Article
Health Care Sciences & Services
Qiukui Hao, Ya Gao, Yunli Zhao, M. Hassan Murad, Reem Mustafa, Mohammed T. Ansari, Holger J. Schunemann, David M. Rind, Romina Brignardello-Petersen, Gordon Guyatt
Summary: This study describes the important role of considering external evidence in determining the certainty of evidence, using a network meta-analysis as an example. Through discussions and formal logical analysis, the certainty of network estimates was evaluated.
JOURNAL OF CLINICAL EPIDEMIOLOGY
(2023)
Article
Health Care Sciences & Services
Romina Brignardello-Petersen, Gordon H. Guyatt, Reem A. Mustafa, Derek K. Chu, Monica Hultcrantz, Holger J. Schuenemann, George Tomlinson
Summary: This article introduces the GRADE guidance for assessing imprecision in network meta-analysis. Reviewers should consider 95% confidence or credible interval, and optimal information size when rating the certainty of the evidence. If certain thresholds are crossed, certainty rating should be downgraded.
JOURNAL OF CLINICAL EPIDEMIOLOGY
(2021)
Article
Mathematical & Computational Biology
Ming-Chieh Shih, Yu-Kang Tu
Summary: This study aims to show that evidence is not properly split into direct and indirect evidence in current inconsistency models, and proposes a novel approach based on the principle of independence between direct and indirect evidence. Current models for direct-indirect evidence inconsistency can potentially lead to misleading conclusions, while the proposed evidence-splitting model assigns satisfying weights and satisfies the principle of independence. The evidence-splitting model could be a valuable tool for assessing inconsistency in NMA and evaluating the quality of its evidence.
RESEARCH SYNTHESIS METHODS
(2021)
Article
Health Care Sciences & Services
Silvia Minozzi, Gian Paolo Morgano, Maria Luisa Scattoni, Michela Cinquini, Laura Amato
Summary: This article discusses two alternative approaches for complementing direct evidence from RCTs when considered insufficient by guideline panels. Panel members were tasked with determining the sufficiency of direct evidence and selecting an alternative method on a case-by-case basis, which presented challenges in both organization and methodology. It is suggested to establish research protocols early on to define criteria for expanding the evidence base, considering factors like certainty, clinical applicability, feasibility, and conflict of interest.
JOURNAL OF CLINICAL EPIDEMIOLOGY
(2021)
Article
Health Care Sciences & Services
Jadbinder Seehra, Kristina Bertl, Clovis Mariano Faggion, Nikolaos Pandis
Summary: This meta-epidemiological study aimed to evaluate the certainty of evidence in oral health by examining the GRADE ratings in Cochrane systematic reviews. The results showed that the certainty of evidence for all outcomes examined was primarily rated as very low or low. Factors such as study limitations and imprecision were the main reasons for downgrading confidence in the evidence. Overall, the study found that the odds of achieving a moderate/high GRADE rating were higher for primary outcomes compared to secondary outcomes, and that the certainty of evidence tended to decrease over the years 2010-2021.
JOURNAL OF CLINICAL EPIDEMIOLOGY
(2022)
Review
Infectious Diseases
Ya Gao, Yunli Zhao, Gordon Guyatt, Robert Fowler, Richard Kojan, Long Ge, Jinhui Tian, Qiukui Hao
Summary: Specific treatments targeting Ebola virus are crucial in managing Ebola virus disease. The systematic review and network meta-analysis showed that REGN-EB3 and mAb114 were more effective in reducing mortality compared to other treatments or standard care.
Review
Clinical Neurology
Thangaraj Abiramalatha, Tapas Bandyopadhyay, Viraraghavan Vadakkencherry Ramaswamy, Nasreen Banu Shaik, Sivam Thanigainathan, Abdul Kareem Pullattayil, Prakash Amboiram
Summary: The study found that the certainty of evidence for most risk factors associated with periventricular leukomalacia in preterm neonates is low. Future research should focus on genetic predisposition and defective placentation in the mother-placental-fetal triad.
PEDIATRIC NEUROLOGY
(2021)
Article
Health Care Sciences & Services
Linan Zeng, Romina Brignardello-Petersen, Monica Hultcrantz, Reed A. C. Siemieniuk, Nancy Santesso, Gregory Traversy, Ariel Izcovich, Behnam Sadeghirad, Paul E. Alexander, Tahira Devji, Bram Rochwerg, Mohammad H. Murad, Rebecca Morgan, Robin Christensen, Holger J. Schunemann, Gordon H. Guyatt
Summary: This study provides practical principles and examples to help GRADE users make optimal choices regarding their ratings of certainty of evidence using a minimally or partially contextualized approach. Systematic review and health technology assessment authors need to clarify their target of certainty rating, which depends on contextualization, thresholds, and estimate location. GRADE offers guidance for specifying the target of certainty of evidence rating.
JOURNAL OF CLINICAL EPIDEMIOLOGY
(2021)
Article
Health Care Sciences & Services
Carlos A. Cuello-Garcia, Nancy Santesso, Rebecca L. Morgan, Jos Verbeek, Kris Thayer, Mohammed T. Ansari, Joerg Meerpohl, Lukas Schwingshackl, Srinivasa Vittal Katikireddi, Jan L. Brozek, Barnaby Reeves, Mohammad H. Murad, Maicon Falavigna, Reem Mustafa, Deborah L. Regidor, Paul Elias Alexander, Paul Garner, Elie A. Akl, Gordon Guyatt, Holger J. Schunemann
Summary: This article provides guidance on when to search for and include randomized controlled studies and non-randomized studies of interventions in systematic reviews to inform health recommendations.
JOURNAL OF CLINICAL EPIDEMIOLOGY
(2022)
Review
Rehabilitation
Silvia Gianola, Silvia Bargeri, Giulia Nembrini, Arianna Varvello, Carole Lunny, Greta Castellini
Summary: A meta-research study found that about one-third of systematic reviews in the field of rehabilitation assess the certainty of evidence using the GRADE system. Most reviews presented the GRADE assessment transparently, but some had shortcomings in reporting. Journal editors and funders should encourage the use of the GRADE system and require authors to pre-define the GRADE assessment in registered and/or published protocols.
ARCHIVES OF PHYSICAL MEDICINE AND REHABILITATION
(2023)
Review
Ophthalmology
Sharon Ho, Angelica Ly, Kyoko Ohno-Matsui, Michael Kalloniatis, Gordon S. Doig
Summary: The purpose of this study was to evaluate the diagnostic accuracy of OCTA and OCT for mCNV through a systematic review and meta-analysis. FA was considered as the reference standard. The test accuracy of OCTA and/or OCT for diagnosing mCNV was assessed by searching studies in PUBMED and EMBASE databases. Pooled estimates of test accuracy were obtained using a bivariate model.
Article
Health Care Sciences & Services
Sarah S. Werner, Nadine Binder, Ingrid Toews, Holger J. Schunemann, Joerg J. Meerpohl, Lukas Schwingshackl
Summary: The study found that the use of the GRADE approach in nutrition systematic reviews is common, but there are still a proportion of evidence ratings that are low. Evidence certainty is mostly downgraded due to factors such as risk of bias and imprecision. The study suggests strengthening the acceptance and knowledge of the GRADE methodology in nutrition evidence synthesis.
JOURNAL OF CLINICAL EPIDEMIOLOGY
(2021)
Article
Health Care Sciences & Services
Bada Yang, Reem A. Mustafa, Patrick M. Bossuyt, Jan Brozek, Monica Hultcrantz, Mariska M. G. Leeflang, Holger J. Schunemann, Miranda W. Langendam
Summary: This article provides GRADE guidance on assessing the certainty of evidence for comparative test accuracy questions, extending existing guidance for assessing test accuracy to scenarios with multiple index tests. It highlights additional considerations needed for rating certainty in comparisons of test accuracy and emphasizes the need for distinct approaches for comparative test accuracy studies and indirect comparisons between studies.
JOURNAL OF CLINICAL EPIDEMIOLOGY
(2021)
Article
Multidisciplinary Sciences
Zhengping Chang, Jianguo Xu, Yu Qin, Qingyong Zheng, Liang Zhao, Yunfang Wang, Yan Zhang
Summary: Type 2 diabetes mellitus (T2DM) is a significant global burden, and this protocol aims to provide a comprehensive overview of systematic reviews based on network meta-analysis of anti-hyperglycemic agents for T2DM patients. The primary outcomes will be HbA1c and FPG, and the quality of included reviews will be assessed using the AMSTAR-2 tool and GRADE. The results will be disseminated through publications, conferences, clinical networks, and consumer networks.
Article
Health Care Sciences & Services
Lukas Schwingshackl, Blin Nagavci, Julia Stadelmaier, Sarah S. Werner, Carlos A. Cuello Garcia, Holger J. Schuenemann, Joerg J. Meerpohl
Summary: The study evaluated the impact of pooling evidence from randomized controlled trials and cohort studies on certainty-of-evidence. Pooling both types of evidence reduced the amount of very-low and low certainty ratings, but proper guidance is needed before considering this approach.
JOURNAL OF CLINICAL EPIDEMIOLOGY
(2022)
Article
Medicine, General & Internal
Omar Dewidar, Tamara Lotfi, Miranda W. Langendam, Elena Parmelli, Zuleika Saz Parkinson, Karla Solo, Derek K. Chu, Joseph L. Mathew, Elie A. Akl, Romina Brignardello-Petersen, Reem A. Mustafa, Lorenzo Moja, Alfonso Iorio, Yuan Chi, Carlos Canelo-Aybar, Tamara Kredo, Justine Karpusheff, Alexis F. Turgeon, Pablo Alonso-Coello, Wojtek Wiercioch, Annette Gerritsen, Miloslav Klugar, Maria Ximena Rojas, Peter Tugwell, Vivian Andrea Welch, Kevin Pottie, Zachary Munn, Robby Nieuwlaat, Nathan Ford, Adrienne Stevens, Joanne Khabsa, Zil Nasir, Grigorios Leontiadis, Joerg Meerpohl, Thomas Piggott, Amir Qaseem, Micayla Matthews, Holger J. Schunemann
Summary: An evidence-based approach is the gold standard for health decision-making, but the use of the GRADE approach for strong recommendations is inappropriate in cases where the evidence is indirect. We found widespread use of GPS in COVID-19 related recommendations, but guideline developers failed to transparently report their development process. We propose improvements to the operationalization of the GRADE guidance for GPS, including a structured process and standardized reporting.
BMJ EVIDENCE-BASED MEDICINE
(2023)
Article
Allergy
Bernardo Sousa-Pinto, Holger J. Schunemann, Ana Sa-Sousa, Rafael Jose Vieira, Rita Amaral, Josep M. Anto, Ludger Klimek, Wienczyslawa Czarlewski, Joaquim Mullol, Oliver Pfaar, Anna Bedbrook, Luisa Brussino, Violeta Kvedariene, Desiree E. Larenas-Linnemann, Yoshitaka Okamoto, Maria Teresa Ventura, Ioana Agache, Ignacio J. Ansotegui, Karl C. Bergmann, Sinthia Bosnic-Anticevich, G. Walter Canonica, Victoria Cardona, Pedro Carreiro-Martins, Thomas Casale, Lorenzo Cecchi, Tomas Chivato, Derek K. Chu, Cemal Cingi, Elisio M. Costa, Alvaro A. Cruz, Stefano Del Giacco, Philippe Devillier, Patrik Eklund, Wytske J. Fokkens, Bilun Gemicioglu, Tari Haahtela, Juan Carlos Ivancevich, Zhanat Ispayeva, Marek Jutel, Piotr Kuna, Igor Kaidashev, Musa Khaitov, Helga Kraxner, Daniel Laune, Brian Lipworth, Renaud Louis, Michael Makris, Riccardo Monti, Mario Morais-Almeida, Ralph Mosges, Marek Niedoszytko, Nikolaos G. Papadopoulos, Vincenzo Patella, Nhan Pham-Thi, Frederico S. Regateiro, Sietze Reitsma, Philip W. Rouadi, Boleslaw Samolinski, Aziz Sheikh, Milan Sova, Ana Todo-Bom, Luis Taborda-Barata, Sanna Toppila-Salmi, Joaquin Sastre, Ioanna Tsiligianni, Arunas Valiulis, Olivier Vandenplas, Dana Wallace, Susan Waserman, Arzu Yorgancioglu, Mihaela Zidarn, Torsten Zuberbier, Joao A. Fonseca, Jean Bousquet
Summary: This study analyzed data from MASK-air (R) to explore rhinitis control and treatment patterns over time. It identified 16 weekly patterns of rhinitis control and revealed common co-medication and medication change schemes in uncontrolled weeks, supporting the hypothesis that patients self-treat based on their symptoms.
Article
Medicine, Research & Experimental
Rana Charide, Lisa Stallwood, Matthew Munan, Shahab Sayfi, Lisa Hartling, Nancy J. Butcher, Martin Offringa, Sarah Elliott, Dawn P. Richards, Joseph L. Mathew, Elie A. Akl, Tamara Kredo, Lawrence Mbuagbaw, Ashley Motillal, Ami Baba, Matthew Prebeg, Jacqueline Relihan, Shannon D. Scott, Jozef Suvada, Maicon Falavigna, Miloslav Klugar, Tamara Lotfi, Adrienne Stevens, Kevin Pottie, Holger J. Schunemann
Summary: This study aims to evaluate and compare the public's understanding and preference for different presentations of COVID-19 health recommendations. The study will involve online surveys and virtual interviews. The findings will provide guidance for improving the delivery of health recommendations.
Article
Allergy
Jean Bousquet, Josep M. Anto, Bernardo Sousa-Pinto, Wienczyslawa Czarlewski, Anna Bedbrook, Tari Haahtela, Ludger Klimek, Oliver Pfaar, Piotr Kuna, Maciej Kupczyk, Frederico S. Regateiro, Boleslaw Samolinski, Arunas Valiulis, Arzu Yorgancioglu, Sylvie Arnavielhe, Xavier Basagana, Karl C. Bergmann, Sinthia Bosnic-Anticevich, Luisa Brussino, G. Walter Canonica, Victoria Cardona, Lorenzo Cecchi, Claudia Chaves-Loureiro, Elisio Costa, Alvaro A. Cruz, Bilun Gemicioglu, Wytske J. Fokkens, Juan Carlos Ivancevich, Helga Kraxner, Violeta Kvedariene, Desiree E. Larenas-Linnemann, Daniel Laune, Renaud Louis, Michael Makris, Marcus Maurer, Erik Melen, Yann Micheli, Mario Morais-Almeida, Joaquim Mullol, Marek Niedoszytko, Yoshitaka Okamoto, Nikolaos G. Papadopoulos, Vincenzo Patella, Nhan Pham-Thi, Philip W. Rouadi, Joaquin Sastre, Nicola Scichilone, Aziz Sheikh, Mikhail Sofiev, Luis Taborda-Barata, Sanna Toppila-Salmi, Ioanna Tsiligianni, Erkka Valovirta, Maria Teresa Ventura, Rafael Jose Vieira, Mihaela Zidarn, Rita Amaral, Ignacio J. Ansotegui, Annabelle Bedard, Samuel Benveniste, Michael Bewick, Carsten Bindslev-Jensen, Hubert Blain, Matteo Bonini, Rodolphe Bourret, Fulvio Braido, Pedro Carreiro-Martins, Denis Charpin, Ivan Cherrez-Ojeda, Tomas Chivato, Derek K. Chu, Cemal Cingi, Stefano Del Giacco, Frederic de Blay, Philippe Devillier, Govert De Vries, Maria Doulaptsi, Virginie Doyen, Gerard Dray, Jean-Francois Fontaine, R. Maximiliano Gomez, Jan Hagemann, Enrico Heffler, Maja Hofmann, Ewa Jassem, Marek Jutel, Thomas Keil, Vicky Kritikos, Inger Kull, Marek Kulus, Olga Lourenco, Eve Mathieu-Dupas, Enrica Menditto, Ralph Mosges, Ruth Murray, Rachel Nadif, Hugo Neffen, Stefania Nicola, Robyn O'Hehir, Heidi Olze, Yuliia Palamarchuk, Jean-Louis Pepin, Benoit Petre, Robert Picard, Constantinos Pitsios, Francesca Puggioni, Santiago Quirce, Filip Raciborski, Sietze Reitsma, Nicolas Roche, Monica Rodriguez-Gonzalez, Jan Romantowski, Ana Sa-Sousa, Faradiba S. Serpa, Marine Savoure, Mohamed H. Shamji, Milan Sova, Annette Sperl, Cristiana Stellato, Ana Todo-Bom, Peter Valentin Tomazic, Olivier Vandenplas, Michiel Van Eerd, Tuula Vasankari, Frederic Viart, Susan Waserman, Joao A. Fonseca, Torsten Zuberbier
Summary: MASK-air is a validated mHealth app that has enabled large-scale implementation studies in over 58,000 people with allergic rhinitis and/or asthma. It can address unmet patient needs in rhinitis and asthma care. MASK-air is recognized as a Good Practice by DG Sante and a candidate Good Practice by OECD.
CLINICAL AND TRANSLATIONAL ALLERGY
(2023)
Review
Pediatrics
Niveditha Devasenapathy, Alexandro Chu, Melanie Wong, Archita Srivastava, Renata Ceccacci, Clement Lin, Margaret MacDonald, Aaron Wen, Jeremy Steen, Mitchell Levine, Lonnie Pyne, Lynda Schneider, Derek K. Chu
Summary: This study systematically reviewed the risk of cancer in patients with atopic dermatitis using topical calcineurin inhibitors. The analysis of 110 studies found no significant association between the use of topical calcineurin inhibitors and cancer risk. These findings support the safe use of topical calcineurin inhibitors in the treatment of patients with atopic dermatitis.
LANCET CHILD & ADOLESCENT HEALTH
(2023)
Editorial Material
Medicine, General & Internal
Anna Whalen-Browne, Hywel C. Williams, Derek K. Chu
CANADIAN MEDICAL ASSOCIATION JOURNAL
(2023)
Review
Allergy
Manal Bel Imam, Charalampos-Vlasios Stikas, Payal Guha, Bo L. Chawes, Derek Chu, Matthew Greenhawt, Ekaterina Khaleva, Daniel Munblit, Nikita Nekliudov, Willem van de Veen, Ann-Marie M. Schoos
Summary: Background: Mixed and non-IgE-mediated food allergy can greatly impact the quality of life for patients and their families. This study aimed to assess the outcomes reported in clinical trials for these conditions, and found that the current reporting is inconsistent and lacks validation. It highlights the need for the development of core outcome measures to support effective treatments.
CLINICAL AND EXPERIMENTAL ALLERGY
(2023)
Review
Allergy
Matthew Greenhawt, Timothy E. Dribin, Elissa M. Abrams, Marcus Shaker, Derek K. Chu, David B. K. Golden, Cem Akin, Akterini Anagnostou, Faisal Almuhizi, Waleed Alqurashi, Peter Arkwright, James L. Baldwin, Aleena Banerji, Philippe Begin, Moshe Ben-Shoshan, Jonathan Bernstein, Theresa A. Bingemann, Carsten Bindslev-Jensen, Kim Blumenthal, Aideen Byrne, Julia Cahill, Scott Cameron, Dianne Campbell, Ronna Campbell, Michael Cavender, Edmond S. Chan, Sharon Chinthrajah, Pasquale Comberiati, Jacqueline J. Eastman, Anne K. Ellis, David M. Fleischer, Adam Fox, Pamela A. Frischmeyer-Guerrerio, Remi Gagnon, Lene H. Garvey, Mitchell H. Grayson, Ghislaine Annie Clarisse Isabwe, Nicholas Hartog, David Hendron, Caroline C. Horner, Johnathan O'B Hourihane, Edward Iglesia, Manstein Kan, Blanka Kaplan, Constance H. Katelaris, Harold Kim, John M. Kelso, David A. Khan, David Lang, Dennis Ledford, Michael Levin, Jay A. Lieberman, Richard Loh, Douglas P. Mack, Bruce Mazer, Ketan Mody, Gisele Mosnaim, Daniel Munblit, S. Shahzad Mustafa, Anil Nanda, Richard Nathan, John Oppenheimer, Iris M. Otani, Miguel Park, Ruby Pawankar, Kirsten P. Perrett, Jonny Peter, Elizabeth J. Phillips, Matthieu Picard, Mitchell Pitlick, Allison Ramsey, Trine Holm Rasmussen, Melinda M. Rathkopf, Hari Reddy, Kara Robertson, Pablo Rodriguez del Rio, Stephen Sample, Ajay Sheshadri, Javed Sheik, Sayantani B. Sindher, Jonathan M. Spergel, Cosby A. Stone, David Stukus, Mimi L. K. Tang, James M. Tracy, Paul J. Turner, Timothy K. Vander Leek, Dana V. Wallace, Julie Wang, Susan Wasserman, David Weldon, Anna R. Wolfson, Margitta Worm, Mona-Rita Yacoub
Summary: This guidance provides updates on immediate allergic reactions following COVID-19 vaccines, including recommendations for revaccinating individuals with first-dose allergic reactions and conducting allergy testing. The recommendations were formed by an international panel of experts and are based on recent meta-analyses and diagnostic accuracy studies.
JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY
(2023)
Article
Health Care Sciences & Services
Martin Ragusaa, Fernando Tortosaa, Gabriel Radab, Camilo Vergarab, Leslie Zaragozaa, Jenee Farrella, Marcela Torresa, Veronica Abdalaa, Ariel Izcovicha, Michelle Habya, Holger J. Schunemannc, Sebastian Garcia-Saisoa, Ludovic Reveiza
Summary: This article describes the establishment and maintenance of a living database of recommendations developed by the PAHO/WHO using the GRADE assessment system. The database provides a valuable resource for health professionals and organizations to make evidence-informed decisions. It allows searching and filtering recommendations by various criteria.
JOURNAL OF CLINICAL EPIDEMIOLOGY
(2023)
Article
Health Care Sciences & Services
Gordon Guyatt, Yunli Zhao, Martin Mayer, Matthias Briel, Reem Mustafa, Ariel Izcovich, Monica Hultcrantz, Alfonso Iorio, Ana Carolina Alba, Farid Foroutan, Xin Sun, Holger Schunemann, Hans DeBeer, Elie A. Akl, Robin Christensen, Stefan Schandelmaier
Summary: This study updates previous GRADE guidance by addressing inconsistencies and interpreting subgroup analyses through an iterative process of consultation with members of the GRADE working group.
JOURNAL OF CLINICAL EPIDEMIOLOGY
(2023)
Article
Hematology
Ignacio Neumann, Ariel Izcovich, Ricardo Aguilar, Guillermo Leon Basantes, Patricia Casais, Cecilia C. Colorio, Maria Cecilia Guillermo Esposito, Pedro P. Garcia Lazaro, Jaime Pereira, Luis A. Meillon Garcia, Suely Meireles Rezende, Juan Carlos Serrano, Mario L. Tejerina Valle, Diana Altuna, Pamela Zuniga, Felipe Vera, Lorena Karzulovic, Holger J. Schunemann
Summary: This study aims to provide evidence-based recommendations for the diagnosis and management of venous thromboembolism (VTE) in children and during pregnancy in Latin American settings. By collaborating with the American Society of Hematology (ASH) and local hematology societies, a guideline panel was formed and recommendations were adapted based on the Latin American context. This study emphasizes the importance of contextualizing guidelines in different settings to ensure feasibility and equity in healthcare.
Editorial Material
Allergy
G. Walter Canonica, Ioana Agache, Holger J. Schunemann, Nicolas Roche, David Price, Stefano del Giacco
Review
Medicine, General & Internal
Elena Kum, Matthew Patel, Nermin Diab, Mustafaa Wahab, Dena Zeraatkar, Derek K. Chu, Paul M. O'Byrne, Gordon H. Guyatt, Imran Satia
Summary: Gefapixant is a potential therapy for refractory or unexplained chronic cough. This study evaluated its efficacy and tolerability in adults with this condition. The findings suggest that Gefapixant can lead to modest improvements in cough frequency, severity, and quality of life, but it may also increase taste-related adverse events.
JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION
(2023)
Article
Pediatrics
Lisa Stallwood, Adrian Sammy, Matthew Prebeg, Jacqueline Relihan, Ami Baba, Rana Charide, Shahab Sayfi, Sarah A. Elliott, Lisa Hartling, Matthew Munan, Dawn P. Richards, Joseph L. Mathew, Tamara Kredo, Lawrence Mbuagbaw, Ashley Motilall, Shannon D. Scott, Miloslav Klugar, Tamara Lotfi, Adrienne L. Stevens, Kevin Pottie, Holger J. Schuenemann, Nancy J. Butcher, Martin Offringa, RecMap Members
Summary: To ensure informed decision making by youths regarding their health, it is important to present health recommendations in a way that is easily understandable by youths.