Assessment of generalizability, applicability and predictability (GAP) for evaluating external validity in studies of universal family-based prevention of alcohol misuse in young people: systematic methodological review of randomized controlled trials

The current state of the quality of homeopathic clinical research

Homeopathy is a system of therapeutics that treats disease with highly diluted substances based on the Law of Similars, which holds that "like cures like." Despite widespread use, homeopathy lacks a comprehensive and robust evidence base. We examined the state of homeopathic clinical research by critically assessing the overall quality of peer-reviewed, recently published, English-language, homeopathic clinical research in terms of internal, external, and model validity using standard and homeopathic-specific instruments. Further, we convened an international panel of nine experts in research methods and homeopathy to identify gaps in homeopathic research and prioritize areas for future study. We reviewed 99 clinical research studies targeting a wide range of populations and conditions. Studies were conducted in Western and Asian countries, with the largest number (30 percent) conducted in India. Of the 99 studies reviewed, 85 were controlled trials; 79 of these were randomized. There were many areas where the quality of the studies could be improved. About two-thirds of the 85 controlled trials had either high (42 percent) or unclear (24 percent) risk of bias according to internationally recognized standards for internal validity. Of the 14 observational (cohort) studies, over one-third did not control for important confounders in the outcome analyses. Regarding external validity, adherence was reported in less than a third of studies (n=31). Forty percent of studies (79 % of observational studies) did not report on safety. Regarding model validity, fewer than two-thirds of the studies were consistent with homeopathic principles. Our expert panel was mixed on whether the homeopathic research literature was missing important populations and/or conditions, and they suggested a variety of priority areas. Panelists also expressed a variety of opinions about the types of homeopathy that should be prioritized for future study but also noted that since homeopathic practice differs by country, each country may have different priorities. Panelists agreed with the findings of the literature review that the research literature was at least somewhat deficient in all three types of validity. Although our assessment of validity was [by necessity] based only on what was reported, this assessment suggests the need for both better reporting and higher quality research. They recommended the use of reporting guidelines to improve all types of validity, the identification of exemplar studies to help guide researchers to improve internal validity, and, given the limitations of the instruments available to measure external and model validity, that these instruments be validated and configured to provide summary scores. Finally, substantial discussion addressed the need to bring more research expertise into homeopathic studies, both by better training homeopathic researchers and by collaborating with experienced conventional medicine research groups.

Identification of tools used to assess the external validity of randomized controlled trials in reviews: a systematic review of measurement properties

Background

Internal and external validity are the most relevant components when critically appraising randomized controlled trials (RCTs) for systematic reviews. However, there is no gold standard to assess external validity. This might be related to the heterogeneity of the terminology as well as to unclear evidence of the measurement properties of available tools. The aim of this review was to identify tools to assess the external validity of RCTs. It was further, to evaluate the quality of identified tools and to recommend the use of individual tools to assess the external validity of RCTs in future systematic reviews.

Methods

A two-phase systematic literature search was performed in four databases: PubMed, Scopus, PsycINFO via OVID, and CINAHL via EBSCO. First, tools to assess the external validity of RCTs were identified. Second, studies investigating the measurement properties of these tools were selected. The measurement properties of each included tool were appraised using an adapted version of the COnsensus based Standards for the selection of health Measurement INstruments (COSMIN) guidelines.

Results

38 publications reporting on the development or validation of 28 included tools were included. For 61% (17/28) of the included tools, there was no evidence for measurement properties. For the remaining tools, reliability was the most frequently assessed property. Reliability was judged as “sufficient” for three tools (very low certainty of evidence). Content validity was rated as “sufficient” for one tool (moderate certainty of evidence).

Conclusions

Based on these results, no available tool can be fully recommended to assess the external validity of RCTs in systematic reviews. Several steps are required to overcome the identified difficulties to either adapt and validate available tools or to develop a better suitable tool.

Trial registration

Prospective registration at Open Science Framework (OSF): 10.17605/OSF.IO/PTG4D.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01561-5.

The Mediating Role of Social Support in the Relationship Between Parenting Styles and Adolescent Drug Abuse Identification

Adolescent drug abuse is a social issue of global concern, causing a serious burden of diseases for individuals, families and society. To design effective prevention and intervention strategies for adolescent drug abusers, the predictive factors associated with drug abuse must be quantified and assessed. This study explores the similarities and differences between the parenting styles of adolescent drug abusers and non-drug abusers and applies a structural equation model to analyze the mechanisms involved between parenting styles, social support and adolescent drug abuse identification. Data were derived from adolescent drug abusers (n = 363) and non-drug abusers (n = 229) between the ages of 18 and 35 in China, and the data were collected and analyzed by SPSS 26 and AMOS 24. The results show that parenting styles significantly predict adolescent drug abuse identification, and different parenting styles have different influencing mechanisms, which further indicates that poor parenting styles are a risk factor for adolescent drug abuse. Additionally, social support plays a mediating role between parenting styles and drug abuse identification (χ²/df = 4.52, CFI = 0.939, TLI = 0.914, RMSEA = 0.077, IFI = 0.939, PCFI = 0.671). The specific pathways involved are as follows: Paternal parenting style → Social support → Drug abuse identification and Maternal parenting style → Social support → Drug abuse identification. However, beyond this, the mediation model of social support shows good adaptability and stability between adolescent drug abusers and non-drug abusers. Since parenting styles and social support are important predictors of adolescent drug abuse, the importance of integrating family-social support antidrug programs into adolescent prevention and intervention strategies should be considered.

Motivational Interviewing-based interventions for reducing substance misuse and increasing treatment engagement, retention, and completion in the homeless populations of high-income countries: An equity-focused systematic review and narrative synthesis

AIM

Rising mortality and disease prevalence in the homeless have been largely attributed to addiction disorders. This review aimed to assess whether Motivational Interviewing (MI) is effective in changing substance misuse behaviours in the homeless, specifically: 1. reducing substance misuse; 2. increasing addiction treatment linkage; and 3. whether MI effectiveness varied according to the different levels of social disadvantage within homeless populations.

METHOD

Electronic databases and other sources were searched (to July 2021) for relevant randomized trials and comparative studies. Risk of bias in included studies was evaluated using the Cochrane Risk of Bias tool. A Narrative Synthesis framework was applied to included studies. Moderator variables subgroup analyses were planned a priori. PROSPERO study protocol registration: CRD42019134312 RESULTS: The searches found 1885 records; after application of inclusion criteria n = 11 studies from 30 articles were included in the review, all from the United States. There was a paucity of research regarding MI effectiveness for substance misuse outcomes in homeless populations, with a focus on short-term rather than long-term impacts. Risk of bias was generally low but was high for detection bias in most studies. MI appeared to be more effective overall amongst adult homeless persons, yielding consistently small effects, and alcohol use behaviours seemed to be more amenable to change as a result of MI/MET (Motivational Enhancement Therapy) interventions than drug use ones. Limited evidence with high risk of bias indicated that social gradient may attenuate MI effectiveness within the young homeless population, with no impact in the most disadvantaged.

CONCLUSIONS

The review's mixed findings discourage the use of MI as a stand-alone substance use intervention in homeless populations. Although the review findings did not identify MI effectiveness for substance use according to the external level of social disadvantage faced by homeless persons, this should be a focus for further research.

Effectiveness and safety of the adjunctive use of an internet-based self-management intervention for borderline personality disorder in addition to care as usual: results from a randomised controlled trial

IMPORTANCE

Borderline personality disorder (BPD) is a severe mental disorder that is often inadequately treated.

OBJECTIVE

To determine if adding a self-management intervention to care as usual (CAU) is effective and safe.

DESIGN

Randomised, controlled, rater-blind trial. Duration of treatment and assessments: 12 months.

SETTING

Secondary care, recruited mainly via the internet.

PARTICIPANTS

Patients with BPD and BPD Severity Index (BPDSI) of at least 15.

INTERVENTIONS

CAU by treating psychiatrist and/or psychotherapist alone or adjunctive use of an internet-based self-management intervention that is based on schema therapy (priovi).

MAIN OUTCOME MEASURE

Outcomes were assessed by trained raters. The primary outcome was change in BPDSI. The safety outcome was the number of serious adverse events (SAEs). The primary outcome time point was 12 months after randomisation.

RESULTS

Of 383 participants assessed for eligibility, 204 were included (91.7% female, mean age: 32.4 years; 74% were in psychotherapy and 26% were in psychiatric treatment). The slope of BPDSI change did not differ significantly between groups from baseline to 12 months (F_3,248= 1.857, p=0.14). At 12 months, the within-group effect sizes were d=1.38 (95% CI 1.07 to 1.68) for the intervention group and d=1.02 (95% CI 0.73 to 1.31) for the control group. The between-group effect size was d=0.27 (95% CI 0.00 to 0.55) in the intention-to-treat sample and d=0.39 (95% CI 0.09 to 0.68) for those who used the intervention for at least 3 hours (per-protocol sample). We found no significant differences in SAEs.

CONCLUSIONS

We have not found a significant effect in favour of the intervention. This might be due to the unexpectedly large effect in the group receiving CAU by a psychiatrist and/or psychotherapist alone.

TRIAL REGISTRATION

NCT03418142.

Applicability of pain neuroscience education: Where are we now?

BACKGROUND

Explaining pain to patients through pain neuroscience education (PNE) is currently a widespread treatment studied in the musculoskeletal context. Presently, there is sufficient evidence supporting the effectiveness of PNE in patients with chronic musculoskeletal disorders. However, clinicians must pay attention to the actual possibility to transfer research findings in their specific clinical context.

OBJECTIVE

We analysed the applicability of results of studies focused on PNE, which has not been done previously.

METHODS

A detailed discussion on PNE applicability is provided, starting from published randomized controlled trials that investigated the effectiveness of PNE.

RESULTS

This paper markedly points out the awareness of clinicians on the need for an accurate contextualization when choosing PNE as an intervention in clinical practice.

A conceptual framework for external validity

Evidence-Based Medicine (EBM) encourages clinicians to seek the most reputable evidence. The quality of evidence is organized in a hierarchy in which randomized controlled trials (RCTs) are regarded as least biased. However, RCTs are plagued by poor generalizability, impeding the translation of clinical research to practice. Though the presence of poor external validity is known, the factors that contribute to poor generalizability have not been summarized and placed in a framework. We propose a new population-oriented conceptual framework to facilitate consistent and comprehensive evaluation of generalizability, replicability, and assessment of RCT study quality.

Assessing the applicability of public health intervention evaluations from one setting to another: a methodological study of the usability and usefulness of assessment tools and frameworks

BACKGROUND

Public health interventions can be complicated, complex and context dependent, making the assessment of applicability challenging. Nevertheless, for them to be of use beyond the original study setting, they need to be generalisable to other settings and, crucially, research users need to be able to identify to which contexts it may be applicable. There are many tools with set criteria for assessing generalisability/applicability, yet few seem to be widely used and there is no consensus on which should be used, or when. This methodological study aimed to test these tools to assess how easy they were to use and how useful they appeared to be.

METHODS

We identified tools from an existing review and an update of its search. References were screened on pre-specified criteria. Included tools were tested by using them to assess the applicability of a Swedish weight management intervention to the English context. Researcher assessments and reflections on the usability and utility of the tools were gathered using a standard pro-forma.

RESULTS

Eleven tools were included. Their length, content, style and time required to complete varied. No tool was considered ideal for assessing applicability. Their limitations included unrealistic criteria (requiring unavailable information), a focus on implementation to the neglect of transferability (i.e. little focus on potential effectiveness in the new setting), overly broad criteria (associated with low reliability), and a lack of an explicit focus on how interventions worked (i.e. their mechanisms of action).

CONCLUSION

Tools presenting criteria ready to be used may not be the best method for applicability assessments. They are likely to be either too long or incomplete, too focused on differences and fail to address elements that matter for the specific topic of interest. It is time to progress from developing lists of set criteria that are not widely used in the literature, to creating a new approach to applicability assessment. Focusing on mechanisms of action, rather than solely on characteristics, could be a useful approach, and one that remains underutilised in current tools. New approaches to assessing generalisability that evolve away from checklist style assessments need to be developed, tested, reported and discussed.

External validity, generalisability, applicability and directness: a brief primer

External validity is a construct that attempts to answer the question of whether we can use the results of a study in patients other than those enrolled in the study. External validity consists of two unique underlying concepts, generalisability and applicability. When the concern is about extending the results from a sample to the population from which the sample was drawn, the problem is one of generalisability. When the concern is about using inferences drawn from study participants in the care of specific patients belonging to any population, the problem is one of applicability. Clinicians, guideline developers and policymakers do not struggle with generalisability, but often struggle with applicability. When applicability is deemed to be low for a certain population, certainty in the supporting evidence becomes low due to indirectness.

Steps Towards Alcohol Misuse Prevention Programme (STAMPP): a school- and community-based cluster randomised controlled trial

Background

Alcohol use in young people remains a public health concern, with adverse impacts on outcomes such as health, well-being, education and relationships.

Objectives

To assess the effectiveness and cost-effectiveness of a combined classroom curriculum and parental intervention on self-reported alcohol use [heavy episodic drinking (HED)] and alcohol-related harms (indicators such as getting into fights after drinking, poorer school performance and trouble with friends and family).

Design

A two-arm, cluster randomised controlled trial with schools as the unit of randomisation.

Setting

A total of 105 post-primary schools in Northern Ireland (NI) and Glasgow/Inverclyde Educational Authority areas.

Participants

A total of 12,738 male and female secondary school students (intervention delivered when students were in school year 9 in NI or S2 in Scotland in the academic year 2012–13 and aged 12–13 years) were randomised. Randomisation and baseline (T0) surveys took place when children were in school year 8 or S1. Schools were randomised (1 : 1) by an independent statistician to the Steps Towards Alcohol Misuse Prevention Programme (STAMPP) or to education as normal (EAN). All schools were stratified by free school meal provision. Schools in NI were also stratified by school type (male/female/coeducational).

Interventions

STAMPP combined a school-based alcohol harm reduction curriculum [an adapted version of the School Health and Alcohol Harm Reduction Project (SHAHRP)] and a brief parental intervention designed to support parents in setting family rules around drinking. The classroom component comprised two phases delivered over 2 years, and the parental component comprised a standardised presentation delivered by a trained facilitator at specially arranged parent evenings on school premises. This was followed up a few weeks later by an information leaflet mailed to all intervention pupils’ parents highlighting the main points of the evening.

Main outcome measures

(1) Self-reported HED (defined as self-reported consumption of ≥ 6 units in a single episode in the previous 30 days for male students and ≥ 4.5 units for female students) assessed at 33 months from baseline (T3); and (2) the number of self-reported harms (harms caused by own drinking) assessed at T3.

Data sources

Self-completed pupil questionnaires.

Results

At final follow-up (T3), data were available for 5160 intervention and 5073 control pupils for the HED outcome, and for 5234 intervention and 5146 control pupils for the self-reported harms outcome. The intervention reduced self-reported HED compared with EAN (p < 0.001), but did not reduce self-reported harms associated with own drinking. The odds ratio for the intervention effect on HED was 0.596 (standard error 0.0596, 95% confidence interval 0.490 to 0.725). The mean cost of delivery per school was £818 and the mean cost per individual was £15. There were no clear cost savings in terms of service utilisation associated with the intervention. The process evaluation showed that the classroom component engaged and was enjoyed by pupils, and was valued by teachers. Schools, students, intervention trainers and delivery staff (teachers) were not blind to study condition. Data collection was undertaken by a team of researchers that included the trial manager and research assistants, some of whom were not blinded to study condition. Data analysis of primary and secondary outcomes was undertaken by the trial statistician, who was blinded to the study condition.

Limitations

Although the classroom component was largely delivered as intended, there was very low attendance at the parent/carer event; however, all intervention pupils’ parents/carers received an intervention leaflet.

Conclusions

The results of this trial provide some support for the effectiveness and cost-effectiveness of STAMPP in reducing heavy episodic (binge) drinking, but not in reducing self-reported alcohol-related harms, in young people over a 33-month follow-up period. As there was low uptake of the parental component, it is uncertain whether or not the intervention effect was accounted for by the classroom component alone.

Trial registration

Current Controlled Trials ISRCTN47028486.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full inPublic Health Research; Vol. 5, No. 2. See the NIHR Journals Library website for further project information. The Public Health Agency of NI and Education Boards of Glasgow/Inverclyde provided some intervention costs. Diageo provided funds to print some workbooks. The remaining intervention costs were internally funded.

Correlating eligibility criteria generalizability and adverse events using Big Data for patients and clinical trials

Randomized controlled trials can benefit from proactive assessment of how well their participant selection strategies during the design of eligibility criteria can influence the study generalizability. In this paper, we present a quantitative metric called generalizability index for study traits 2.0 (GIST 2.0) to assess the a priori generalizability (based on population representativeness) of a clinical trial by accounting for the dependencies among multiple eligibility criteria. The metric was evaluated on 16 sepsis trials identified from ClinicalTrials.gov, with their adverse event reports extracted from the trial results sections. The correlation between GIST scores and adverse events was analyzed. We found that the GIST 2.0 score was significantly correlated with total adverse events and serious adverse events (weighted correlation coefficients of 0.825 and 0.709, respectively, with P < 0.01). This study exemplifies the promising use of Big Data in electronic health records and ClinicalTrials.gov for optimizing eligibility criteria design for clinical studies.

Transcultural Adaptation of Questionnaire to Evaluate Drug Use Among Students: The Use of the EU-Dap European Questionnaire in Brazil

BACKGROUND

Social and cultural differences between countries stress the need for adapting existent instruments for adequately comparing epidemiological results. However, there are controversies in literature on how to carry out this process.

OBJECTIVES

This study aimed to describe the process of cultural adaptation and evaluation of the Brazilian Portuguese language of the European Drug Addiction Prevention Trial (EU-Dap) questionnaire to identify alcohol, tobacco, and other drug use among adolescents.

METHODS

The cross-sectional study took place in 16 public schools in three Brazilian cities during the year 2013 in a sample of 2,969 adolescents between the ages of 11 and 16. Operating steps involved analysis of qualitative data collected through student's focus group and field notes by interviewers and quantitative data from test-retest evaluation and nonresponse to item.

RESULTS

The results revealed moderate reliability for the primary outcomes and high levels of nonresponse, mainly in the 2/3 final questions. Focus group provided high-quality information about misconception for the semantic and structure of the questionnaire. Participatory observation helped researchers to tap into the main difficulties of the application context.

CONCLUSIONS

Sociocultural issues related to Brazilian students, the application context, and the structure of the original questionnaire contributed to the unsatisfactory results of the transcultural adaptation process. The results further highlighted the challenge of adapt questionnaires investigating sensitive issues in an age group particularly influenced by educational factors, especially when the countries have different standards of achievement in education.

Trends in alcohol and tobacco use among Brazilian students: 1989 to 2010

OBJECTIVE

To analyze temporal trends of the prevalence of alcohol and tobacco use among Brazilian students.

METHODS

We analyzed data published between 1989 and 2010 from five epidemiological surveys on students from the 6^th to the 12^th grade of public schools from the ten largest state capitals of Brazil. The total sample consisted of 104,104 students and data were collected in classrooms. The same collection tool – a World Health Organization self-reporting questionnaire – and sampling and weighting procedures were used in the five surveys. The Chi-square test for trend was used to compare the prevalence from different years.

RESULTS

The prevalence of alcohol and tobacco use varied among the years and cities studied. Alcohol consumption decreased in the 10 state capitals (p < 0.001) throughout 21 years. Tobacco use also decreased significantly in eight cities (p < 0.001). The highest prevalence of alcohol use was found in the Southeast region in 1993 (72.8%, in Belo Horizonte) and the lowest one in Belem (30.6%) in 2010. The highest past-year prevalence of tobacco use was found in the South region in 1997 (28.0%, in Curitiba) and the lowest one in the Southeast in 2010 (7.8%, in Sao Paulo).

CONCLUSIONS

The decreasing trend in the prevalence of tobacco and alcohol use among students detected all over the Country can be related to the successful and comprehensive Brazilian antitobacco and antialcohol policies. Despite these results, the past-year prevalence of alcohol consumption in the past year remained high in all Brazilian regions.

Affective Self-Regulation Trajectories During Secondary School Predict Substance Use Among Urban Minority Young Adults

This study explored the relationship between trajectories of affective self-regulation skills during secondary school and young adult substance use in a large multi-ethnic, urban sample (N = 995). During secondary school, participants completed a measure of cognitive and behavioral skills used to control negative, unpleasant emotions or perceived stress. As young adults, participants reported on the frequency and quantity of their alcohol, cigarette, and marijuana use in a telephone interview. Controlling for demographic variables, self-regulation did not significantly change over adolescence, although there was significant variation in participants' rates of growth and decline. Lower seventh grade self-regulation and less steep increases in self-regulation were predictive of higher young adult substance use. Male participants had significantly lower initial self-regulation and higher young adult substance use. The results suggest that interventions that build affective self-regulation skills in adolescence may decrease the risk of young adult substance use.

The relationship between mentoring on healthy behaviors and well-being among Israeli youth in boarding schools: a mixed-methods study

Background

Although 10% of Israeli youth live in boarding schools, few studies, except for those focusing on mental health, have examined the well-being of this population subgroup. Thus, the aims of this study were to explore: (1) the prevalence rates of five aspects of well-being (i.e., healthy habits, avoidance of risky behaviors, peer relationships, adult relationships, and school environment) in youth residing at Israeli boarding schools; (2) the relationships between youth well-being and youth perception of their mentor; and (3) the different subgroups of youth with higher rates of risky and healthy behaviors.

Methods

This study used a mixed-methods approach including a quantitative survey of youth (n = 158) to examine the association between youth behaviors and perception of their mentor; and a qualitative study consisting of interviews (n = 15) with boarding school staff to better understand the context of these findings.

Results

Greater proportions of boarding school youth, who had positive perceptions of their mentor (the significant adult or parent surrogate), believed both that their teachers thought they were good students (p < 0.01), and that they themselves were good students (p < 0.01). This finding is supported by the qualitative interviews with mentors. Youth living in a boarding school had very similar healthy habits compared to other youth living in Israel; however, youth in the general population, compared to those in the boarding schools, were eating more sweets (OR = 1.39, 95% CI = 1.02-1.90) and engaging in higher levels of television use (OR = 2.64, 95% CI = 1.97-3.54).

Conclusions

Mentors, the significant adult for youth living in residential education environments, have a major influence on school performance, the major focus of their work; mentors had no impact on healthy behaviors. Overall, there were many similarities in healthy behaviors between youth at boarding schools and youth in the general population; however, the differences in healthy habits seemed related to policies governing the boarding schools as well as its structural elements.

Tranexamic acid for trauma: filling the 'GAP' in evidence

Following findings of the Clinical Randomisation of an Antifibrinolytic in Significant Haemorrhage (CRASH-2) trial, tranexamic acid (TxA) use post trauma is becoming widespread. However, issues of generalisability, applicability and predictability beyond the context of study sites remain unresolved. Internal and external validity of the CRASH-2 trial are currently lacking and therefore incorporation of TxA into routine trauma resuscitation guidelines appears premature. The Pre-hospital Antifibrinolytics for Traumatic Coagulopathy and Haemorrhage (PATCH)-Trauma study is a National Health and Medical Research Council-funded randomised controlled trial of early administration of TxA in severely injured patients likely to have acute traumatic coagulopathy. The study population chosen has high mortality and morbidity and is potentially most likely to benefit from TxA's known mechanisms of action. This and further trials involving appropriate sample populations are required before evidence based guidelines on TxA use during trauma resuscitation can be developed.

Accuracy of Alcohol Use Disorders Identification Test for detecting problem drinking in 18-35 year-olds in England: method comparison study

AIMS

To assess the accuracy of Alcohol Use Disorders Identification Test (AUDIT) scores for problem drinking in males and females aged 18-35 in England.

METHODS

A method comparison study with 420 primary care patients aged 18-35. Test measures were AUDIT and AUDIT-C. Reference standard measures were (a) Time-Line Follow-Back interview for hazardous drinking; World Mental Health Composite International Diagnostic Interview for (b) DSM-IV alcohol abuse, (c) DSM-IV alcohol dependence, (d) DSM-5 alcohol use disorders.

RESULTS

Area under the curve (AUC) was (a) 0.79 (95% CI 0.73-0.85; males) and 0.84 (0.79-0.88; females); (b) 0.62 (0.54-0.72; males) and 0.65 (0.57-0.72; females); (c) 0.77 (0.65-0.87; males) and 0.76 (0.67-0.74; females); (d) 0.70 (0.60-0.78; males) and 0.73 (CI 0.67-0.78; females). Identification of threshold cut-point scores from the AUC was not straightforward. Youden J statistic optimal cut-point scores varied by 4-6 AUDIT scale points for each outcome according to whether sensitivity or specificity were prioritized. Using Bayes' Theorem, the post-test probability of drinking problems changed as AUDIT score increased, according to the slope of the probability curve.

CONCLUSION

The full AUDIT scale showed good or very good accuracy for all outcome measures for males and females, except for alcohol abuse which had sufficient accuracy. In a screening scenario where sensitivity might be prioritized, the optimal cut-point is lower than established AUDIT cut-points of 8+ for men and 6+ for women. Bayes' Theorem to calculate individual probabilities for problem drinking offers an alternative to arbitrary cut-point threshold scores in screening and brief intervention programmes.

Which parenting style is more protective against adolescent substance use? Evidence within the European context

BACKGROUND

This study examines whether authoritative parenting style (characterized by warmth and strictness) is more protective against adolescent substances use than authoritarian (strictness but not warmth), indulgent (warmth but not strictness) and neglectful (neither warmth nor strictness) parenting styles. Emergent research in diverse cultural contexts (mainly Southern European and Latin American countries) questions the fact that authoritative would always be the optimum parenting style.

DESIGN

Multi-factorial MANOVAs.

PARTICIPANTS

A sample of 7718 adolescents, 3774 males (48.9%), 11-19 year-olds (M=14.63 year-olds, SD=1.9 years) from Sweden, United Kingdom, Spain, Portugal, Slovenia, and the Czech Republic.

MEASUREMENTS

Parenting style dimensions (warmth and strictness) and adolescent substance use (alcohol, tobacco, and illegal drugs); additionally another three adolescent outcomes were also measured (self-esteem, school performance and personal disturbances) all of them related in the literature with substance use.

FINDINGS

Both indulgent and authoritative parenting styles were associated with better outcomes than authoritarian and neglectful parenting in all the countries studied. Overall, our results support the idea that in Europe the indulgent parenting style performs as well as the authoritative one since adolescents' scores in the youth outcomes were equal (on substance use and personal disturbances) or even better (on self esteem and school performance) than for authoritative parenting style.

CONCLUSIONS

Parenting styles relate to substance use and other outcomes in the same way in different countries explored. The so-called indulgent parenting style appears to be as good as the authoritative in protecting against substance abuse.

How to assess the external validity and model validity of therapeutic trials: a conceptual approach to systematic review methodology

Background. Evidence rankings do not consider equally internal (IV), external (EV), and model validity (MV) for clinical studies including complementary and alternative medicine/integrative medicine (CAM/IM) research. This paper describe this model and offers an EV assessment tool (EVAT©) for weighing studies according to EV and MV in addition to IV. Methods. An abbreviated systematic review methodology was employed to search, assemble, and evaluate the literature that has been published on EV/MV criteria. Standard databases were searched for keywords relating to EV, MV, and bias-scoring from inception to Jan 2013. Tools identified and concepts described were pooled to assemble a robust tool for evaluating these quality criteria. Results. This study assembled a streamlined, objective tool to incorporate for the evaluation of quality of EV/MV research that is more sensitive to CAM/IM research. Conclusion. Improved reporting on EV can help produce and provide information that will help guide policy makers, public health researchers, and other scientists in their selection, development, and improvement in their research-tested intervention. Overall, clinical studies with high EV have the potential to provide the most useful information about “real-world” consequences of health interventions. It is hoped that this novel tool which considers IV, EV, and MV on equal footing will better guide clinical decision making.

Personalised normative feedback for preventing alcohol misuse in university students: Solomon three-group randomised controlled trial

BACKGROUND

Young people tend to over-estimate peer group drinking levels. Personalised normative feedback (PNF) aims to correct this misperception by providing information about personal drinking levels and patterns compared with norms in similar aged peer groups. PNF is intended to raise motivation for behaviour change and has been highlighted for alcohol misuse prevention by the British Government Behavioural Insight Team. The objective of the trial was to assess the effectiveness of PNF with college students for the prevention of alcohol misuse.

METHODOLOGY

Solomon three-group randomised controlled trial. 1751 students, from 22 British Universities, allocated to a PNF group, a normal control group, or a delayed measurement control group to allow assessment of any measurement effects. PNF was provided by email. Participants completed online questionnaires at baseline, 6- and 12-months (only 12-months for the delayed measurement controls). Drinking behaviour measures were (i) alcohol disorders; (ii) frequency; (iii) typical quantity, (iv) weekly consumption; (v) alcohol-related problems; (vi) perceived drinking norms; and (vii) positive alcohol expectancies. Analyses focused on high-risk drinkers, as well as all students, because of research evidence for the prevention paradox in student drinkers.

PRINCIPAL FINDINGS

Follow-up rates were low, with only 50% and 40% responding at 6- and 12-months, respectively, though comparable to similar European studies. We found no evidence for any systematic attrition bias. Overall, statistical analyses with the high risk sub-sample, and for all students, showed no significant effects of the intervention, at either time-point, in a completed case analysis and a multiple imputation analysis.

CONCLUSIONS

We found no evidence for the effectiveness of PNF for the prevention of alcohol misuse and alcohol-related problems in a UK student population.

REGISTRATION

Controlled-Trials.com ISRCTN30784467.