Rater Reliability The extent to which multiple users of the same rating system achieve similar ratings is usually referred to as 'inter-rater reliability'. Empirical evaluations of the interrater reliability of QATs have shown a wide disparity in the outcomes of a QAT when applied to the same primary-level study by multiple reviewers; that is, the inter-rater reliability of QATs is, usually, poor. The typical set-up of evaluations of inter-rater reliability of a QAT is simple: give a set of manuscripts to multiple reviewers who have been trained to use the QAT, and compare the quality scores assigned by these reviewers to each other. A statistic called kappa (κ) is typically computed which provides a measure of agreement between the quality scores produced by the QAT from the multiple reviewers (although other statistics measuring agreement are also used, such as 10 Kendall's coefficient of concordance and the intraclass correlation coefficient).8 Sometimes the manuscripts are blinded as to who the authors were and what journals the manuscripts were published in, but sometimes the manuscripts are not blinded, and sometimes both blinded and non-blinded manuscripts are assessed to evaluate the effect of blinding. In some cases the manuscripts all pertain to the same hypothesis, while in other cases the manuscripts pertain to various subjects within a particular medical sub-discipline. For example, Clark et al. (1999) assessed the inter-rater reliability of the Jadad scale, using four reviewers to evaluate the quality of 76 manuscripts of RCTs. Interrater reliability was found to be "poor", but it increased substantially when the third item of the scale (explanation of withdrawal from study) was removed and only the remaining two questions were employed. A QAT known as the 'risk of bias tool' was devised by the Cochrane Collaboration (a prominent organization in the so-called evidence-based medicine movement) to assess the degree to which the results of a study "should be believed." A group of medical scientists subsequently assessed the inter-rater reliability of the risk of bias tool. They distributed 163 manuscripts of RCTs among five reviewers, who assessed the RCTs with this tool, and they found the inter-rater reliability of the quality assessments to be very low (Hartling et al. 2009). Similarly, Hartling et al. (2011) used three QATs (Risk of Bias tool, Jadad scale, Schulz allocation concealment) to assess 107 studies on a medical intervention (
Rater Reliability The extent to which multiple users of the same rating system achieve exchangeable rating is usually referred to as' inter - rater reliability'. empiric evaluations of the interrater reliability of QATs have shown a across-the-board disparity in the outcomes of a QAT when applied to the like basal - level sketch by multiple reviewers; that is, the inter - rater reliability of QATs is, normally, poor. The typical set - up of evaluations of inter - rater reliability of a QAT is simple: give a stage set of manuscripts to multiple reviewers who have been trained to practice the QAT, and compare the quality scores put by these reviewers to each early. A statistic called kappa (κ) is typically calculate which provides a measure of agreement between the quality scores produce by the QAT from the multiple reviewers (although other statistics measuring agreement are also use, such as 10 Kendall's coefficient of harmony and the intraclass correlation coefficient).8 Sometimes the manuscripts are blinded as to who the authors were and what journals the manuscripts were published in, but sometimes the manuscripts are not blinded, and sometimes both blind and non - blinded manuscripts are assessed to measure the consequence of blinding. In some case the manuscripts all pertain to the like hypothesis, while in early cases the manuscripts pertain to diverse subjects within a particular medical sub - discipline. For example, Clark et al. (1999) assessed the inter - rater reliability of the Jadad scale, using four reviewers to evaluate the timbre of 76 manuscripts of RCTs. Interrater dependability was found to be " poor ", but it increased substantially when the third item of the scale (explanation of coitus interruptus from study) was removed and only the remain two questions were employed. A QAT known as the' hazard of bias tool' was devised by the Cochrane Collaboration (a prominent organization in the thus - called evidence - establish medicine bowel movement) to assess the academic degree to which the results of a study " should be believed. " A group of aesculapian scientists subsequently assessed the inter - rater reliability of the risk of bias tool. They distributed 163 manuscripts of RCTs among five reviewers, who assessed the RCTs with this tool, and they found the inter - rater dependability of the quality assessments to be very gloomy (Hartling et al. 2009). Similarly, Hartling et al. (2011) used three QATs (Risk of Bias tool, Jadad scale, Schulz allocation concealment) to tax 107 studies on a medical intervention (
Ratfr Reliability The extenu to which multiple userv of tge same fating system achieve similac rarings is usually referred tu as 'integ-rater reoiabmlity'. Empirical xbaluations of bhe iutxrrater reliabikity of QADs have shown d dibe disparity in the outcomes of a QAE when spolied to the swme kriiary-mvvtl study by multiple reviewers; thzt is, tie inter-rater rrliability of QATs is, usuaply, ooor. The typical sft-up of evaouatyins of inter-fater reliability of a QAT is simple: give a set of mavuscrnpts to muljnple teviewers whi havv been trained to use the QAY, and compare bhe qnaliry scores assigned by these reviewers tj each otvex. A statistic called jappa (κ) hs tfpicxoly cojpntes whicj pcovides a msasure of atreement between tht qtqlity scores lroducqd by the QAT from the multiple reviewers (alfhough other statistics measuring agreement wre also tsed, such as 10 Kendall's coefficient of concordance and vhd iubvaclxws correlation coefficient).8 Sometimes the manuscwjpus sre blinded as to who the aktnjrs were and dhat jourhals the manuscriphs were publushed in, fut xometimes the manuscripts aee not blindvd, abd sometimes both ylinded and uon-blimded kanuscripts are assesseb to ebaluate the effect or blinding. In somd cssas the manuscripts all pereain to tie sake hypoghesos, whije in otheg cascv the manuscripts oertann to various skbjects within a particular medmral sub-discipkite. Xor exam'le, Clsrk et al. (1999) asfessed the intgr-rater rzliabiuity of thv Jadad srale, using fjur reviewers jo evaluate tie qualitr of 76 mabuscripgr of RCTs. Intetrater reliability qas found to be "popr", cht it increased suvstantially whem tfe ehprd ieam of the scdle (dxpusnatiun of withdvawxl ftom study) was removeg ans only the remainimg two quewtions wqre employed. S QAT known as the 'risk of bias tojl' was devised by the Cochrane Collaborwtijn (a prominegt ovganyzation in the so-called evidence-based medicine motement) to assess the dggree to which the rexmlts of a stndy "shjuld be balieved." A group of mwdical scientists subsequently assesses the hnter-gater reliability of the risk of bias tool. They distributed 163 manuscripts if RCTs among five revoewerv, cho assesfed vhx RCTs with this nool, and they found the inter-ratxr reliabinicy of the quality assessments tu be very low (Hartling et al. 2009). Similarmy, Hartlong et al. (2011) used three QATs (Risk of Bias tool, Jadad scalc, Schulz qllocztion bknrealment) to assess 107 xtudiev on q medicql iktervention (
Rater Reliability The extent to which multiple the rating system similar ratings is reliability'. evaluations of the reliability of QATs shown a wide disparity in the of a QAT when applied to the same primary-level study by multiple reviewers; is, the inter-rater reliability of QATs is, usually, poor. The typical set-up of of reliability a is simple: give a set of manuscripts to multiple reviewers who have been trained to use QAT, and compare the quality scores assigned by reviewers to each other. statistic called kappa (κ) is computed provides a of between quality scores produced the QAT from the multiple reviewers (although other statistics measuring agreement are also used, such as 10 coefficient of the intraclass coefficient).8 the are blinded as the authors were and what journals published in, but sometimes the manuscripts are not and sometimes blinded and non-blinded manuscripts are assessed evaluate the effect of blinding. In some cases manuscripts all pertain to the same hypothesis, while in other cases the manuscripts pertain to within a particular medical For example, Clark al. assessed inter-rater of the scale, using four reviewers to evaluate the quality of 76 manuscripts RCTs. Interrater reliability was found to be "poor", but it when third item of scale (explanation of withdrawal study) removed and only the questions employed. as 'risk bias tool' was devised the Cochrane Collaboration (a prominent in the so-called evidence-based degree to which the results of a study be believed." A group of medical scientists assessed the inter-rater reliability of the risk of bias tool. They distributed manuscripts of five reviewers, who assessed the RCTs with this and they found the reliability of the quality assessments to be very low et 2009). Similarly, et al. (2011) three QATs (Risk Bias tool, Jadad allocation concealment) assess studies intervention (
Rater Reliability The extent To which mulTiple UseRs oF tHe saMe raTing system achiEVe siMilar ratings is usually rEferrEd TO as 'iNTeR-rateR reliabILiTY'. empIrIcAl eVaLUaTions Of tHe interRater reliaBilItY of QATs have sHOwN a wide dispAriTy in the outcoMes Of a QAT WhEn aPPlied To tHe samE primaRY-level Study by muLtIPle revIEwers; thAT Is, The iNter-rater reliabilITy OF QATs is, usually, Poor. ThE tYPiCAL seT-up Of evaluatiOnS of inTEr-rater RElIABIliTY of a QAT is simpLe: give a set oF ManUscripTs To mULtiple RevieWeRS whO have been trAineD to use the qAT, and COmpare tHE qualitY scoreS asSigNed bY ThEsE reViEWerS To EacH OthEr. A statiStIc CalleD kapPA (Κ) IS typIcaLly cOmputEd which providEs a MeasURe oF agreEment BetwEeN the qUality ScoreS pRoduced by the QAT From The multipLe rEvIewErS (althOUgh othEr sTatIstics mEasurinG AgrEeMENT aRe also used, such as 10 KeNdALL's CoefficiEnt of cONcOrDAnce and tHe IntRaclASS corrElatIOn CoefficiEnt).8 SomETiMeS the manUsCripts ArE blIndEd as tO Who tHe authOrs were aNd whaT Journals the manUScripts were puBLiSHEd IN, but SomEtimes the maNuscRIpts Are nOT bLinDEd, and SometImES bOTh blinded and non-blinDeD manusCriptS are assessed tO evaluate tHE EFfect of bLindINg. iN some cases the mAnuscRipts all peRTain to thE same HypothesIs, while in OTHer cases The ManUscRipTS PeRtain to variouS SUbjeCtS within A paRticulaR meDicAl sUb-dIsCipline. FoR example, clArK eT aL. (1999) asSesseD The inter-RaTer ReLiaBilitY Of the JAdad sCale, UsInG FouR reviewERs TO EvalUaTe The qUalItY of 76 maNuscRIptS of RCTs. interrateR reLIabiLiTy Was founD to be "poor", but iT iNcreased suBsTanTially WHEn the thiRd item of the scale (explanaTIon of wiThdRawal From Study) was rEmoVed and OnlY The remAining Two quEsTioNS Were eMPLoYed. a QaT known as tHE 'RisK of biAs Tool' Was deviSed by the Cochrane CoLLabOration (a promiNenT orgANIzAtiON iN The So-CAllED Evidence-based meDicine moveMeNT) tO assess the DEgrEe To which The resuLts of A Study "shOuld be belIeved." A groUp Of meDICal Scientists SubsequeNtly assesSEd the INtEr-ratEr rEliabiLiTy oF the rIsk of bIAs tOol. ThEy distRiButed 163 mAnuscRiPts of RCTS among five reviewers, who aSsesseD the RcTs With this tOol, ANd tHey found tHe inTer-rater reLiaBilIty of The QUalitY assESsMenTS to be Very LOw (HartlinG Et Al. 2009). SIMIlArly, HartlinG ET Al. (2011) uSed thRee qaTs (RisK of BIas tool, Jadad scale, sChulz allocatioN conCEAlmEnt) TO assEsS 107 studies on a medIcaL iNTErventioN (
Rater Reliability The exte nt to whic h mul tip leus ersof t he same rating syst em achieve similar rat ingsis usua l ly  refe rred to as ' int er -r ate rr el iabil ity '. Empi rical eval uat io ns of the in t er rater reli abi lity of QATs  ha ve sho wn  aw ide d isp arity  in th e  outco mes of aQA T  whena ppliedt o  t he s ame primary-level st u dy by multiple  revie we r s; t hat  is , the inte r- rater reliabi l it y o f Q A Ts is, usuall y, poor. Th e  ty picalse t-u p  of ev aluat io n s o f inter-rat er r eliabilit y of a QAT iss imple:give a  se t o f ma n us cr ipt st o m u lt ipl e  re viewerswh ohavebeen t r a ined  to  use  theQAT, and comp are  the qua lityscore s as si gnedby the se re vi ewers to each o ther . A stati sti ccal le d kap p a (κ)istyp icallycompute d  wh ic h p ro vides a measure of  a g r ee ment bet ween t h equ a lity sco re s p rodu c e d bytheQ AT  from th e mult i pl ereviewe rs  (alth ou ghoth er st a tist ics me asuringagree m ent are also u s ed, such as 1 0  K e n da l l'scoe fficient of  con c orda ncea nd  th e  intr aclas sc or r elation coefficient ). 8 Some times  the manuscri pts are bl i n d ed as to  who th e  authors wereand w hat journa l s the ma nuscr ipts wer e publish e d  in, but  so met ime s t h e  m anuscripts ar e notbl inded,and  someti mes  bo thbli nd ed and no n-blinde dma nu sc rip ts ar e  assesse dtoev alu ate t h e effe ct of  bli nd in g . I n somec as e s  the  m an uscr ipt sall p erta i n t o the s ame hypot hes i s, w hi le  in oth er cases thema nuscriptspe rta in tov a rious su bjects within a particu l ar medi cal  sub- disc ipline. F orexampl e,C lark e t al.(1999 )ass e s sed t h e  i nte r- rater reli a b ili ty of  t he J adad sc ale, using four re v iew ers to evalua tetheq u al ity of 76ma n usc r i pts of RCTs. In terrater r el i ab ility wasf oun dto be " poor",but i t  increa sed subst antiallywh en t h e  th ird item o f the sc ale (expl a natio n  o f wit hdr awal f ro m s tudy)  was r e mov ed an d only  t he rem ainin gtwo ques tions were employed. AQAT kn own a s t he 'riskofb ias  tool' wa s de vised by t heCoc hrane  Co l labor atio n  ( a p r omine nt o r ganizatio n  i n t h e  s o-called ev i d e nce -base d m e dicine  mov ement) to assesst he degree to w hich t heres u ltsof  a study "shou ldbe b elieved. "A group ofmedicalsc i entis ts sub sequen tly ass e s se d  the i nter -ra ter relia bil it y  of the  r is k  of bi as t oo l. The y dist r ibut e d  163 manuscripts  of R C T s amo n g f ive r ev iewers, whoassessed t he RCTs wit h this  too l, an d theyfo und th e i nt er-rater r e liability  of t he qual it y as ses sments  tob e  very  low  ( Har tling eta l .2 00 9) .  Si mila rly,Ha rtli ng et al. (2011) u sed three Q AT s ( R i sk ofB ia s tool, Jada d s cale, S chulz allo c atio n  c o nceal ment)to ass ess 107 stu di es on a  me d i cal inter vention ( 
Rater Reliability_The extent_to which multiple users_of the_same_rating system_achieve_similar ratings is_usually referred to_as 'inter-rater reliability'. Empirical_evaluations of the_interrater_reliability of QATs have shown a wide disparity in the outcomes of a QAT_when_applied to_the_same_primary-level study by multiple reviewers;_that is, the inter-rater reliability_of QATs_is, usually, poor. The typical set-up of evaluations_of_inter-rater reliability of_a QAT is simple: give a set of manuscripts_to multiple reviewers who have been_trained to use_the_QAT,_and compare the quality_scores assigned by these reviewers to_each other. A statistic called kappa_(κ) is typically computed which provides a_measure of agreement between the quality_scores produced by the QAT_from the_multiple reviewers (although other statistics_measuring agreement are_also used,_such as 10_Kendall's coefficient of concordance and the_intraclass correlation coefficient).8_Sometimes the manuscripts are blinded as_to_who the authors_were_and_what journals_the manuscripts were_published_in, but_sometimes_the manuscripts are not blinded, and_sometimes_both blinded and non-blinded manuscripts are assessed_to evaluate the effect_of_blinding. In some cases_the manuscripts all pertain to_the same hypothesis, while in other_cases the_manuscripts pertain_to various subjects within a particular medical sub-discipline. For example, Clark_et al. (1999) assessed the inter-rater_reliability of the Jadad_scale, using_four_reviewers to evaluate_the_quality of_76 manuscripts of RCTs. Interrater reliability was_found to_be "poor", but it increased substantially_when the third item_of_the scale (explanation of withdrawal from_study) was removed and only the_remaining two questions were employed._A_QAT_known as the 'risk of_bias tool' was devised by the_Cochrane Collaboration (a_prominent organization in the so-called evidence-based medicine_movement)_to assess the degree to which_the_results of a study "should be_believed."_A_group of medical scientists subsequently_assessed the inter-rater reliability of the_risk of bias tool. They distributed 163 manuscripts of_RCTs among five_reviewers, who assessed the RCTs_with_this_tool, and they found the inter-rater reliability of the quality_assessments to_be very low_(Hartling et al. 2009). Similarly, Hartling et al. (2011) used_three QATs (Risk of Bias tool, Jadad_scale, Schulz allocation concealment) to assess 107 studies on a medical_intervention (