2016+SIGN国家临床指南：急性冠脉综合征（148）.pdf

SIGN 148 • Acute coronary syndrome A national clinical guideline April 2016 Evidence guide.medlive.cn KEY TO EVIDENCE STATEMENTS AND RECOMMENDATIONS LEVELS OF EVIDENCE 1 ++ High-quality meta-analyses, systematic reviews of RCTs, or RCTs with a very low risk of bias 1 + Well-conducted meta-analyses, systematic reviews, or RCTs with a low risk of bias 1 - Meta-analyses, systematic reviews, or RCTs with a high risk of bias 2 ++ High-quality systematic reviews of case-control or cohort studies High-quality case-control or cohort studies with a very low risk of confounding or bias and a high probability that the relationship is causal 2 + Well-conducted case-control or cohort studies with a low risk of confounding or bias and a moderate probability that the relationship is causal 2 - Case-control or cohort studies with a high risk of confounding or bias and a significant risk that the relationship is not causal 3 Non-analytic studies, eg case reports, case series 4 Expert opinion RECOMMENDATIONS Some recommendations can be made with more certainty than others. The wording used in the recommendations in this guideline denotes the certainty with which the recommendation is made (the ‘strength’ of the recommendation). The ‘strength’ of a recommendation takes into account the quality (level) of the evidence. Although higher-quality evidence is more likely to be associated with strong recommendations than lower-quality evidence, a particular level of quality does not automatically lead to a particular strength of recommendation. Other factors that are taken into account when forming recommendations include: relevance to the NHS in Scotland; applicability of published evidence to the target population; consistency of the body of evidence, and the balance of benefits and harms of the options. R For ‘strong’ recommendations on interventions that ‘should’ be used, the guideline development group is confident that, for the vast