{"id":"https://openalex.org/W223998923","doi":null,"title":"Epidemiology in practice: randomised controlled trials.","display_name":"Epidemiology in practice: randomised controlled trials.","publication_year":1998,"publication_date":"1998-01-01","ids":{"openalex":"https://openalex.org/W223998923","mag":"223998923","pmid":"https://pubmed.ncbi.nlm.nih.gov/17492029","pmcid":"https://www.ncbi.nlm.nih.gov/pmc/articles/1706053"},"language":"en","primary_location":{"id":"pmid:17492029","doi":null,"is_oa":false,"landing_page_url":"https://pubmed.ncbi.nlm.nih.gov/17492029","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":"Community eye health","raw_type":"Journal Article"},"volume":null,"type":"article","is_traditional":true,"indexed_in":["pubmed"],"open_access":{"is_oa":true,"oa_status":"green","oa_url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1706053/","any_repository_has_fulltext":true},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5091162454","display_name":"Jennifer R Evans","orcid":"https://orcid.org/0000-0002-6137-2030","observed_orcids":["https://orcid.org/0000-0002-6137-2030","https://orcid.org/0009-0001-6682-4710"]},"institutions":[{"id":"https://openalex.org/I1325675289","display_name":"Moorfields Eye Hospital NHS Foundation Trust","ror":"https://ror.org/03zaddr67","country_code":"GB","type":"healthcare","lineage":["https://openalex.org/I1325675289"]},{"id":"https://openalex.org/I4210150574","display_name":"Moorfields Eye Hospital","ror":"https://ror.org/03tb37539","country_code":"GB","type":"healthcare","lineage":["https://openalex.org/I1325675289","https://openalex.org/I4210150574"]}],"countries":["GB"],"is_corresponding":true,"raw_author_name":"J Evans","raw_affiliation_strings":["Glaxo Department of Ophthalmic Epidemiology, Moorfields Eye Hospital and Institute of Ophthalmology, City Road, London EC1V 2PD, UK"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Glaxo Department of Ophthalmic Epidemiology, Moorfields Eye Hospital and Institute of Ophthalmology, City Road, London EC1V 2PD, UK","institution_ids":["https://openalex.org/I1325675289","https://openalex.org/I4210150574"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":2,"corresponding_author_ids":["https://openalex.org/A5091162454"],"corresponding_institution_ids":["https://openalex.org/I1325675289","https://openalex.org/I4210150574"],"apc_list":null,"apc_paid":null,"fwci":0.0,"has_fulltext":false,"cited_by_count":3,"citation_normalized_percentile":{"value":0.0,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":88,"max":93},"biblio":{"volume":"11","issue":"26","first_page":"26","last_page":"7"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11235","display_name":"Statistical Methods in Clinical Trials","score":0.9229000210762024,"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":0.9229000210762024,"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/T14374","display_name":"Statistical Methods in Epidemiology","score":0.04820000007748604,"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":0.01080000028014183,"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"}}],"keywords":[{"id":"https://openalex.org/keywords/randomized-controlled-trials","display_name":"randomized controlled trials","score":0.9860000014305115},{"id":"https://openalex.org/keywords/trial-design","display_name":"trial design","score":0.6759999990463257},{"id":"https://openalex.org/keywords/randomization","display_name":"randomization","score":0.7289999723434448},{"id":"https://openalex.org/keywords/blinding","display_name":"blinding","score":0.8709999918937683},{"id":"https://openalex.org/keywords/trial-ethics","display_name":"trial ethics","score":0.6159999966621399},{"id":"https://openalex.org/keywords/informed-consent","display_name":"informed consent","score":0.9459999799728394},{"id":"https://openalex.org/keywords/trial-sample-size","display_name":"trial size","score":0.5130000114440918},{"id":"https://openalex.org/keywords/statistical-power","display_name":"statistical power","score":0.6690000295639038},{"id":"https://openalex.org/keywords/confidence-intervals","display_name":"confidence intervals","score":0.4749999940395355},{"id":"https://openalex.org/keywords/hypothesis-testing","display_name":"hypothesis testing","score":0.5479999780654907},{"id":"https://openalex.org/keywords/type-i-error","display_name":"type I error","score":0.46299999952316284},{"id":"https://openalex.org/keywords/type-ii-error","display_name":"type II error","score":0.6840000152587891},{"id":"https://openalex.org/keywords/health-education","display_name":"health education","score":0.3059999942779541},{"id":"https://openalex.org/keywords/community-health-intervention","display_name":"community health intervention","score":0.35199999809265137},{"id":"https://openalex.org/keywords/publication-bias","display_name":"publication bias","score":0.42399999499320984},{"id":"https://openalex.org/keywords/selective-reporting-bias","display_name":"selective reporting","score":0.37700000405311584},{"id":"https://openalex.org/keywords/clinical-trial-registration","display_name":"clinical trial registration","score":0.3179999887943268},{"id":"https://openalex.org/keywords/consort","display_name":"CONSORT","score":0.35199999809265137},{"id":"https://openalex.org/keywords/cochrane-collaboration","display_name":"Cochrane Collaboration","score":0.4000000059604645},{"id":"https://openalex.org/keywords/meta-analysis","display_name":"meta-analysis","score":0.41600000858306885}],"concepts":[{"id":"https://openalex.org/C107130276","wikidata":"https://www.wikidata.org/wiki/Q133805","display_name":"Epidemiology","level":2,"score":0.705552875995636},{"id":"https://openalex.org/C71924100","wikidata":"https://www.wikidata.org/wiki/Q11190","display_name":"Medicine","level":0,"score":0.5350858569145203},{"id":"https://openalex.org/C168563851","wikidata":"https://www.wikidata.org/wiki/Q1436668","display_name":"Randomized controlled trial","level":2,"score":0.4578501284122467},{"id":"https://openalex.org/C512399662","wikidata":"https://www.wikidata.org/wiki/Q3505712","display_name":"Family medicine","level":1,"score":0.3870677351951599},{"id":"https://openalex.org/C126322002","wikidata":"https://www.wikidata.org/wiki/Q11180","display_name":"Internal medicine","level":1,"score":0.12615063786506653}],"mesh":[],"locations_count":3,"locations":[{"id":"pmid:17492029","doi":null,"is_oa":false,"landing_page_url":"https://pubmed.ncbi.nlm.nih.gov/17492029","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":"Community eye health","raw_type":"Journal Article"},{"id":"pmh:oai:pubmedcentral.nih.gov:1706053","doi":null,"is_oa":true,"landing_page_url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1706053/","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":"Community Eye Health","raw_type":"Text"},{"id":"mag:223998923","doi":null,"is_oa":false,"landing_page_url":"https://pubmed.ncbi.nlm.nih.gov/17492029","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":null,"is_accepted":false,"is_published":false,"raw_source_name":"PubMed","raw_type":null}],"best_oa_location":{"id":"pmh:oai:pubmedcentral.nih.gov:1706053","doi":null,"is_oa":true,"landing_page_url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC1706053/","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":"Community Eye Health","raw_type":"Text"},"sustainable_development_goals":[{"score":0.9391000270843506,"id":"https://metadata.un.org/sdg/3","display_name":"Good health and well-being"}],"study_designs":[],"awards":[],"funders":[],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":8,"referenced_works":["https://openalex.org/W1887056411","https://openalex.org/W2010418295","https://openalex.org/W2023091797","https://openalex.org/W2030192997","https://openalex.org/W2073025086","https://openalex.org/W2087425662","https://openalex.org/W2095413952","https://openalex.org/W2144504916"],"related_works":["https://openalex.org/W2018483067","https://openalex.org/W2480626694","https://openalex.org/W1488646325","https://openalex.org/W4382562443","https://openalex.org/W4214873960","https://openalex.org/W4241387990","https://openalex.org/W2078304184","https://openalex.org/W2021815358","https://openalex.org/W4410620507","https://openalex.org/W2766771398"],"abstract_inverted_index":{"Randomised":[0,201],"controlled":[1,103,114,227,644,781,1015],"trials":[2,63,429,771,782,831,860,882,950,968,1016],"are":[3,14,32,46,64,117,139,206,316,346,409,445,452,455,458,469,496,504,536,572,699,826,839,862,873],"the":[4,19,44,51,59,93,108,122,180,186,210,218,262,277,288,351,356,360,412,422,465,478,489,507,521,570,596,634,639,642,658,676,706,716,726,734,748,755,759,798,801,811,844,849,866,917,927,933,986,1018,1050],"most":[5,407,787],"straightforward":[6,471],"of":[7,22,53,87,95,111,135,155,159,192,199,212,222,282,291,355,414,428,434,464,523,552,598,601,610,663,715,728,736,750,783,791,800,813,830,832,848,852,898,926,939,962,988,1017,1020],"studies":[8,655,696],"to":[9,17,39,77,84,89,142,176,216,252,297,304,320,350,373,384,403,460,474,491,539,548,565,595,613,702,710,746,778,795,875,887,905,916,951,970,978,984,1000,1011,1025,1054],"design":[10,72,110,651,789],"and":[11,24,68,148,204,331,353,359,426,542,617,626,660,757,846,901,909,937,955,981,996,1024,1045],"interpret.":[12],"They":[13,376],"often":[15,37,207],"considered":[16,402],"be":[18,40,75,168,190,244,268,325,365,392,401,404,461,475,527,540,566,630,687,711,952],"\u2018gold\u2019":[20],"standard":[21],"clinical":[23,62,78,259,602],"epidemiological":[25,654],"studies.":[26],"This":[27,637,806,1030],"is":[28,36,82,234,239,257,302,311,342,417,430,484,515,530,558,562,587,591,612,622,638,646,679,709,720,766,773,794,804,807,816,822,855,883,919,969,994,998],"because,":[29],"if":[30,255,381,500,510,569,675,697],"they":[31,195,275,369,382,503],"conducted":[33,861],"properly,":[34],"it":[35,233,339,416,561,621,997],"possible":[38,83,1052],"fairly":[41,136],"sure":[42],"that":[43,232,264,323,344,362,380,421,443,454,483,493,533,797,838,858,877,913,1032],"results":[45,535,571,727,987],"correct,":[47],"at":[48],"least":[49,286],"for":[50,98,124,161,246,544,579,718,724,732,947,960,966,976],"type":[52],"patients":[54,138,205,318,332,345,444,980],"who":[55,172,761],"took":[56],"part":[57],"in":[58,224,394,437,501,517,769,819,835,865,921,945,1056],"study.":[60],"Good":[61],"almost":[65],"always":[66,670,808],"randomised":[67,102,113,226,643,695,780,1014],"controlled.":[69],"The":[70,157,786,894,935,991,1007],"study":[71,278,650,923],"need":[73,473,983],"not":[74,174,235,314,391,418,669,680,722,774,823],"limited":[76],"situations,":[79],"however.":[80],"It":[81,301,341,529],"investigate":[85],"questions":[86],"relevance":[88],"communities,":[90],"such":[91,647],"as":[92,313,349,701],"effect":[94,525,1019],"health":[96,283,388,892,1021,1037],"education,":[97],"example,":[99,125,162],"using":[100],"a":[101,112,129,200,225,265,294,306,309,321,432,511,518,556,648,775,792,899,958],"design.\r\n\r\nFigure":[104],"\u200bFigure11":[105],"sets":[106],"out":[107],"basic":[109],"trial.":[115],"There":[116,825],"many":[118],"good":[119,776,828],"textbooks":[120],"on":[121,272,657,843],"topic,":[123],"Pocock's":[126],"Clinical":[127],"trials:":[128],"practical":[130],"approach.1":[131],"A":[132,481],"sufficient":[133],"number":[134],"representative":[137],"randomly":[140],"allocated":[141,366],"two":[143,494,635],"or":[144,164,250,584,692,741,1042],"more":[145,240,537,563,767],"treatment":[146,178,194,215,223,238,310,322,357,363,451,524,616,704,802],"groups":[147,803],"followed":[149],"up":[150],"over":[151],"an":[152,247],"appropriate":[153],"period":[154],"time.":[156],"outcome":[158],"interest,":[160],"vision":[163],"visual":[165],"impairment,":[166],"should":[167,188],"measured":[169,681],"by":[170,911],"people":[171,408,580,888],"do":[173,305],"know":[175,985],"which":[177,193,237,273,586,703,815],"group":[179,705],"patient":[181,187,251,708,756,972],"was":[182],"allocated.":[183],"If":[184,555,620],"possible,":[185],"also":[189,378,431,731],"unaware":[191],"have":[196,334,942,956,1048],"received.\r\n\r\n\r\n\r\nFigure":[197],"1\r\n\r\nDesign":[198],"Controlled":[202],"Trial\r\n\r\n\r\n\r\nPhysicians":[203],"concerned":[208,410],"about":[209,337,450,891,1036],"ethics":[211,413],"withholding/":[213],"subjecting":[214],"half":[217],"patients.":[219,300],"Random":[220],"allocation":[221,609,799],"trial":[228,307,479,482,557,645,793,918],"requires":[229],"explicit":[230],"acknowledgement":[231],"known":[236,532,625,664],"effective;":[241],"this":[242,546,977],"may":[243,267,324,441,487,526,668],"difficult":[245,768,818,999],"individual":[248],"doctor":[249,274],"accept.":[253],"However,":[254],"there":[256],"no":[258],"consensus,":[260],"with":[261,293,411,1003],"result":[263,514],"person":[266,760],"treated":[269],"differently":[270],"depending":[271],"consult,":[276],"replaces":[279],"random":[280,608],"delivery":[281],"care":[284,389,1022],"(at":[285],"from":[287,754,758],"patient's":[289],"point":[290],"view),":[292],"positive":[295],"contribution":[296],"helping":[298],"future":[299],"better":[303],"when":[308],"new":[312],"only":[315,723],"fewer":[317,329],"exposed":[319],"dangerous,":[326],"but":[327,472,730,772],"also,":[328],"doctors":[330,982,1041],"will":[333,364,390,629],"strong":[335],"beliefs":[336],"whether":[338,1039],"works.":[340],"important":[343,788,857],"fully":[347],"informed":[348],"advantages":[352],"disadvantages":[354],"options,":[358],"fact":[361],"randomly,":[367],"before":[368,477],"give":[370],"their":[371,387,398,1057],"agreement":[372],"take":[374],"part.":[375],"must":[377],"understand":[379],"decline":[383],"participate":[385],"then":[386],"affected":[393],"any":[395,922],"way.":[396],"Otherwise,":[397],"consent":[399],"cannot":[400],"freely":[405],"given.\r\n\r\nWhilst":[406],"randomisation,":[415],"well":[419,531],"recognised":[420],"proper":[423],"design,":[424],"conduct":[425],"reporting":[427,961],"question":[433],"ethics;":[435],"weakness":[436],"these":[438,989,1027],"research":[439],"activities":[440],"mean":[442],"harmed":[446],"because":[447],"incorrect":[448],"conclusions":[449],"reached.\r\n\r\nTrials":[453],"too":[456,485],"small":[457,486,519,553],"likely":[459,538,564],"misleading.":[462],"Calculations":[463],"required":[466],"sample":[467],"size":[468],"relatively":[470],"done":[476],"begins.":[480],"lead":[488],"investigators":[490],"conclude":[492],"treatments":[495,744,752],"equally":[497,631],"effective,":[498,623],"even":[499,568],"reality":[502],"different.":[505],"On":[506],"other":[508,653],"hand,":[509],"statistically":[512],"significant":[513],"found":[516],"study,":[520],"estimate":[522],"exaggerated.":[528],"\u201csignificant\u201d":[534],"submitted":[541],"accepted":[543],"publication:":[545],"leads":[547],"publication":[549],"bias,":[550],"particularly":[551],"trials.2":[554],"large":[559],"enough":[560],"published,":[567],"negative.":[573],"Publication":[574],"bias":[575],"poses":[576],"serious":[577],"problems":[578],"undertaking":[581],"systematic":[582],"reviews":[583,1028],"meta-analyses":[585],"why":[588,641],"considerable":[589],"effort":[590],"now":[592],"being":[593],"devoted":[594],"development":[597],"complete":[599],"registers":[600],"trials.3\r\n\r\nThe":[603],"aim":[604,745],"behind":[605],"randomisation":[606,719],"(or":[607],"treatment)":[611],"produce":[614],"comparable":[615],"control":[618,671],"groups.":[619,636],"both":[624,753],"unknown":[627],"confounders\u2217":[628],"distributed":[632],"between":[633],"reason":[640,777,965],"powerful":[649],"-":[652],"depend":[656],"measurement":[659],"statistical":[661],"analysis":[662],"confounders.":[665],"Statistical":[666],"techniques":[667],"confounding":[672,677],"adequately,":[673],"especially":[674],"factor":[678],"very":[682,856],"well.4":[683],"Powerful":[684],"biases\u2217":[685],"can":[686,1047],"introduced":[688],"into":[689,694],"non-randomised":[690,739],"studies,":[691],"indeed":[693],"clinicians":[698],"aware":[700],"next":[707],"allocated.5":[712],"An":[713],"understanding":[714,733],"rationale":[717],"critical,":[721],"interpreting":[725,737],"trials,":[729,821],"problem":[735],"observational":[738],"studies.\r\n\r\nPlacebos":[740],"similar":[742],"looking":[743],"conceal":[747],"identity":[749],"different":[751,850],"assesses":[762],"outcome.":[763],"Such":[764],"masking":[765],"surgical":[770,784,820],"avoid":[779],"interventions.":[785],"feature":[790],"ensure":[796,876],"concealed.":[805],"possible.":[809],"Masking":[810],"assessment":[812],"outcome,":[814],"sometimes":[817],"essential.":[824],"several":[827],"examples":[829],"cataract":[833],"surgery":[834],"developing":[836],"countries":[837],"providing":[840],"useful":[841],"information":[842,914],"risks":[845],"benefits":[847],"types":[851],"intraocular":[853],"lenses.6\r\n\r\nIt":[854],"all":[859,878,948,1004],"reported":[863],"properly":[864],"medical":[867,930,992],"literature.":[868],"Several":[869],"international":[870],"collaborative":[871],"efforts":[872],"underway":[874],"data":[879],"collected":[880],"during":[881],"made":[884,953],"easily":[885],"available":[886,954,1049],"making":[889,1034],"decisions":[890,1035],"care.":[893,973],"CONSORT":[895],"statement":[896],"consists":[897],"checklist":[900],"flow":[902],"diagram,":[903],"intended":[904],"assist":[906,1055],"authors,":[907],"editors,":[908],"reviewers":[910],"ensuring":[912],"relevant":[915,1005],"included":[920],"report.7":[924],"Many":[925],"world's":[928],"major":[929],"journals,":[931],"including":[932],"BMJ,":[934],"Lancet,":[936],"Annals":[938],"Internal":[940],"Medicine,":[941],"joined":[943],"together":[944],"calling":[946],"unpublished":[949,963],"provided":[957],"mechanism":[959],"studies.\r\n\r\nThe":[964],"conducting":[967],"improve":[971],"In":[974],"order":[975],"happen,":[979],"trials.":[990],"literature":[993],"huge":[995],"keep":[1001],"up-to-date":[1002],"research.":[1006],"Cochrane":[1008],"Collaboration":[1009],"aims":[1010],"summa-rise":[1012],"systematically":[1013],"interventions,":[1023],"make":[1026],"accessible.":[1029],"means":[1031],"everyone":[1033],"care,":[1038],"patients,":[1040],"healthcare":[1043],"providers":[1044],"purchasers,":[1046],"best":[1051],"evidence":[1053],"choice.8":[1058]},"counts_by_year":[{"year":2025,"cited_by_count":1},{"year":2024,"cited_by_count":1},{"year":2016,"cited_by_count":1}],"updated_date":"2026-11-10T11:39:43.021295","created_date":"2016-06-24T00:00:00"}
