Evidence table for systematic reviews

Evidence table for systematic reviews Topic: CB use and dependence Reviewer: CMF Abbreviations: y- years Reference Research Parameters Population Outcomes Funding Additional comments Bibliographic reference Research question Theoretical approach Data Study type and quality Population and sample Gender Age Key themes Source of funding Limitations Evidence gap OCEBM level of evidence [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] Degenhardt et al. MA Not reported Not Not 2013 (PLOS) reported reported Contribution of CBuse and dependence to Global Burden of Disease Medline, EMBASE, PsycInfo, handsearched, expert consultation 01/1990 01/2008 Total number of yielded papers not reported 13 epidemiological studies on prevalence of CB dependence, 7 on prevalence of weekly CB use, 80 on prevalence of past year CB use, 3 general population cohort studies on incidence of CBuse and dependence Study quality assessed and reported (in cited earlier publications of this group) > no epidemiological evidence for increased mortality due to CB dependence > global prevalence estimate of CB dependence 0.19% (2010) and 0.2% (1999), corresponds to 13 (2010) and 11 (1999) million cases worldwide > prevalence higher in males (0.23%) than females (0.14%), higher in high-income (Australasia, North America, Western Europe) 0.26-0.68% than in low and middle income regions 0.08-0.23%, peaking in 20-24y age-group (max. 0.38% in males, 0.22 in females) and steady decrease thereafter > Western Europe prevalence: total: 0.34%, females: 0.26%, males: 0.46% > CB dependence accounted for 0.08% of global disability-adjusted life years (DALY) in 2010 (0.07% in 1999) corresponding to 2 million DALYs > accounting for 12.5% of years of life lived with disability (YLD) attributed to illicit drug use and 0.27% of global all-cause YLD; globally more DALYs than attributed to cocaine or amphetamine (just in high income regions with available data) > majority of YLD due to CB dependence occurred in 20-24y age range (33.5%, in males 64.3%) > regular CBuse as risk factor for schizophrenia accounted for 7000 DALYs or 0.04% of schizophrenia DALYs globally; more pronounced Australian National Health and Medical Research Council, Australian Government, Queensland Department of Health, Bill and Melinda Gates Foundation > few or missing epidemiological data (maily low income regions) account for considerable uncertainty around estimated rates Gap in existing epidemiological data on CB depedence Methodological rating SIGN 2 High quality ++ 1

Reference Research Parameters Population Outcomes Funding Additional comments Bibliographic reference Research question Theoretical approach Data Study type and quality Population and sample Gender Age Key themes Source of funding Limitations Evidence gap OCEBM level of evidence [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] in males than females (5000 vs. 2000 DALYs) and peaking DALYs between 25-30y of age with subsequent steady decrease Degenhardt et al. 2011 Degenhardt & Hall 2012 Global coverage of illicit drug use and dependence estimates Summary of prevalence, correlates and probable adverse health effects of problem use of amphetamines, CB, cocaine and opiods MA MA Medline, EMBASE, PsycInfo, LILACS, grey literature 1990-2008 Yielded 1857 papers for CB Medline, EMBASE, PsycInfo, handsearched, expert consultation 01/1990 01/2008 Total number of yielded papers not reported 191 data sources (cohort studies, general population epidemiological studies, national estimates of prevalence (183) and incidence (8) Study quality assessed and reported Number of included studies not reported Epidemiological data of cohort studies and representative household surveys Study quality assessed but not reported Representative global population from 201 countries/ territories (>99% of population aged 15-64y) Representative global population (aged 15-64y) Not reported Not reported 15-64y > CBuse or dependence is reported in 201 (from 229) territories/countries representing >99% of global population aged 15-64y > estimates of CBuse from 95 countries, of CB dependence from 7 countries data from Germany (2006) > CBuse prevalence last year 4.7%, lifetime 23% > CB dependence last year prevalence 0.4% (18-64y), lifetime 3.1% (24-34y) 15-64y CBuse > estimate of CBuse: 2.8 4.5% (2009, global population 15-64y) corresponding to 125-203 Mio people; highest rates in North America, Western Europe and Oceania > common temporal order of drug initiation in high-income countries: alcohol/tobacco CB other illicit drugs; not consistently evident in all countries > more common in males than females > peaking in young adulthood with subsequent decrease > health-related harm of CB differs qualitatively from other illicit drugs; contributes more to morbidity than mortality; major adverse effect is CB dependence > risk factors for regular CBuse: social contextual factors (drug availability, alcohol/ tobacco use at early age, drug-tolerant social norms, socioeconomic status, poverty, social and cultural factors), family factors (poor quality of parent-child relationship, parental conflict, parental/ sibling drug use), individual risk factors (male, strong novelty/ sensation seeking, oppositional behaviour/ conduct disorder during childhood, poor Australian National Drug and Research Centre (NDARC), Australian National Health and Medical Research Council Not mentioned > regional comparisons of prevalence rates restricted by inconsistent, incomplete, outdated and unclear /reporting > prevalence of CB dependence rarely studied > inconsistent types of measurement between studies (direct vs. indirect estimates> reporting bias) > accuracy of estimated exact magnitude of health, social and financial burden limited due to lacking data > burden of illicit drugs underestimated as not all adverse outcomes included > need for more prospective, quantitative, longitudinal studies of specific patterns of drug use and their specific outcomes > adverse effects of polydrug use (instead of single drug) not clear Methodological rating SIGN 2 High quality ++ 2 High quality ++ 2

Reference Research Parameters Population Outcomes Funding Additional comments Bibliographic reference Research question Theoretical approach Data Study type and quality Population and sample Gender Age Key themes Source of funding Limitations Evidence gap OCEBM level of evidence [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] school performance, low educational commitment, early school leaving), affiliation with peers (antisocial, drug-using) is one of the strongest predictors of adolescent alcohol and further drug use > risk factors co-occur often CB dependence > according to ICD-10/ DSM IV criteria past year prevalence estimate in adults is 0.1 1.5% (7 countries from North America, Western Europe, Australia, Southeast Asia) > risk factors of illicit drug dependence: earlier age of drug onset, polysubstance use, development of externalizing and internalizing disorders < 15y of age > dependence lifetime risk: 9% for CB (vs. 23% for heroin) Adverse health effects of CB use: > cognitive and behavioral impairments (especially sustained attention) > increased risk of traffic accidents > consistent association of early CBuse onset, regular CBuse and later diagnosis of schizophrenia; CBuse plausible contributory cause of schizophrenia in vulnerable individuals > less consistent association for CBuse and depression > insufficient available evidence for CBuse and suicide > no evidence for CBuse and increased mortality > Degenhardt et al. 2013 (Lancet) Summary of prevalence and disease burden of illicit drug use from Global Burden of Disease Study 2010 and Comparative Risk Assessment 2002 MA Medline, EMBASE, PsycInfo, handsearched, expert consultation 01/1990 12/2008 Total number of Number of included studies not reported Epidemiological data of cohort studies and representative household surveys Study quality assessed but not reported Representative global population (aged 15-64y) Not reported 15-64y > opioid and amphetamine dependence most common although CB most frequently consumed illicit drug > estimated prevalence of CB dependence: overall 0.19% (13.1 Mio), Australasia/ Northern America/ Western Europe 0.34-0.68% > CB dependence is estimated to account for overall 2.057.000 disability adjusted life-years (DALYs) which all represent years Australian National Health and Medical Research Council, Australian Government Department of Health and Ageing, Bill and Melinda Gates > burden of illicit drugs underestimated as not all adverse outcomes included > evidence of causal link of CBuse and suicide, cancer and accidental injuries to weak to be included > disability measure limited to health outcomes (not social or economic consequences) Methodological rating SIGN 2 High quality ++ 3

Reference Research Parameters Population Outcomes Funding Additional comments Bibliographic reference Research question Theoretical approach Data Study type and quality Population and sample Gender Age Key themes Source of funding Limitations Evidence gap OCEBM level of evidence [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] yielded papers not reported of life lived with disability (YLD), no years of life lost (YLL) due to no signs of increased mortality > mainly attributable to men 64% (1.323.000, women 734.000) consistent in all age groups > represents 10.3% of illicit drug dependence burden > fairly consistent age pattern in all illicit drug dependences: sharp increase in DALYs between 15-24y, peak between 20-30y, steady decline thereafter; steepest decline for CB > higher proportion of burden in high-income regions Foundation Calabria et al. 2010 Remission from dependence upon amphetamines, CB, cocaine and opioids SR Medline, EMBASE, PsycInfo, handsearched, expert consultation 01/1990 03/2009 Yielded 389 papers for CB 3 prospective population based studies included Study quality assessed and reported General population of Australia (138), USA (33) and Germany (37) 26.8% male or not reported Age range: 14-32y > remission rates within single studies: Australia 53% (4y followup), USA 36% (4y follow-up), Germany 82% (10y follow-up) > conservative, pooled estimate for remission of CBdependence: 0.173 > highest remission rate for CBdependence, followed by amphetamine, opiod and cocaine dependence Australian National Drug and Research Centre (NDARC), Australian National Health and Medical Research Council > limited evidence > definition of remission varies between studies or is not clearly described > great need for more studies in more settings across more countries > impact of polydrug use on remission Methodological rating SIGN 3 High quality ++ Peters et al. 2012 Clinical diagnoses, psychosocial problems and outcomes associated with co-occurring CB and tobacco use SR Medline, PsycInfo, Pubmed, handsearched Yielded 3029 papers 28 included studies (treatment studies, cross-sectional epidemiological surveys and cohort studies) Study quality not assessed and reported Total N: 192.946 samples mainly from North America, and Australia,2 from Western Europe Not reported Not reported, adolescent and adult samples > comparison of CB+tobacco (CT) users with only CB (C) or tobacco (T) users: CB use disorder > 11 studies; current and lifetime CBuse in CT (compared to C) associated with increased rates or severity of CB abuse or dependence, more symptoms of CBdependence and withdrawl and increased likelihood of withdrawl symptoms > less reliable data on higher prevalence of CB use disorder or dependence in CT users Tobacco use disorder > inconsistent findings in 5 studies; higher CBuse in CT associated to higher nicotine dependence rates (compared to T) Psychosocial problems National Institute on Drug Abuse (NIDA) > small number of studies > not all studies adjusted for potential confounders (methodological weakness) > variable assessment of CT use and clinical outcomes 2 Acceptable quality + 4

S I G N Methodology Checklist 1: Systematic Reviews and Metaanalyses SIGN gratefully acknowledges the permission received from the authors of the AMSTAR tool to base this checklist on their work: Shea BJ, Grimshaw JM, Wells GA, Boers M, Andersson N, Hamel C,. et al. Development of AMSTAR: a measurement tool to assess the methodological quality of systematic reviews. BMC Medical Research Methodology 2007, 7:10 doi:10.1186/1471-2288-7-10. Available from http://www.biomedcentral.com/1471-2288/7/10 [cited 10 Sep 2012] Study identification (Include author, title, year of publication, journal title, pages) Calabria et al. 2010 Systematic review of prospective studies investigating remission from amphetamine, cannabis, cocaine or opioid dependence. Addict Behav Guideline topic: CB use and dependence Key Question No: Before completing this checklist, consider: Is the paper relevant to key question? Analyse using PICO (Patient or Population Intervention Comparison Outcome). IF NO reject. IF YES complete the checklist. Checklist completed by: CMF Section 1: Internal validity In a well conducted systematic review: 1.1 The research question is clearly defined and the inclusion/ exclusion criteria must be listed in the paper. Does this study do it? No 1.2 A comprehensive literature search is carried out. 1.3 At least two people should have selected studies. 1.4 At least two people should have extracted data. 1.5 The status of publication was not used as an inclusion criterion. No No Can t say No Can t say No 1.6 The excluded studies are listed. Yes No x 1.7 The relevant characteristics of the included studies are provided. No

1.8 The scientific quality of the included studies was assessed and reported. 1.9 Was the scientific quality of the included studies used appropriately? 1.10 Appropriate methods are used to combine the individual study findings. 1.11 The likelihood of publication bias was assessed appropriately. Can t say No No No No 1.12 Conflicts of interest are declared. No SECTION 2: OVERALL ASSESSMENT OF THE STUDY 2.1 What is your overall assessment of the methodological quality of this review? 2.2 Are the results of this study directly applicable to the patient group targeted by this guideline? 2.3 Notes: High quality (++) x Acceptable (+) Low quality (-) Unacceptable reject 0 Yes No

S I G N Methodology Checklist 1: Systematic Reviews and Metaanalyses SIGN gratefully acknowledges the permission received from the authors of the AMSTAR tool to base this checklist on their work: Shea BJ, Grimshaw JM, Wells GA, Boers M, Andersson N, Hamel C,. et al. Development of AMSTAR: a measurement tool to assess the methodological quality of systematic reviews. BMC Medical Research Methodology 2007, 7:10 doi:10.1186/1471-2288-7-10. Available from http://www.biomedcentral.com/1471-2288/7/10 [cited 10 Sep 2012] Study identification (Include author, title, year of publication, journal title, pages) Degenhardt & Hall 2012 Extent of illicit drug use and dependence, and their contribution to the global burden of disease. Lancet Guideline topic: CB use and dependence Key Question No: Before completing this checklist, consider: Is the paper relevant to key question? Analyse using PICO (Patient or Population Intervention Comparison Outcome). IF NO reject. IF YES complete the checklist. Checklist completed by: CMF Section 1: Internal validity In a well conducted systematic review: 1.1 The research question is clearly defined and the inclusion/ exclusion criteria must be listed in the paper. Does this study do it? No 1.2 A comprehensive literature search is carried out. 1.3 At least two people should have selected studies. 1.4 At least two people should have extracted data. 1.5 The status of publication was not used as an inclusion criterion. No No Can t say No Can t say No 1.6 The excluded studies are listed. Yes No x 1.7 The relevant characteristics of the included studies are provided. Yes No x

S I G N Methodology Checklist 1: Systematic Reviews and Metaanalyses SIGN gratefully acknowledges the permission received from the authors of the AMSTAR tool to base this checklist on their work: Shea BJ, Grimshaw JM, Wells GA, Boers M, Andersson N, Hamel C,. et al. Development of AMSTAR: a measurement tool to assess the methodological quality of systematic reviews. BMC Medical Research Methodology 2007, 7:10 doi:10.1186/1471-2288-7-10. Available from http://www.biomedcentral.com/1471-2288/7/10 [cited 10 Sep 2012] Study identification (Include author, title, year of publication, journal title, pages) Degenhardt et al. 2011 What data are available on the extent of illicit drug use and dependence globally? Results from four systematic reviews. Drug Alc Dep Guideline topic: CB use and dependence Key Question No: Before completing this checklist, consider: Is the paper relevant to key question? Analyse using PICO (Patient or Population Intervention Comparison Outcome). IF NO reject. IF YES complete the checklist. Checklist completed by: CMF Section 1: Internal validity In a well conducted systematic review: 1.1 The research question is clearly defined and the inclusion/ exclusion criteria must be listed in the paper. Does this study do it? No 1.2 A comprehensive literature search is carried out. 1.3 At least two people should have selected studies. 1.4 At least two people should have extracted data. 1.5 The status of publication was not used as an inclusion criterion. No No Can t say No Can t say No 1.6 The excluded studies are listed. Yes No x 1.7 The relevant characteristics of the included studies are provided. Yes No x

S I G N Methodology Checklist 1: Systematic Reviews and Metaanalyses SIGN gratefully acknowledges the permission received from the authors of the AMSTAR tool to base this checklist on their work: Shea BJ, Grimshaw JM, Wells GA, Boers M, Andersson N, Hamel C,. et al. Development of AMSTAR: a measurement tool to assess the methodological quality of systematic reviews. BMC Medical Research Methodology 2007, 7:10 doi:10.1186/1471-2288-7-10. Available from http://www.biomedcentral.com/1471-2288/7/10 [cited 10 Sep 2012] Study identification (Include author, title, year of publication, journal title, pages) Degenhardt et al. 2013 The Global Epidemiology and Contribution of Cannabis Use and Dependence to the Global Burden of Disease: Results from GBD 2010 Study. Plos Guideline topic: CB use and dependence Key Question No: Before completing this checklist, consider: Is the paper relevant to key question? Analyse using PICO (Patient or Population Intervention Comparison Outcome). IF NO reject. IF YES complete the checklist. Checklist completed by: CMF Section 1: Internal validity In a well conducted systematic review: 1.1 The research question is clearly defined and the inclusion/ exclusion criteria must be listed in the paper. Does this study do it? No 1.2 A comprehensive literature search is carried out. 1.3 At least two people should have selected studies. 1.4 At least two people should have extracted data. 1.5 The status of publication was not used as an inclusion criterion. No No Can t say x No Can t say No 1.6 The excluded studies are listed. Yes No x 1.7 The relevant characteristics of the included studies are provided. Yes No x

S I G N Methodology Checklist 1: Systematic Reviews and Metaanalyses SIGN gratefully acknowledges the permission received from the authors of the AMSTAR tool to base this checklist on their work: Shea BJ, Grimshaw JM, Wells GA, Boers M, Andersson N, Hamel C,. et al. Development of AMSTAR: a measurement tool to assess the methodological quality of systematic reviews. BMC Medical Research Methodology 2007, 7:10 doi:10.1186/1471-2288-7-10. Available from http://www.biomedcentral.com/1471-2288/7/10 [cited 10 Sep 2012] Study identification (Include author, title, year of publication, journal title, pages) Degenhardt et al. 2013 Global burden of disease attributable to illicit drug use and dependence: findings from the Global Burden of Disease Study 2010. Lancet Guideline topic: CB use and dependence Key Question No: Before completing this checklist, consider: Is the paper relevant to key question? Analyse using PICO (Patient or Population Intervention Comparison Outcome). IF NO reject. IF YES complete the checklist. Checklist completed by: CMF Section 1: Internal validity In a well conducted systematic review: 1.1 The research question is clearly defined and the inclusion/ exclusion criteria must be listed in the paper. Does this study do it? No 1.2 A comprehensive literature search is carried out. 1.3 At least two people should have selected studies. 1.4 At least two people should have extracted data. 1.5 The status of publication was not used as an inclusion criterion. No No Can t say No Can t say No 1.6 The excluded studies are listed. Yes No x 1.7 The relevant characteristics of the included studies are provided. Yes No x

S I G N Methodology Checklist 1: Systematic Reviews and Metaanalyses SIGN gratefully acknowledges the permission received from the authors of the AMSTAR tool to base this checklist on their work: Shea BJ, Grimshaw JM, Wells GA, Boers M, Andersson N, Hamel C,. et al. Development of AMSTAR: a measurement tool to assess the methodological quality of systematic reviews. BMC Medical Research Methodology 2007, 7:10 doi:10.1186/1471-2288-7-10. Available from http://www.biomedcentral.com/1471-2288/7/10 [cited 10 Sep 2012] Study identification (Include author, title, year of publication, journal title, pages) National Academies of Sciences, Engineering, and Medicine. 2017. The health effects of cannabis and cannabinoids: The current state of evidence and recommendations for research. Washington, DC: The National Academies Press Guideline topic: CB dependence Key Question No: Before completing this checklist, consider: Is the paper relevant to key question? Analyse using PICO (Patient or Population Intervention Comparison Outcome). IF NO reject. IF YES complete the checklist. Checklist completed by: CMF Section 1: Internal validity In a well conducted systematic review: 1.1 The research question is clearly defined and the inclusion/ exclusion criteria must be listed in the paper. Does this study do it? Yes x No 1.2 A comprehensive literature search is carried out. 1.3 At least two people should have selected studies. 1.4 At least two people should have extracted data. 1.5 The status of publication was not used as an inclusion criterion. Yes x Yes Yes Yes No No Can t say x No Can t say x No x 1.6 The excluded studies are listed. Yes No x 1.7 The relevant characteristics of the included studies are provided. Yes x No

1.8 The scientific quality of the included studies was assessed and reported. 1.9 Was the scientific quality of the included studies used appropriately? 1.10 Appropriate methods are used to combine the individual study findings. 1.11 The likelihood of publication bias was assessed appropriately. Yes x Yes x Yes Can t say Yes x No No No x No 1.12 Conflicts of interest are declared. Yes x No SECTION 2: OVERALL ASSESSMENT OF THE STUDY 2.1 What is your overall assessment of the methodological quality of this review? 2.2 Are the results of this study directly applicable to the patient group targeted by this guideline? 2.3 Notes: High quality (++) Acceptable (+)X Low quality (-) Unacceptable reject 0 Yes No

S I G N Methodology Checklist 1: Systematic Reviews and Metaanalyses SIGN gratefully acknowledges the permission received from the authors of the AMSTAR tool to base this checklist on their work: Shea BJ, Grimshaw JM, Wells GA, Boers M, Andersson N, Hamel C,. et al. Development of AMSTAR: a measurement tool to assess the methodological quality of systematic reviews. BMC Medical Research Methodology 2007, 7:10 doi:10.1186/1471-2288-7-10. Available from http://www.biomedcentral.com/1471-2288/7/10 [cited 10 Sep 2012] Study identification (Include author, title, year of publication, journal title, pages) Peters, Budney & Carroll 2012 Clinical correlates of co-occurring cannabis and tobacco use: a systematic review. Addict Rev Guideline topic: CB use and dependence Key Question No: Before completing this checklist, consider: Is the paper relevant to key question? Analyse using PICO (Patient or Population Intervention Comparison Outcome). IF NO reject. IF YES complete the checklist. Checklist completed by: CMF Section 1: Internal validity In a well conducted systematic review: 1.1 The research question is clearly defined and the inclusion/ exclusion criteria must be listed in the paper. Does this study do it? No 1.2 A comprehensive literature search is carried out. 1.3 At least two people should have selected studies. 1.4 At least two people should have extracted data. 1.5 The status of publication was not used as an inclusion criterion. Yes Yes Yes No No Can t say x No Can t say x No x 1.6 The excluded studies are listed. Yes No x 1.7 The relevant characteristics of the included studies are provided. No

1.8 The scientific quality of the included studies was assessed and reported. 1.9 Was the scientific quality of the included studies used appropriately? 1.10 Appropriate methods are used to combine the individual study findings. 1.11 The likelihood of publication bias was assessed appropriately. Yes Yes Can t say Yes x No x No No x No 1.12 Conflicts of interest are declared. No SECTION 2: OVERALL ASSESSMENT OF THE STUDY 2.1 What is your overall assessment of the methodological quality of this review? 2.2 Are the results of this study directly applicable to the patient group targeted by this guideline? 2.3 Notes: High quality (++) x Acceptable (+) Low quality (-) Unacceptable reject 0 Yes No