cochrane評分表

1、Risk of biasItemAuthorsDescriptionjudgementAdequateYesPrinicipalauthor statedthatsequencecomputer generatedgeneration?allocation was usedAllocationYesPrinicipalauthor statedthatconcealment?allocation was concealedBlinding?UnclearNo mention of study personnelor participants being blindto treatment gr

2、oupIncompleteYesAll participants accountedoutcome datafor, one drop out recordedaddressed?but includedby us in analysisFree of otherUnclearPossible uneven distributionbias?of complete and incompleteparalysis at start of studybetween the two treatmentgroupsCochrane RCT 質(zhì)量評價標準：隨機方法是否正確。是否隱蔽分組。盲法的使用情況。

3、失訪或退出描述情況，有無采用意向性(ITT) 分析。以上質(zhì)量標準中,如所有標準均為“充分 ”,則發(fā)生各種偏倚的可能性很??；如其中一條為不清楚, 則有發(fā)生相應(yīng)偏倚的中等度可能性；如其中一條為“不充分 ”或“未采用 ”,則有發(fā)生相應(yīng)偏倚的高度可能性?？蓞⒁姡篟CT 的質(zhì)量評價標準選擇總結(jié)/bbs/topic/18137535?tpg=1&age=-1Quality assessmentThe quality of the trials was assessed and graded independently by two authors according to

4、the criteria described in The Cochrane Handbook 4.2.6 ( Higgins 2006 ). Gradings were compared and any inconsistencies between the authors in the interpretation of inclusion criteria and their significance to the selected study were discussed and resolved.The selected study was assessed for the foll

5、owing characteristics:1. The adequacy of the randomisation process (possible selection bias). Adequate randomisation includes any one of the following methods: computer generated or table of random numbers, drawing of lots, coin-toss, shuffling cards or throw of a dice. Inadequate methods of randomi

6、sation include the following: case record number, date of birth or alternate numbers.2. The adequacy of the allocation concealment (possible selection bias). Adequate methods of allocation concealment include either central randomisation (i.e. separate to other aspects of trial administration) or se

7、quentially numbered sealed opaque envelopes. Inadequate concealment means an open allocation sequence in which either participants or trialists were able to foresee the upcoming assignment.3. The blinding of outcome assessors (i.e. whether the persons assessing the outcome of care were aware of whic

8、h treatment the participant had received - possible performance bias).4. The extent and handling of losses to follow up (possible attrition bias). Adequate handling of losses to follow up involves a clear description and explanation being given of any significant difference between the losses of the

9、 intervention groups. An unacceptable loss in any one intervention group was considered to be loss greater than 20%.Study gradings A, B or C were employed for overall quality as follows.A: Minimisation of bias inall four categories above: i.e. adequate randomisation, few losses tofollow up and inten

10、tion-to-treat analysis, blinding of outcome assessors, high quality outcome assessment;B: Each of the criteria in A partially met;C: One or more of the criteria in A not met.Risk of bias in included studiesWe classified this study as grade C because of the uncertainty about blinding. The possibility

11、 of an uneven distribution of complete andincomplete palsies between the two groups is another potential source of bias and we conclude overall that this is a low quality study.Table 8.5.a: The Cochrane Collaborations tool for assessingrisk of biasDomainDescriptionReview authors judgementSequenceDes

12、cribe the method used toWas the allocationgeneration.generate the allocation sequencesequence adequatelyin sufficient detail to allow angenerated?assessment of whether it shouldproduce comparable groups.AllocationDescribe the method used toWas allocationconcealment.conceal the allocation sequenceade

13、quately concealed?in sufficient detail to determinewhether intervention allocationscould have been foreseen inadvance of, or during, enrolment.Blinding ofDescribe all measures used, ifWas knowledge of theparticipants,any, to blind study participantsallocated interventionpersonnel andand personnel fr

14、om knowledge ofadequately preventedoutcomewhich intervention a participantassessorsreceived. Provide any informationAssessmentsrelating to whether the intendedshould be made forblinding was effective.each main outcome(or class ofoutcomes).IncompleteDescribe the completeness ofoutcome dataoutcome dat

15、a for each mainAssessmentsoutcome, including attrition andshould be made forexclusions from the analysis.each main outcomeState whether attrition and(or class ofexclusions were reported, theoutcomes).numbers in each interventiongroup (compared with totalrandomized participants),reasons for attrition

16、/exclusionswhere reported, and anyre-inclusions in analysesperformed by the review authors.Selective outcomeState how the possibility ofreporting.selective outcome reporting wasexamined by the review authors,and what was found.Other sources ofState any important concernsbias.about bias not addressed

17、 in theother domains in the tool.If particular questions/entrieswere pre- specified in the reviewprotocol, responses should beprovided for each question/entry.during the study?Were incomplete outcome data adequately addressed?Are reports of the study free of suggestion of selective outcome reporting

18、?Was the study apparently free of other problems that could put it at a high risk of bias? sTable 8.5.c: Criteria for judging risk of bias in theRisk of biasassessment toolThe investigators describe a non-random component in NOthe sequence generation process. Usually, thedescription would involve so

19、me systematic, non-random approach, for example:Sequence generated by odd or even date of birth; Sequence generated by some rule based on date (or day) of admission;Sequence generated by some rule based on hospital or clinic record number.Other non-random approaches happen much less frequently than

20、the systematic approaches mentioned above and tend to be obvious. They usually involve judgement or some method of non-random categorization of participants, for example:Allocation by judgement of the clinician; Allocation by preference of the participant;Allocation based on the results of a laborat

21、ory test or a series of tests;Allocation by availability of the intervention.Criteria for the judgement of (i.e. high risk of bias).SEQUENCE GENERATIONWas the allocation sequence adequately generated? Short form:Adequate sequence generation?Criteria for aThe investigators describe a random component

22、 in thejudgement of YESsequence generation process such as:(i.e. low risk of bias).Referring to a random number table;Using a computer random number generator; Coin tossing;Shuffling cards or envelopes; Throwing dice;Drawing of lots; Minimization*.*Minimization may be implemented without a random el

23、ement, and this is considered to be equivalent to being random.Criteria for thejudgement ofInsufficient information about the sequence generationprocess to permit judgement of Yes or No . UNCLEAR (uncertain risk of bias).ALLOCATION CONCEALMENTWas allocation adequately concealed? Short form:concealme

24、nt?AllocationCriteria for aParticipants and investigators enrolling participants couldjudgement of YESnot foresee assignment because one of the following, or (i.e. low risk of bias). an equivalent method, was used to conceal allocation:Central allocation (including telephone,web-based, and pharmacy-

25、controlled,randomization);Sequentially numbered drug containers of identicalappearance;Sequentially numbered, opaque, sealedenvelopes.Criteria for theParticipants or investigators enrolling participants couldjudgement of NOpossibly foresee assignments and thus introduce(i.e. high risk ofselection bi

26、as, such as allocation based on:bias).Using an open random allocation schedule (e.g. alist of random numbers);Assignment envelopes were used withoutappropriate safeguards (e.g. if envelopes wereunsealed or nonopaque or not sequentiallynumbered);Alternation or rotation;Date of birth;Case record numbe

27、r;Any other explicitly unconcealed procedure.Criteria for theInsufficient information to permit judgement of Yes orjudgement of No . This is usually the case if the method of UNCLEARconcealment is not described or not described in(uncertain risk ofsufficient detail to allow a definite judgementforbi

28、as).example if the use of assignment envelopes is described,but it remains unclear whether envelopes weresequentially numbered, opaque and sealed.BLINDING OF PARTICIPANTS, PERSONNEL AND OUTCOMEASSESSORSWas knowledge of the allocated interventions adequately preventedduring the study? Short form:Blin

29、ding ?Criteria for aAny one of the following:judgement of YESNo blinding, but the review authors judge that the(i.e. low risk of bias).outcome and the outcome measurement are notlikely to be influenced by lack of blinding;Blinding of participants and key study personnelensured, and unlikely that the

30、 blinding could havebeen broken;Either participants or some key study personnelwere not blinded, but outcome assessment wasblinded and the non-blinding of others unlikely tointroduce bias.Criteria for theAny one of the following:judgement of NONo blinding or incomplete blinding, and the(i.e. high ri

31、sk ofoutcome or outcome measurement is likely to bebias).influenced by lack of blinding;Blinding of key study participants and personnelattempted, but likely that the blinding could havebeen broken;Either participants or some key study personnelwere not blinded, and the non-blinding of otherslikely

32、to introduce bias.Criteria for theAny one of the following:judgement ofInsufficient information to permit judgement of UNCLEAR Yes or No ;(uncertain risk ofThe study did not address this outcome.bias).INCOMPLETE OUTCOME DATAWere incomplete outcome data adequately addressed? Short form:Incomplete out

33、come data addressed?For dichotomous outcome data, the proportion of missing outcomes compared with observed event risk enough to induce clinically relevant bias in intervention effect estimate;For continuous outcome data, plausible effect size (difference in means or standardized difference in means

34、) among missing outcomes enough to induce clinically relevant bias in observed effect size; As-treated analysis done with substantial departure of the intervention received from that assigned at randomization;Potentially inappropriate application of simple imputation.Criteria for aAny one of the fol

35、lowing:judgement of YESNo missing outcome data;(i.e. low risk of bias).Reasons for missing outcome data unlikely to berelated to true outcome (for survival data,censoring unlikely to be introducing bias);Missing outcome data balanced in numbers acrossintervention groups, with similar reasons formiss

36、ing data across groups;For dichotomous outcome data, the proportion ofmissing outcomes compared with observed eventrisk not enough to have a clinically relevant impacton the intervention effect estimate;For continuous outcome data, plausible effect size(difference in means or standardized difference

37、 inmeans) among missing outcomes not enough tohave a clinically relevant impact on observed effectsize;Missing data have been imputed using appropriatemethods.Criteria for theAny one of the following:judgement of NOReason for missing outcome data likely to be(i.e. high risk ofrelated to true outcome

38、, with either imbalance inbias).numbers or reasons for missing data acrossintervention groups;Criteria for theAny one of the following:judgement ofInsufficient reporting of attrition/exclusions to UNCLEARpermit judgementof Yes or No (e.g. number(uncertain risk ofrandomized not stated, no reasons for

39、 missingbias).data provided);The study did not address this outcome.SELECTIVE OUTCOME REPORTINGAre reports of the study free of suggestion of selective outcomereporting? Short form:Free of selective reporting?Criteria for aAny of the following:judgement of YESThe study protocol is available and all

40、of the(i.e. low risk of bias).study s pre-specified (primary and secondary)outcomes that are of interest in the review havebeen reported in the pre-specified way;Criteria for the judgement of (i.e. high risk of bias).The study protocol is not available but it is clear that the published reports incl

41、ude all expected outcomes, including those that were pre-specified (convincing text of this nature may be uncommon).Any one of the following: NONot all of the study-specifiedpre primaryoutcomes have been reported;One or more primary outcomes is reported using measurements, analysis methods or subset

42、s of the data (e.g. subscales) that were not pre-specified;One or more reported primary outcomes were not pre-specified (unless clear justification for their reporting is provided, such as an unexpected adverse effect);One or more outcomes of interest in the review are reported incompletely so that

43、they cannot be entered in a meta-analysis;The study report fails to include results for a key outcome that would be expected to have been reported for such a study.Criteria for theInsu fficient information to permit judgement of Yes orjudgement of No . It is likely that the majority of studies will

44、fall into this UNCLEARcategory.(uncertain risk ofbias).OTHER POTENTIAL THREATS TO VALIDITYWas the study apparently free of other problems that could put it at a risk of bias? Short form: Free of other bias ?Criteria for aThe study appears to be free of other sources of bias.judgement of YES(i.e. low

45、 risk of bias).Criteria for theThere is at least one important risk of bias. For example,judgement of NOthe study:(i.e. high risk ofHad a potential source of bias related to thebias).specific study design used; orStopped early due to some data-dependentprocess (including a formal-stopping rule); orH

46、ad extreme baseline imbalance; orHas been claimed to have been fraudulent; orHad some other problem.Criteria for theThere may be a risk of bias, but there is either:judgement ofInsufficient information to assess whether an UNCLEARimportant risk of bias exists; or(uncertain risk ofInsufficient ration

47、ale or evidence that an identifiedbias).problem will introduce bias.Figure 8.6.a: Example of aRisk of bias table for a single study(fictional)EntryJudgementDescriptionAdequate sequenceYes.Quote:“ patients were randomly allocated.”generation?Comment: Probably done, since earlier reportsfrom the same

48、investigators clearly describe use ofrandom sequences (Cartwright 1980).Allocation concealment?No.Quote: “ .using a table of random numbers.”Comment: Probably not done.Blinding? (Patient-reportedYes.Quote:“ double blind, double dummy” ;“ High andoutcomes)low dose tablets or capsules were indistinguishablein all aspects of their outward app