{"id":"https://openalex.org/W2127719902","doi":"https://doi.org/10.1136/bmj.327.7418.785","title":"Evidence for risk of bias in cluster randomised trials: review of recent trials published in three general medical journals","display_name":"Evidence for risk of bias in cluster randomised trials: review of recent trials published in three general medical journals","publication_year":2003,"publication_date":"2003-10-02","ids":{"openalex":"https://openalex.org/W2127719902","doi":"https://doi.org/10.1136/bmj.327.7418.785","mag":"2127719902","pmid":"https://pubmed.ncbi.nlm.nih.gov/14525877","pmcid":"https://www.ncbi.nlm.nih.gov/pmc/articles/214092"},"language":"en","primary_location":{"id":"doi:10.1136/bmj.327.7418.785","doi":"https://doi.org/10.1136/bmj.327.7418.785","is_oa":true,"landing_page_url":"https://doi.org/10.1136/bmj.327.7418.785","pdf_url":"https://www.bmj.com/content/bmj/327/7418/785.full.pdf","source":{"id":"https://openalex.org/S4393911389","display_name":"BMJ","issn_l":"0007-1447","issn":["0007-1447","0267-0623","1468-5833"],"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":["anvur-scientific","vabb-shw"],"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"BMJ","raw_type":"journal-article"},"volume":null,"type":"article","is_traditional":true,"indexed_in":["crossref","pubmed"],"open_access":{"is_oa":true,"oa_status":"bronze","oa_url":"https://www.bmj.com/content/bmj/327/7418/785.full.pdf","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5002356650","display_name":"Suezann Puffer","orcid":null,"observed_orcids":[]},"institutions":[{"id":"https://openalex.org/I192455969","display_name":"York University","ror":"https://ror.org/05fq50484","country_code":"CA","type":"education","lineage":["https://openalex.org/I192455969"]},{"id":"https://openalex.org/I4210112962","display_name":"York University","ror":"https://ror.org/022jz8688","country_code":"US","type":"education","lineage":["https://openalex.org/I4210112962"]},{"id":"https://openalex.org/I52099693","display_name":"University of York","ror":"https://ror.org/04m01e293","country_code":"GB","type":"education","lineage":["https://openalex.org/I52099693"]}],"countries":["CA","GB","US"],"is_corresponding":true,"raw_author_name":"Suezann Puffer","raw_affiliation_strings":["York Trials Unit, Department of Health Sciences, York University, York YO10 5DD"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"York Trials Unit, Department of Health Sciences, York University, York YO10 5DD","institution_ids":["https://openalex.org/I192455969","https://openalex.org/I4210112962","https://openalex.org/I52099693"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5100681877","display_name":"David John Torgerson","orcid":"https://orcid.org/0000-0002-1667-4275","observed_orcids":["https://orcid.org/0000-0002-1667-4275"]},"institutions":[{"id":"https://openalex.org/I192455969","display_name":"York University","ror":"https://ror.org/05fq50484","country_code":"CA","type":"education","lineage":["https://openalex.org/I192455969"]},{"id":"https://openalex.org/I4210112962","display_name":"York University","ror":"https://ror.org/022jz8688","country_code":"US","type":"education","lineage":["https://openalex.org/I4210112962"]},{"id":"https://openalex.org/I52099693","display_name":"University of York","ror":"https://ror.org/04m01e293","country_code":"GB","type":"education","lineage":["https://openalex.org/I52099693"]}],"countries":["CA","GB","US"],"is_corresponding":false,"raw_author_name":"David Torgerson","raw_affiliation_strings":["York Trials Unit, Department of Health Sciences, York University, York YO10 5DD"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"York Trials Unit, Department of Health Sciences, York University, York YO10 5DD","institution_ids":["https://openalex.org/I192455969","https://openalex.org/I4210112962","https://openalex.org/I52099693"]}]},{"author_position":"last","author":{"id":null,"display_name":"Judith Watson","orcid":null,"observed_orcids":[]},"institutions":[{"id":"https://openalex.org/I192455969","display_name":"York University","ror":"https://ror.org/05fq50484","country_code":"CA","type":"education","lineage":["https://openalex.org/I192455969"]},{"id":"https://openalex.org/I4210112962","display_name":"York University","ror":"https://ror.org/022jz8688","country_code":"US","type":"education","lineage":["https://openalex.org/I4210112962"]},{"id":"https://openalex.org/I52099693","display_name":"University of York","ror":"https://ror.org/04m01e293","country_code":"GB","type":"education","lineage":["https://openalex.org/I52099693"]}],"countries":["CA","GB","US"],"is_corresponding":false,"raw_author_name":"Judith Watson","raw_affiliation_strings":["York Trials Unit, Department of Health Sciences, York University, York YO10 5DD"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"York Trials Unit, Department of Health Sciences, York University, York YO10 5DD","institution_ids":["https://openalex.org/I192455969","https://openalex.org/I4210112962","https://openalex.org/I52099693"]}]}],"institutions":[],"countries_distinct_count":3,"institutions_distinct_count":3,"corresponding_author_ids":["https://openalex.org/A5002356650"],"corresponding_institution_ids":["https://openalex.org/I192455969","https://openalex.org/I4210112962","https://openalex.org/I52099693"],"apc_list":null,"apc_paid":null,"fwci":11.7963,"has_fulltext":true,"cited_by_count":351,"citation_normalized_percentile":{"value":0.99090121,"is_in_top_1_percent":true,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":98,"max":100},"biblio":{"volume":"327","issue":"7418","first_page":"785","last_page":"789"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11235","display_name":"Statistical Methods in Clinical Trials","score":0.5189999938011169,"subfield":{"id":"https://openalex.org/subfields/2613","display_name":"Statistics and Probability"},"field":{"id":"https://openalex.org/fields/26","display_name":"Mathematics"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T11235","display_name":"Statistical Methods in Clinical Trials","score":0.5189999938011169,"subfield":{"id":"https://openalex.org/subfields/2613","display_name":"Statistics and Probability"},"field":{"id":"https://openalex.org/fields/26","display_name":"Mathematics"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10206","display_name":"Meta-analysis and systematic reviews","score":0.4293999969959259,"subfield":{"id":"https://openalex.org/subfields/1804","display_name":"Statistics, Probability and Uncertainty"},"field":{"id":"https://openalex.org/fields/18","display_name":"Decision Sciences"},"domain":{"id":"https://openalex.org/domains/2","display_name":"Social Sciences"}},{"id":"https://openalex.org/T10629","display_name":"Health Policy Implementation Science","score":0.011800000444054604,"subfield":{"id":"https://openalex.org/subfields/3600","display_name":"General Health Professions"},"field":{"id":"https://openalex.org/fields/36","display_name":"Health Professions"},"domain":{"id":"https://openalex.org/domains/4","display_name":"Health Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/risk-of-bias","display_name":"risk of bias","score":0.9309999942779541},{"id":"https://openalex.org/keywords/allocation-concealment","display_name":"allocation concealment","score":0.7889999747276306},{"id":"https://openalex.org/keywords/differential-attrition","display_name":"differential attrition","score":0.8199999928474426},{"id":"https://openalex.org/keywords/internal-validity","display_name":"internal validity","score":0.5519999861717224},{"id":"https://openalex.org/keywords/general-medical-journals","display_name":"general medical journals","score":0.5109999775886536}],"concepts":[{"id":"https://openalex.org/C71924100","wikidata":"https://www.wikidata.org/wiki/Q11190","display_name":"Medicine","level":0,"score":0.6670979261398315},{"id":"https://openalex.org/C164866538","wikidata":"https://www.wikidata.org/wiki/Q367351","display_name":"Cluster (spacecraft)","level":2,"score":0.6098355054855347},{"id":"https://openalex.org/C535046627","wikidata":"https://www.wikidata.org/wiki/Q30612","display_name":"Clinical trial","level":2,"score":0.5141646862030029},{"id":"https://openalex.org/C129848803","wikidata":"https://www.wikidata.org/wiki/Q2564360","display_name":"Sample size determination","level":2,"score":0.46765345335006714},{"id":"https://openalex.org/C168563851","wikidata":"https://www.wikidata.org/wiki/Q1436668","display_name":"Randomized controlled trial","level":2,"score":0.4614827036857605},{"id":"https://openalex.org/C176400912","wikidata":"https://www.wikidata.org/wiki/Q3058662","display_name":"Cluster randomised controlled trial","level":3,"score":0.4611433148384094},{"id":"https://openalex.org/C2777098013","wikidata":"https://www.wikidata.org/wiki/Q5468626","display_name":"Foreknowledge","level":2,"score":0.43643227219581604},{"id":"https://openalex.org/C2780553607","wikidata":"https://www.wikidata.org/wiki/Q684868","display_name":"Attrition","level":2,"score":0.41864073276519775},{"id":"https://openalex.org/C512399662","wikidata":"https://www.wikidata.org/wiki/Q3505712","display_name":"Family medicine","level":1,"score":0.41158217191696167},{"id":"https://openalex.org/C126322002","wikidata":"https://www.wikidata.org/wiki/Q11180","display_name":"Internal medicine","level":1,"score":0.11963307857513428},{"id":"https://openalex.org/C105795698","wikidata":"https://www.wikidata.org/wiki/Q12483","display_name":"Statistics","level":1,"score":0.11316603422164917},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.0},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.0},{"id":"https://openalex.org/C199360897","wikidata":"https://www.wikidata.org/wiki/Q9143","display_name":"Programming language","level":1,"score":0.0},{"id":"https://openalex.org/C138885662","wikidata":"https://www.wikidata.org/wiki/Q5891","display_name":"Philosophy","level":0,"score":0.0},{"id":"https://openalex.org/C199343813","wikidata":"https://www.wikidata.org/wiki/Q12128","display_name":"Dentistry","level":1,"score":0.0},{"id":"https://openalex.org/C111472728","wikidata":"https://www.wikidata.org/wiki/Q9471","display_name":"Epistemology","level":1,"score":0.0}],"mesh":[{"descriptor_ui":"D006801","descriptor_name":"Humans","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D007258","descriptor_name":"Informed Consent","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D010506","descriptor_name":"Periodicals as Topic","qualifier_ui":"Q000592","qualifier_name":"standards","is_major_topic":false},{"descriptor_ui":"D010506","descriptor_name":"Periodicals as Topic","qualifier_ui":"Q000706","qualifier_name":"statistics & numerical data","is_major_topic":false},{"descriptor_ui":"D012189","descriptor_name":"Retrospective Studies","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D015982","descriptor_name":"Bias","qualifier_ui":null,"qualifier_name":null,"is_major_topic":true},{"descriptor_ui":"D016000","descriptor_name":"Cluster Analysis","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false},{"descriptor_ui":"D016032","descriptor_name":"Randomized Controlled Trials as Topic","qualifier_ui":"Q000379","qualifier_name":"methods","is_major_topic":false},{"descriptor_ui":"D016032","descriptor_name":"Randomized Controlled Trials as Topic","qualifier_ui":"Q000592","qualifier_name":"standards","is_major_topic":false},{"descriptor_ui":"D016032","descriptor_name":"Randomized Controlled Trials as Topic","qualifier_ui":"Q000706","qualifier_name":"statistics & numerical data","is_major_topic":true},{"descriptor_ui":"D018579","descriptor_name":"Patient Selection","qualifier_ui":null,"qualifier_name":null,"is_major_topic":false}],"locations_count":6,"locations":[{"id":"doi:10.1136/bmj.327.7418.785","doi":"https://doi.org/10.1136/bmj.327.7418.785","is_oa":true,"landing_page_url":"https://doi.org/10.1136/bmj.327.7418.785","pdf_url":"https://www.bmj.com/content/bmj/327/7418/785.full.pdf","source":{"id":"https://openalex.org/S4393911389","display_name":"BMJ","issn_l":"0007-1447","issn":["0007-1447","0267-0623","1468-5833"],"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":["anvur-scientific","vabb-shw"],"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"BMJ","raw_type":"journal-article"},{"id":"pmh:oai:europepmc.org:440787","doi":null,"is_oa":true,"landing_page_url":"http://europepmc.org/pmc/articles/PMC214092","pdf_url":null,"source":{"id":"https://openalex.org/S4306400806","display_name":"Europe PMC (PubMed Central)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I1303153112","host_organization_name":"European Bioinformatics Institute","host_organization_lineage":["https://openalex.org/I1303153112"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"","raw_type":"Text"},{"id":"pmh:oai:pubmedcentral.nih.gov:214092","doi":null,"is_oa":true,"landing_page_url":"https://www.ncbi.nlm.nih.gov/pmc/articles/214092","pdf_url":null,"source":{"id":"https://openalex.org/S2764455111","display_name":"PubMed Central","issn_l":null,"issn":null,"is_oa":true,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I1299303238","host_organization_name":"National Institutes of Health","host_organization_lineage":["https://openalex.org/I1299303238"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"BMJ","raw_type":"Text"},{"id":"pmid:14525877","doi":null,"is_oa":false,"landing_page_url":"https://pubmed.ncbi.nlm.nih.gov/14525877","pdf_url":null,"source":{"id":"https://openalex.org/S4306525036","display_name":"PubMed","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I1299303238","host_organization_name":"National Institutes of Health","host_organization_lineage":["https://openalex.org/I1299303238"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"BMJ (Clinical research ed.)","raw_type":"Journal Article"},{"id":"pmh:oai:eprints.whiterose.ac.uk:41","doi":null,"is_oa":true,"landing_page_url":"https://orcid.org/0000-0002-1667-4275>","pdf_url":"https://eprints.whiterose.ac.uk/id/eprint/41/1/785.pdf","source":{"id":"https://openalex.org/S4306400854","display_name":"White Rose Research Online (University of Leeds, The University of Sheffield, University of York)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":[],"host_organization":"https://openalex.org/I2800616092","host_organization_name":"White Rose University Consortium","host_organization_lineage":["https://openalex.org/I2800616092"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"acceptedVersion","is_accepted":true,"is_published":false,"raw_source_name":null,"raw_type":"Article"},{"id":"pmh:oai:CiteSeerX.psu:10.1.1.872.7837","doi":null,"is_oa":false,"landing_page_url":"http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.872.7837","pdf_url":null,"source":null,"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":"https://www.researchgate.net/profile/Judith_Watson/publication/9066006_Evidence_for_risk_of_bias_in_cluster_randomised_trials_review_of_recent_trials_published_in_three_general_medical_journals/links/09e41513077dc0bc68000000.pdf","raw_type":"text"}],"best_oa_location":{"id":"doi:10.1136/bmj.327.7418.785","doi":"https://doi.org/10.1136/bmj.327.7418.785","is_oa":true,"landing_page_url":"https://doi.org/10.1136/bmj.327.7418.785","pdf_url":"https://www.bmj.com/content/bmj/327/7418/785.full.pdf","source":{"id":"https://openalex.org/S4393911389","display_name":"BMJ","issn_l":"0007-1447","issn":["0007-1447","0267-0623","1468-5833"],"is_oa":false,"is_in_doaj":false,"is_core":false,"listed_in":["anvur-scientific","vabb-shw"],"host_organization":null,"host_organization_name":null,"host_organization_lineage":[],"host_organization_lineage_names":[],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"BMJ","raw_type":"journal-article"},"sustainable_development_goals":[{"display_name":"Good health and well-being","score":0.5683000087738037,"id":"https://metadata.un.org/sdg/3"}],"study_designs":[],"awards":[],"funders":[{"id":"https://openalex.org/F4320334626","display_name":"Medical Research Council","ror":"https://ror.org/03x94j517"}],"has_content":{"pdf":true,"grobid_xml":true},"content_urls":{"pdf":"https://content.openalex.org/works/W2127719902.pdf","grobid_xml":"https://content.openalex.org/works/W2127719902.grobid-xml"},"referenced_works_count":16,"referenced_works":["https://openalex.org/W1579695515","https://openalex.org/W1603654133","https://openalex.org/W1882720819","https://openalex.org/W1971785694","https://openalex.org/W1984052453","https://openalex.org/W1987428178","https://openalex.org/W1998284307","https://openalex.org/W2012958050","https://openalex.org/W2051683917","https://openalex.org/W2064193170","https://openalex.org/W2072070392","https://openalex.org/W2083472170","https://openalex.org/W2117294447","https://openalex.org/W2120519513","https://openalex.org/W2123697166","https://openalex.org/W2410120904"],"related_works":["https://openalex.org/W3173469077","https://openalex.org/W170632508","https://openalex.org/W1958931973","https://openalex.org/W2792037397","https://openalex.org/W2901973827","https://openalex.org/W2417422374","https://openalex.org/W4238765913","https://openalex.org/W4290974967","https://openalex.org/W2147119554","https://openalex.org/W2047660576"],"abstract_inverted_index":{"OBJECTIVE:":[0],"To":[1],"examine":[2],"the":[3,12,37,88,96,99,106,113,137,150,176],"prevalence":[4],"of":[5,8,16,24,31,44,56,59,62,69,78,110,134,143,147,179],"a":[6,22,102],"risk":[7,146],"bias":[9,148],"associated":[10],"with":[11],"design":[13],"and":[14,40,80,83,101,124],"conduct":[15],"cluster":[17,32,114,138,162],"randomised":[18,33,163],"controlled":[19],"trials":[20,34,90,118,131,164],"among":[21],"sample":[23],"recently":[25,160],"published":[26,35,94,161],"studies.":[27,157],"DESIGN:":[28],"Retrospective":[29],"review":[30],"in":[36,95,98,105,154],"BMJ,":[38],"Lancet,":[39,100],"New":[41,107],"England":[42,108],"Journal":[43,109],"Medicine":[45],"from":[46],"January":[47],"1997":[48],"to":[49,145,171,175],"October":[50],"2002.":[51],"MAIN":[52],"OUTCOME":[53],"MEASURES:":[54],"Prevalence":[55],"secure":[57,122],"randomisation":[58,65],"clusters,":[60],"identification":[61],"participants":[63],"before":[64],"(to":[66],"avoid":[67],"foreknowledge":[68],"allocation),":[70],"differential":[71,76,84],"recruitment":[72],"between":[73],"treatment":[74],"arms,":[75],"application":[77],"inclusion":[79],"exclusion":[81],"criteria,":[82],"attrition.":[85],"RESULTS:":[86],"Of":[87],"36":[89],"identified,":[91],"24":[92],"were":[93],"BMJ,11":[97],"single":[103],"trial":[104],"Medicine.":[111],"At":[112],"level,":[115],"15":[116],"(42%)":[117],"provided":[119],"evidence":[120,133,142],"for":[121],"allocation":[123],"25":[125],"(69%)":[126],"used":[127],"stratified":[128],"allocation.":[129],"Few":[130],"showed":[132],"imbalance":[135],"at":[136,149],"level.":[139],"However,":[140],"some":[141],"susceptibility":[144],"individual":[151],"level":[152],"existed":[153],"14":[155],"(39%)":[156],"CONCLUSIONS:":[158],"Some":[159],"may":[165],"not":[166],"have":[167],"taken":[168],"adequate":[169],"precautions":[170],"guard":[172],"against":[173],"threats":[174],"internal":[177],"validity":[178],"their":[180],"design.":[181]},"counts_by_year":[{"year":2026,"cited_by_count":5},{"year":2025,"cited_by_count":8},{"year":2024,"cited_by_count":9},{"year":2023,"cited_by_count":13},{"year":2022,"cited_by_count":10},{"year":2021,"cited_by_count":11},{"year":2020,"cited_by_count":13},{"year":2019,"cited_by_count":22},{"year":2018,"cited_by_count":13},{"year":2017,"cited_by_count":8},{"year":2016,"cited_by_count":19},{"year":2015,"cited_by_count":24},{"year":2014,"cited_by_count":15},{"year":2013,"cited_by_count":25},{"year":2012,"cited_by_count":23}],"updated_date":"2026-11-07T11:25:07.637180","created_date":"2016-06-24T00:00:00"}