诊断类Meta分析的GRADE评级实例教学

Factors that determine and can decrease quality of evidence

Explanations and differences from quality of evidence for other interventions

Study design
研究设计

Different criteria for accuracy studies—Cross sectional or cohort studies in patients with diagnostic uncertainty and direct comparison of test results with an appropriate reference standard are considered high quality and can move to moderate, low, or very low depending on other factors.
准确性研究的不同标准-在诊断不确定的患者中进行的横断面或队列研究以及将检测结果与适当的参考标准进行直接比较被认为是高质量的，并且可以根据其他因素移至中等、低或非常低

Limitations (risk of bias)
局限性（偏倚风险）

Different criteria for accuracy studies—Consecutive patients should be recruited as a single cohort and not classified by disease state, and selection as well as referral process should be clearly described. Tests should be done in all patients in the same patient population for new test and well described reference standard; evaluators should be blind to results of alternative test and reference standard.
准确性研究的不同标准-连续性患者应作为一个队列招募，而不是根据疾病状态分类，并应明确描述选择和转诊过程。对于新的检测方法和描述良好的参比标准品，应在同一患者人群的所有患者中进行检测;评价者应对替代检测方法和参比标准品的结果设盲

Indirectness:
间接性：

Outcomes

Similar criteria—Panels assessing diagnostic tests often face an absence of direct evidence about impact on patient-important outcomes. They must make deductions from studies of diagnostic tests about the balance between the presumed influences on patient-important outcomes of any differences in true and false positives and true and false negatives in relation to complications and costs of the test. Therefore, accuracy studies typically provide low quality evidence for making recommendations owing to indirectness of the outcomes, similar to surrogate outcomes for treatments.
类似的标准-评估诊断测试的小组经常面临缺乏直接证据的影响，对病人的重要结果。他们必须从诊断测试的研究中推断出，在真阳性和假阳性以及真阴性和假阴性的任何差异对患者重要结果的假定影响与测试的并发症和成本之间的平衡。因此，由于结果的间接性，准确性研究通常为提出建议提供低质量的证据，类似于治疗的替代结果

Patient populations, diagnostic test, comparison test, and indirect comparisons
患者人群、诊断试验、比较试验和间接比较

Similar criteria—Quality of evidence can be reduced if important differences exist between populations studied and those for whom recommendation is intended (in previous testing, spectrum of disease or comorbidity); if important differences exist in tests studied and diagnostic expertise of people applying them in studies compared with settings for which recommendations are intended; or if tests being compared are each compared with a reference (gold) standard in different studies and not directly compared in same studies.
类似的标准-如果研究人群和推荐人群之间存在重要差异，则证据质量可能会降低（在先前的测试中，疾病谱或合并症）;如果研究的测试和研究中应用它们的人的诊断专业知识与建议预期的设置相比存在重要差异;或者如果在不同的研究中将每个被比较的测试与参考（金）标准进行比较，而不是在相同的研究中直接比较

Important inconsistency in study results
研究结果的重要不一致性

Similar criteria—For accuracy studies, unexplained inconsistency in sensitivity, specificity, or likelihood ratios (rather than relative risk or mean differences) can reduce quality of evidence.
类似标准-对于准确性研究，灵敏度、特异性或似然比（而不是相对风险或平均差异）中无法解释的不一致可能会降低证据质量

Imprecise evidence
不确切的证据

Similar criteria—For accuracy studies, wide confidence intervals for estimates of test accuracy or true and false positive and negative rates can reduce quality of evidence.
相似的标准--对于准确性研究，测试准确性或真、假阳性率和阴性率的估计值的置信区间过宽会降低证据的质量

High probability of publication bias
发表偏倚概率高

Similar criteria—High risk of publication bias (for example, evidence from small studies for new intervention or test, or asymmetry in funnel plot) can lower quality of evidence.
类似标准-发表偏倚的高风险（例如，来自新干预或测试的小型研究的证据，或漏斗图中的不对称性）可能会降低证据质量