is met because the primary outcome was measured three months after the intervention, which corresponds to at least one full academic term.
  • D

    Documented Control Group

    • The control arm's size, demographics, baseline knowledge, and business-as-usual condition are fully tabulated and described.
    • "The control group did not receive any intervention during this period."
    • Relevant Quotes: 1) "the remaining five school served as control school as and continued with their regular curriculum" (Methods, p. 315) 2) "The control group did not receive any intervention during this period." (Methods, p. 315) 3) "Table 1: General characteristics of the high school students of the control and education groups ... Control (n=225) ... Age Mean (SD) 16.96 (1.18) ... Gender Male 107 (47.56) Female 118 (52.44) ... Living site Rural 15 (6.67) Urban 210 (93.33) ... Socioeconomic statues Low 10 (4.44) Moderate 191 (84.89) High 24 (10.67)" (Table 1, p. 320) 4) "The study found that the education and control groups were similar in age (p=0.6258), gender (p=0.050), living site (p=0.2081), socioeconomic statues (p=0.2263), family members (p=0.1542, father's education (p=0.2365), mother's education (p=0.0479), using drugs in family/friends (p=0.4819). But there was significant deference between education and control groups regrading classes (p=0.0082)." (Results, p. 316) 5) "None of the items reached the typical threshold for statistical significance (p > 0.05)." (Results, Table 3 commentary, p. 316) Detailed Analysis: Criterion D requires the control group to be documented with demographics, baseline performance, and a statement of what treatment it received. All three elements are present. The control arm size is given (n=225, drawn from five schools), Table 1 reports its age, gender, living site, class level, socioeconomic status, family size, parental education, and family or peer drug use, and Table 3 reports its item-by-item baseline knowledge alongside the education group with p-values. The paper also states the condition placed on the control group: it "continued with their regular curriculum" and "did not receive any intervention during this period." The authors additionally disclose a baseline imbalance in class level (p=0.0082) and flag it in the Limitations, which is a further sign of adequate documentation rather than a documentation failure. Criterion D is met because the control group's size, demographics, baseline knowledge, and business-as-usual condition are all reported in detail.

• Level 2 Criteria

  • S

    School-level RCT

    • Ten whole high schools, five per arm, were the unit of allocation, which the Limitations section confirms as school-level randomisation.
    • "A cluster randomized controlled pre-test-post-test trial was conducted in ten randomly selected high schools. Schools were allocated to an education and control groups."
    • Relevant Quotes: 1) "A cluster randomized controlled pre-test-post-test trial was conducted in ten randomly selected high schools. Schools were allocated to an education and control groups." (Abstract, p. 314) 2) "The research was conducted in ten randomly selected high school within the study area of these five schools were designated as experimental school and received the educational program while the remaining five school served as control school" (Methods, p. 315) 3) "Although randomization was applied at the school level, a significant difference in class level between groups was observed, which may have introduced residual confounding." (Limitations, p. 318) 4) "The use of multistage cluster sampling across multiple high schools in different geographical areas of Duhok City improved the representativeness of the sample" (Strengths, p. 318) Detailed Analysis: Criterion S requires that whole schools, rather than classes or students within schools, be the randomised unit. The paper reports ten high schools in Duhok City, with five allocated to the education arm and five to the control arm, and the Limitations section states directly that "randomization was applied at the school level." The number of schools (10) and the number of students per school (three classes of roughly 45 students) are given. The mechanism of allocation is not described - there is no account of sequence generation, stratification, or who performed the allocation, and the phrasing "were designated as experimental school" leaves ambiguity about whether allocation to arm was itself random or was a designation made after random selection of the ten schools. Weighed against this, the paper labels itself a cluster RCT, states school-level randomisation explicitly in its own Limitations, and consistently reports the school as the allocation unit throughout. On the evidence quoted, the school-level requirement is satisfied even though the reporting quality is poor. Criterion S is met because the paper states that randomisation was applied at the school level across ten high schools, five per arm.
  • I

    Independent Conduct

    • The same two authors designed, delivered, measured, and analysed the intervention with no external or third-party evaluation.
    • "A - Study Design, B - Data Collection, C - Statistical Analysis, D - Data Interpretation, E - Manuscript Preparation, F - Literature Search"
    • Relevant Quotes: 1) "Sarhang Qadir Surchi 1, A, C, F and Ramadhan Hameed Teeli 2, B, D, E, F ... A - Study Design, B - Data Collection, C - Statistical Analysis, D - Data Interpretation, E - Manuscript Preparation, F - Literature Search" (Title page, p. 314) 2) "The educational program was delivered to experimental group using Power point presentation that included information on drug type, consequences of drug abuse, prevention methods and strategies for resisting peer pressure." (Methods, p. 315) 3) "A pilot study was conducted on small group of students (n=45) from school not included in the main study to test the clarity, reliability and validity of the question and the feasibility of the intervention. Feedback from the pilot informed minor revision to the questionnaire and improved the delivery of the education program." (Methods, p. 315) 4) "Source of support: Nil." / "Conflict of interest: None" (Title page, p. 314) 5) "Scientific Research Ethical Committee at the University of Erbil, College of Nursing has approved the study to be conducted in reference number 28082024-7-3." (Ethical Considerations, p. 316) Detailed Analysis: Criterion I requires that the evaluation be carried out independently of those who designed the intervention, or that credible third-party oversight of data collection and analysis be documented. The author contribution codes show that the two authors between them performed study design (A), data collection (B), statistical analysis (C), and data interpretation (D). The same authors also built the educational program - they piloted it and used the pilot feedback to improve "the delivery of the education program" - and they built the outcome questionnaire. There is no external evaluator, no independent data collection agency, no blinded assessors, and no statement anywhere separating the intervention developers from the evaluators. The only external body mentioned is the institutional ethics committee, which approves but does not conduct or oversee the trial and therefore does not qualify as independent evaluation under this criterion. This is the classic single-team design-deliver-measure configuration the criterion is intended to exclude. Criterion I is not met because the same two authors designed the educational program, delivered it, collected the data, and analysed the results with no independent evaluator.
  • Y

    Year Duration

    • The only follow-up was three months after the intervention, far short of 75% of an academic year.
    • "Additionally, the three-month follow-up period enabled assessment of sustained knowledge changes rather than immediate post-intervention effects."
    • Relevant Quotes: 1) "A post-test was administered to both groups three month after the intervention using the same questionnaire to assess changes in knowledge." (Methods, p. 315) 2) "At three-month follow-up, the education group showed significantly higher knowledge across all domains" (Abstract, p. 314) 3) "Additionally, the three-month follow-up period enabled assessment of sustained knowledge changes rather than immediate post-intervention effects." (Strengths, p. 318) 4) "The intervention focused primarily on knowledge outcomes and did not assess behavioral changes or long-term prevention outcomes related to drug use." (Limitations, p. 318) Detailed Analysis: Criterion Y requires outcomes to be measured at least 75% of an academic year - roughly seven months or more - after the intervention begins. The only follow-up interval reported anywhere in this paper is three months, described consistently in the abstract, methods, and strengths sections. Three months is approximately one third of a nine to ten month academic year, far short of the 75% threshold, and the shortfall is not minor. The authors themselves concede in the Limitations that the study "did not assess behavioral changes or long-term prevention outcomes related to drug use," confirming that no longer tracking window exists. Despite the paper's title referring to "Long-Term Effects", the operational follow-up is a single three-month post-test. Criterion Y is not met because the maximum tracking interval was three months, well below 75% of an academic year.
  • B

    Balanced Control Group

    • The added PowerPoint education sessions are themselves the treatment variable tested against a business-as-usual curriculum, so the passive control is permitted by design.
    • "Therefore, the present study aims to evaluate the effectiveness of a school-based educational intervention in improving knowledge related to substance abuse among high school students."
    • Relevant Quotes: 1) "The educational program was delivered to experimental group using Power point presentation that included information on drug type, consequences of drug abuse, prevention methods and strategies for resisting peer pressure. The control group did not receive any intervention during this period." (Methods, p. 315) 2) "the remaining five school served as control school as and continued with their regular curriculum" (Methods, p. 315) 3) "Therefore, the present study aims to evaluate the effectiveness of a school-based educational intervention in improving knowledge related to substance abuse among high school students." (Introduction, p. 315) 4) "Finally, the educational intervention was delivered using a single method (PowerPoint-based sessions), which may not capture the full potential of more interactive or multimodal educational approaches." (Limitations, pp. 318-319) Detailed Analysis: Applying the criterion B decision tree. First, are extra resources present? Yes - the education arm received PowerPoint-based instructional sessions covering drug types, consequences, prevention methods, and peer-pressure resistance, which is instructional time and material the control arm did not receive. The control arm "continued with their regular curriculum" and "did not receive any intervention during this period," so there is no matching activity, no active control, and no compensatory time. Second, is the difference negligible? The added dosage is not quantified - the paper never reports the number of sessions or minutes - but a single-method PowerPoint delivery is modest rather than clearly trivial, so this branch cannot be relied on. Third, are the extra resources the treatment variable? Yes. The stated aim is "to evaluate the effectiveness of a school-based educational intervention in improving knowledge related to substance abuse." The additional instructional session is not a separable add-on bolted on to some other manipulation; it is precisely and entirely the thing being tested, against a business-as-usual regular curriculum baseline. Under the standard's explicit allowance, a control group may remain business-as-usual when the added educational input is itself the treatment variable, so the decision tree returns met at this branch. It should be recorded that this is a passive rather than an active control: the control schools received no substitute activity of equivalent duration, so any Hawthorne or attention effect is fully confounded with the programme content. That weakens interpretation but does not, under the ERCT rule, break criterion B. Criterion B is met because the added educational sessions are the explicit treatment variable being tested against a business-as-usual regular curriculum control.

• Level 3 Criteria

  • R

    Reproduced

    • Internet searching found no independent replication of this specific trial, which was published only in March 2026.
    • "evidence regarding patterns of drug abuse and the effectiveness of educational interventions in the Kurdistan Region remains limited"
    • Relevant Quotes: 1) "evidence regarding patterns of drug abuse and the effectiveness of educational interventions in the Kurdistan Region remains limited" (Abstract, p. 314) 2) "However, evidence on structured substance abuse education programs remains limited in certain contexts, including Iraq." (Introduction, p. 315) 3) "Mahmood N, Othman S, Al-Tawil N, Al-Hadithi T. Impact of an education intervention on knowledge of high school students concerning substance use in Kurdistan Region-Iraq: a quasi-experimental study. PLoS One. 2018;13(10):e0206063." (Reference 10, p. 319) 4) "Vigna-Taglianti F, van der Kreeft P, et al. Effects of the "Unplugged" school-based substance use prevention program in Nigeria: a cluster randomized controlled trial. Drug Alcohol Depend. 2021;228:108966. doi:10.1016/j.drugalcdep.2021.108966" (Reference 19, p. 320) Detailed Analysis: Criterion R requires that this specific study be independently replicated by a different research team in a different context, published in a peer-reviewed journal. The paper is dated March 2026 (received 1 March 2026, available online 30 March 2026) and reports a novel trial in Duhok City; it does not describe any replication of itself. Internet verification was carried out for this check. Searches on the DOI (10.25258/ijddt.16.29s.39), the full title, and both author names returned only the article itself (the IJDDT issue listing and the publisher PDF mirror) and unrelated substance-use literature. No paper by any other research team was found that references this trial, reproduces its PowerPoint-based programme, reuses its questionnaire, or repeats its design in another context. No verbatim quote from any replication study can be provided because no such study exists. The cited literature contains related but non-replicating work: Mahmood et al. (2018) is an earlier quasi-experimental study in the same region, published eight years before this trial and therefore incapable of replicating it, and the Unplugged trials in Nigeria (Vigna-Taglianti et al., 2021) and Croatia (Stefan et al., 2018) evaluate a different, manualised prevention curriculum. Neither reproduces this study's programme, its instrument, or its design. Criterion R is not met because internet searching found no independent replication of this specific trial by any other research team.
  • A

    All-subject Exams

    • Criterion E fails and only drug-abuse knowledge was measured, with no school subject assessed at all.
    • "Knowledge of drug types, availability, risks, consequences, and prevention was assessed."
    • Relevant Quotes: 1) "Knowledge of drug types, availability, risks, consequences, and prevention was assessed." (Abstract, p. 314) 2) "The questionnaire measured students' awareness of type of drug, associated risks, and prevention strategies." (Methods, p. 315) 3) "Table 4: Comparisons of knowledge contents between control and education after education in all students ... Alcohol as a drug abuse ... The effect of drugs on feelings ... Relation of drug addiction to illegal drugs ... Problematic effects of drugs ... Intend to use drugs ... Smoking as drug abuse ... Means of narcotic substances ... Reasons for using drugs ... Knowledge score" (Table 4, p. 322) 4) "The intervention focused primarily on knowledge outcomes and did not assess behavioral changes or long-term prevention outcomes related to drug use." (Limitations, p. 318) Detailed Analysis: Criterion A requires that all main school subjects be assessed using standardised exams, and it explicitly fails whenever criterion E fails. Criterion E is not met here, because the sole outcome instrument is a researcher-assembled questionnaire, so criterion A fails on that prerequisite alone. Independently of the prerequisite, the substantive requirement is also unmet. The only domain measured is drug-abuse knowledge and intention. No academic subject - not mathematics, not the language of instruction, not science, not social studies - was assessed at any point, so there is no way to detect whether time diverted to the programme harmed performance in the taught curriculum. The authors offer no vocational or specialisation rationale that would qualify for the exception. Criterion A is not met because criterion E fails and because only drug-abuse knowledge, not any school subject, was assessed.
  • G

    Graduation Tracking

    • Criterion Y fails, measurement stopped at a three-month post-test, and no follow-up publication tracking the cohort to graduation was found.
    • "The intervention focused primarily on knowledge outcomes and did not assess behavioral changes or long-term prevention outcomes related to drug use."
    • Relevant Quotes: 1) "A post-test was administered to both groups three month after the intervention using the same questionnaire to assess changes in knowledge." (Methods, p. 315) 2) "The intervention focused primarily on knowledge outcomes and did not assess behavioral changes or long-term prevention outcomes related to drug use." (Limitations, p. 318) 3) "Inclusion included students currently enrolled in the selected schools, aged between 16 and 20 years, and willing to participate in both pre- and post- tests." (Methods, p. 315) 4) "Regular monitoring and evaluation using pre- and post-intervention assessments are essential to assess effectiveness and guide improvements." (Recommendations, p. 319) Detailed Analysis: Criterion G requires tracking of participants through to graduation from their educational stage, and it fails automatically whenever criterion Y fails. Criterion Y is not met here, so criterion G fails on that prerequisite. The substantive evidence agrees. Measurement stopped at a single three-month post-test. Table 1 shows the cohort spans 4th, 5th, and 6th classes, so a substantial share of participants had one or two years remaining before completing secondary school, yet no end-of-school data, examination results, or graduation records were collected. The authors concede they did not assess long-term outcomes, and they frame further monitoring as a recommendation for future work rather than something they undertook. Internet verification was carried out for this check, as graduation tracking can appear in later papers by the same authors. Searches on both author names (Sarhang Qadir Surchi and Ramadhan Hameed Teeli), their Hawler Medical University affiliation, and the trial title returned no subsequent publication following this Duhok cohort to graduation or to any later time point. No follow-up paper was located, so no verbatim quote from one can be provided; none is invented here. Criterion G is not met because tracking ended at a three-month post-test and no follow-up publication tracking this cohort to graduation could be found.
  • P

    Pre-Registered

    • The paper reports institutional ethics approval only, with no trial registration number, registry, or pre-registered protocol, and none was found in public registries.
    • Relevant Quotes: 1) "Scientific Research Ethical Committee at the University of Erbil, College of Nursing has approved the study to be conducted in reference number 28082024-7-3." (Ethical Considerations, p. 316) 2) "Source of support: Nil." / "Conflict of interest: None" (Title page, p. 314) 3) "The study design is a randomized controlled trial -experimental with pre-test and post-test." (Methods, p. 315) 4) "The statistical calculations were performed using JMP, Version 18.0. SAS Institute Inc., Cary, NC, 1989-2023." (Statistical Analyses, p. 316) Detailed Analysis: Criterion P requires a pre-registered protocol on a public registry, dated before data collection began, covering hypotheses, methods, and planned analyses. The paper contains no registry name, no trial registration number, no registration date, and no link to any protocol or statistical analysis plan. Reading the full text for ClinicalTrials.gov, ISRCTN, PACTR, IRCT, ANZCTR, or any equivalent registry yields nothing. Internet verification was carried out for this check. Registry-directed searches combining the trial location (Duhok), design (cluster randomised school-based drug abuse education), and the author names returned no matching registration in any public trial registry. There is therefore nothing to date-check against the start of data collection. The only regulatory reference is institutional ethics approval, number 28082024-7-3, from the College of Nursing ethics committee. Ethics approval is a distinct process from public pre-registration: it does not publish the hypotheses or the analysis plan and therefore does not protect against selective reporting, which is what this criterion exists to guard against. The absence is particularly consequential given the many outcome items reported across Tables 2 to 5 with no designated primary outcome. Criterion P is not met because no trial registration or pre-registered protocol of any kind is referenced in the paper or discoverable in public registries.