偏倚类型 选择偏倚 随机序列的产生 判断指标 评价员的判断 分配隐藏 足够详细的描述用于生成分配序列的方法，以评估产生的分组是否具有可比性。 足够详细的描述隐藏分配序列的方法，以决定干预的分配在纳入之前或纳入过程中是否可见 生成随机序列不充分，发生选择偏倚 分配前分配隐藏不充分发生选择偏倚 实施偏倚 实施者和参与者如果有，描述对参与者和实施者行双盲 应对每个主盲法，避免其了解干预信息的所有要结局进行评估措施。提供任何与所实施的盲法是（或分类结局）? 否有效地相关信息。 测量偏倚 结局评估中的盲如果有，描述对结局者行盲法，避法 每个主要结局免其了解自己所接受的干预信息均应评估（或分类的所有措施。提供任何与所实施的结局） 盲法是否有效地相关信息。 失访偏倚 不全结局数据每描述每个主要结局数据的完整性，个主要结局均应包括分析中的自然缺失和排除。这评估（或分类结些缺失数据是否报告，在各个干预局） 组的数目（并与总样本量比较），数据缺失以及重新纳入分析的原因 发表偏倚 Selective 说明如何审查选择性报道结局的reporting. 可能性，以及审查结果 其它偏倚 其它偏倚来源 说明不包括在上述偏倚中的其它重要偏倚 参与者和实施者了解干预的相关信息导致实施偏倚 结局评估者了解分配的干预措施将导致测量偏倚 不全结局数据的数量，性质，处理方式导致失访偏倚 选择性报道结局导致发表偏倚 不包括在上述各项中的偏倚 如果特定的问题或条目事先在计划书中指出，应对每一项说明 随机序列的产生 随机序列产生不充分导致选择偏倚 判断为低风险的标准 研究者描述随机序列产生过程譬如: 参考随机数字表 • 使用计算机随机数字生成器 • 扔硬币 • 洗牌的卡片和信封 • 掷骰子 • 抽签 • 最小化 • *最小化，可实现无随机元素，被认为相当于是随机的。 判断为高风险的标准 研究者描述序列的产生使用的是非随机的方法。通常是系统的非随机方法，例如： 通过奇偶或出生日期产生序列 • 通过入院日期产生序列 • 通过类似住院号或门诊号产生序列? • 相对于上面提到的系统方法，其它非随机的方法少见的多，也更明显。通常包括对参与者进行判断或非随机的方法，例如: 临床医生判断如何分配 • 参与者判断如何分配 • 基于实验室检查或系列测试的结果分配 • 基于干预的可获取性进行分配 • 偏倚风险不清楚的判断标准 没有足够的信息判断随机序列的产生存在高风险或低风险 分配隐藏 分配前不充足的分配隐藏导致选择偏倚 低风险判断标准 参与者以及纳入参与者的研究者因以下掩盖分配的方法或相当的方法，事先不了解分配情况 中心分配（包括电话，网络，药房控制随机） • 相同外形的顺序编号的药物容器； • 顺序编号、不透明、密封的信封 • 高风险判断标准 参与者以及纳入参与者的研究者可能事先知道分配，因而引入选择偏倚，譬如基于如下方法的分配: • • • • • 使用摊开的随机分配表（如随机序列清单） 分发信封但没有合适的安全保障（如透明、非密封、非顺序编号） 交替或循环 出生日期 病历号 • 其它明确的非隐藏过程 风险未知 没有足够信息判断为低风险或高风险。通常因分配隐藏的方法未描述或描述不充分。例如描述为使用信封分配，但为描述信封是否透明？密封？顺序编号？ 对参与者和实施者的盲法 因参与者和实施者了解干预情况而导致实施偏倚 偏倚低风险标准 任何如下标准: 无盲法或盲法不充分，但系统评价员判断结局不太可能受到缺乏盲法的影响 • 参与者和主要实施者均实施可靠的盲法，且盲法不太可能被打破 • 偏倚高风险标准 任何如下标准: 无盲法或盲法不充分，但系统评价员判断结局很可能受到缺乏盲法的影响 • 尝试对关键的参与者和实施者行盲法，但盲法很可能被打破，结局很可能受到缺乏盲法的影响 • 风险未知 任何如下标准: 没有足够信息判断为低风险或高风险 • 研究未描述此情况 • 对结局评价实施盲法 结局评价者了解干预分配信息将导致测量偏倚 偏倚低风险标准 任何如下标准: 无盲法或盲法不充分，但系统评价员判断结局不太可能受到缺乏盲法的影响 • 参与者和主要实施者均实施可靠的盲法，且盲法不太可能被打破 • 高风险判断标准 任何如下标准: 无盲法或盲法不充分，但系统评价员判断结局很可能受到缺乏盲法的影响 • 尝试对关键的参与者和实施者行盲法，但盲法很• 可能被打破，结局很可能受到缺乏盲法的影响 风险未知 任何如下标准: 没有足够信息判断为低风险或高风险 • 研究未描述此情况 • 结局数据不完整 不全结局数据的数量，性质，处理方式导致失访偏倚 偏倚低风险标准 任何如下标准: • • • • • • 无缺失数据 缺失数据的产生不大可能与真实结局相关（对于生存数据，删失不大可能引入偏倚） 缺失数据的数目在各干预组相当，且各组缺失原因类似 对二分类变量，与观察事件的发生风险相比，缺失比例不足以影响预估的干预效应 对连续性结局数据，缺失数据的合理效应规模（均数差或标准均数差）不会大到影响观察的效应规模; 缺失的数据用合适的方法进行估算 高风险判断标准 任何如下标准: • • • • • 缺失数据的产生很大可能与真实结局相关, 缺失数据的数目及缺失原因在各干预组相差较大 对二分类变量，与观察事件的发生风险相比，缺失比例足以影响预估的干预效应 对连续性结局数据，缺失数据的合理效应规模（均数差或标准均数差）足以影响观察的效应规模; 意向治疗分析中存在实际干预措施与随机分配的干预相违背的情况 对缺失数据进行简单的不合适的估算 风险未知 任何如下标准: 没有报道缺失或排除的情况，无法判断高风险或低风险（如未说明随机的数量，未提供数据缺失的原因） • 研究未描述此情况 • 选择性发表 选择性发表导致发表偏倚 偏倚低风险标准 任何如下标准: 实验的计划书可获取，系统评价感兴趣的所有首要或次要结局均按计划书预先说明的方式报道 • 实验计划书不可得，但很明显发表的报告包括所有的结局，包括预先说明的结局（这种性质的有说服力的文字可能少见） • 高风险判断标准 任何如下标准: 不是所有的预先说明的首要结局均被报道 • 一个或多个首要结局为采用预先说明的测量方法、分析方法或数据子集来报道 • 系统评价感兴趣的一个或多个首要结局报道不全，以至于不能纳入meta分析 • 研究未报道此研究应当包含的主要关键结局 • 风险未知 没有足够信息判断高风险或低风险，貌似大部分研究会被分为此类 OTHER BIAS? 不包括在以上五种的其它偏倚 偏倚低风险标准 研究应未引入其它来源的偏倚 高风险判断标准 至少有一种重要的偏倚风险，例如： 具有与特殊试验设计相关的潜在偏倚来源 • 或被指欺诈 • 或其它问题 • 风险未知 可能存在偏倚风险，但存在以下两种中的一种 没有足够信息评估是否存在其它重要的偏倚风险 • 没有足够的证据认为发现的问题会引入偏倚 • Possible approach for summary assessments of the risk of bias for each important outcome (across domains) within and across studies Risk of bias Low risk of bias. 解释 合理的偏倚不太可能严重改变结果 Unclear risk of 合理的偏倚会对bias. 结果产生一定的怀疑 High risk of 偏倚严重削弱结bias. 果的可信度 对单个研究 每一类偏倚均为低风险 一类或多类偏倚风险未知 一类或多类偏倚为高风险 对多个研究整体 绝大多数信息均来自偏倚低风险的研究 绝大多数信息均来自偏倚低风险或风险未知的研究 来自高偏倚风险研究的信息比例足以影响结果的解释 英文：
Table
Domain Selection bias. Random sequence generation. Support for judgement Review authors’ judgement the allocation sequence in sufficient it should produce comparable groups. allocation to interventions) of a randomised sequence. Selection bias (biased allocation to interventions) Describe the method used to generate Selection bias (biased detail to allow an assessment of whether due to inadequate generation Allocation concealment. Describe the method used to conceal the allocation sequence in sufficient detail to determine whether intervention due to inadequate allocations could have been foreseen in concealment of allocations advance of, or during, enrolment. Performance bias. Blinding of participants and personnel be made for each main outcome (or class of outcomes).? Detection bias. prior to assignment. Describe all measures used, if any, to Performance bias due to blind study participants and personnel knowledge of the allocated from knowledge of which intervention a interventions by participants and personnel during the study. information relating to whether the intended blinding was effective. Assessments should participant received. Provide any blind outcome assessors from participant received. Provide any Detection bias due to knowledge of the allocated interventions by outcome Blinding of outcome Describe all measures used, if any, to assessment be made for each Assessments should knowledge of which intervention a main outcome (or class of outcomes). Attrition bias. information relating to whether the intended blinding was effective. assessors. Incomplete outcome Describe the completeness of outcome Attrition bias due to amount, data Assessments should be made for each main outcome (or class of outcomes).? data for each main outcome, including nature or handling of attrition and exclusions from the analysis. State whether attrition and exclusions were reported, the numbers in each intervention group (compared with total randomized participants), reasons for attrition/exclusions where reported, and any re-inclusions in analyses performed by the review authors. Reporting bias. incomplete outcome data. Reporting bias due to Selective reporting. State how the possibility of selective review authors, and what was found. Other bias. Other sources of bias. outcome reporting was examined by the selective outcome reporting. not addressed in the other domains in the tool. If particular questions/entries were pre-specified in the review’s protocol, responses should be provided for each question/entry. covered elsewhere in the table. State any important concerns about bias Bias due to problems not RANDOM SEQUENCE GENERATION Selection bias (biased allocation to interventions) due to inadequate generation of a randomised sequence. Criteria for a judgement The investigators describe a random component in the sequence of ‘Low risk’ of bias. generation process such as: • • • • • • 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 element, and this is considered to be equivalent to being random. Criteria for the of bias. The investigators describe a non-random component in the sequence 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 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 laboratory test or a series of tests; • Criteria for the risk’ of bias. Allocation by availability of the intervention. judgement of ‘High risk’ generation process. Usually, the description would involve some Insufficient information about the sequence generation process to judgement of ?‘Unclear permit judgement of ‘Low risk’ or ‘High risk’. ALLOCATION CONCEALMENT Selection bias (biased allocation to interventions) due to inadequate concealment of allocations prior to assignment. Criteria for a judgement Participants and investigators enrolling participants could not foresee of ‘Low risk’ of bias. assignment because one of the following, or an equivalent method, was used to conceal allocation: • Central allocation (including telephone, web-based and pharmacy-controlled randomization); • Sequentially numbered drug containers of identical appearance; • Criteria for the of bias. Sequentially numbered, opaque, sealed envelopes. Participants or investigators enrolling participants could possibly allocation based on: judgement of ‘High risk’ foresee assignments and thus introduce selection bias, such as • Using an open random allocation schedule (e.g. a list of random numbers); • Assignment envelopes were used without appropriate safeguards (e.g. if envelopes were unsealed or nonopaque or not sequentially numbered); • • • • Criteria for the risk’ of bias. Alternation or rotation; Date of birth; Case record number; Any other explicitly unconcealed procedure. Insufficient information to permit judgement of ‘Low risk’ or ‘High risk’. or not described in sufficient detail to allow a definite judgement – for example if the use of assignment envelopes is described, but it remains unclear whether envelopes were sequentially numbered, opaque and sealed. judgement of ?‘Unclear This is usually the case if the method of concealment is not described BLINDING OF PARTICIPANTS AND PERSONNEL Performance bias due to knowledge of the allocated interventions by participants and personnel during the study. Criteria for a judgement Any one of the following: of ‘Low risk’ of bias. • No blinding or incomplete blinding, but the review authors judge that the outcome is not likely to be influenced by lack of blinding; • Blinding of participants and key study personnel ensured, and unlikely that the blinding could have been broken. Criteria for the of bias. Any one of the following: • No blinding or incomplete blinding, and the outcome is likely to be influenced by lack of blinding; • Blinding of key study participants and personnel attempted, but likely that the blinding could have been broken, and the outcome is likely to be influenced by lack of blinding. Criteria for the judgement of ?‘Unclear risk’ of bias. Any one of the following: • Insufficient information to permit judgement of ‘Low risk’ or ‘High risk’; • The study did not address this outcome. judgement of ‘High risk’ BLINDING OF OUTCOME ASSESSMENT Detection bias due to knowledge of the allocated interventions by outcome assessors. Criteria for a judgement Any one of the following: of ‘Low risk’ of bias. • No blinding of outcome assessment, but the review authors judge that the outcome measurement is not likely to be influenced by lack of blinding; • Blinding of outcome assessment ensured, and unlikely that the blinding could have been broken. Criteria for the of bias. • Any one of the following: • No blinding of outcome assessment, and the outcome measurement is likely to be influenced by lack of blinding; Blinding of outcome assessment, but likely that the blinding could have been broken, and the outcome measurement is likely to be influenced by lack of blinding. Criteria for the judgement of ?‘Unclear risk’ of bias. • Any one of the following: • Insufficient information to permit judgement of ‘Low risk’ or ‘High risk’; The study did not address this outcome. judgement of ‘High risk’ INCOMPLETE OUTCOME DATA Attrition bias due to amount, nature or handling of incomplete outcome data. Criteria for a judgement Any one of the following: of ‘Low risk’ of bias. • • No missing outcome data; Reasons for missing outcome data unlikely to be related to true outcome (for survival data, censoring unlikely to be introducing bias); • Missing outcome data balanced in numbers across intervention groups, with similar reasons for missing data across groups; • For dichotomous outcome data, the proportion of missing outcomes compared with observed event risk not enough to have a clinically relevant impact on the intervention effect estimate; • For continuous outcome data, plausible effect size (difference in means or standardized difference in means) among missing outcomes not enough to have a clinically relevant impact on observed effect size; • Criteria for the Missing data have been imputed using appropriate methods. Any one of the following: • Reason for missing outcome data likely to be related to true judgement of ‘High risk’ of bias. outcome, with either imbalance in numbers or reasons for missing data across intervention groups; • 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) 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 the judgement of ?‘Unclear risk’ of bias. Any one of the following: • Insufficient reporting of attrition/exclusions to permit judgement of ‘Low risk’ or ‘High risk’ (e.g. number randomized not stated, no reasons for missing data provided); • The study did not address this outcome. SELECTIVE REPORTING Reporting bias due to selective outcome reporting. Criteria for a judgement Any of the following: of ‘Low risk’ of bias. • The study protocol is available and all of the study’s pre-specified (primary and secondary) outcomes that are of interest in the review have been reported in the pre-specified way; • The study protocol is not available but it is clear that the published reports include all expected outcomes, including those that were pre-specified (convincing text of this nature may be uncommon). Criteria for the of bias. • Any one of the following: • Not all of the study’s pre-specified primary outcomes have been reported; One or more primary outcomes is reported using measurements, analysis methods or subsets 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 judgement of ‘High risk’ incompletely so that 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 the risk’ of bias. Insufficient information to permit judgement of ‘Low risk’ or ‘High risk’. judgement of ?‘Unclear It is likely that the majority of studies will fall into this category. OTHER BIAS Bias due to problems not covered elsewhere in the table. Criteria for a judgement The study appears to be free of other sources of bias. of ‘Low risk’ of bias. Criteria for the of bias. There is at least one important risk of bias. For example, the study: • Had a potential source of bias related to the specific study design used; or • • Criteria for the judgement of ?‘Unclear risk’ of bias. • Has been claimed to have been fraudulent; or Had some other problem. judgement of ‘High risk’ There may be a risk of bias, but there is either: • Insufficient information to assess whether an important risk of bias exists; or Insufficient rationale or evidence that an identified problem will introduce bias. Table summary assessments of the risk of bias for each important outcome (across domains) within and across studies
Risk of bias Low risk of bias. Interpretation Within a study Across studies Plausible bias unlikely Low risk of bias for all Most information is from to seriously alter the results. key domains. studies at low risk of bias. Unclear risk of bias for Most information is from one or more key domains. High risk of bias for one or more key domains. studies at low or unclear risk of bias. The proportion of information from studies at high risk of bias is sufficient to affect the interpretation of results. Unclear risk of bias. Plausible bias that raises some doubt about the results. High risk of bias. Plausible bias that seriously weakens confidence in the results.
因篇幅问题不能全部显示，请点此查看更多更全内容