Surrogate endpoints: pitfalls of easier questions

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• Format Texts
• Language/s English
• Target Audience Further education
• EBM Stage 1 - Asking focused questions, 3 - Appraising evidence, 4 - Decision making
• Duration <5 mins
• Difficulty Introductory

Key Concepts addressed

• 3-2a Do the outcomes measured matter to you?

Details

This blog explains what ‘surrogate endpoints’ are, as opposed to ‘direct endpoints’.

The blog then highlights the problems with focusing on surrogate endpoints. For instance, treatments may improve surrogate endpoints but may fail to positively affect ‘direct’ endpoints (i.e. outcomes of relevance to patients). Treatments may also have unfavourable effects, despite having a ‘beneficial’ effect on surrogate endpoints. For instance, hormone replacement treatment may raise a woman’s HDL level (basically, one’s concentration of ‘good’ cholesterol) but this treatment may also increase the risk of deep vein thrombosis and breast cancer.

Given the problems associated with surrogate endpoints, the blog author suggests focusing on POEMS (patient-oriented evidence that matters). This is direct evidence that a medical intervention, on average, lengthens life, decreases symptoms, and improves life quality. However, when such evidence is not available, the blog author describes a hierarchical approach to selecting the best evidence available. Read the blog

Students 4 Best Evidence (S4BE) is a growing network of students from around the world, from school age to university, who are interested in learning more about evidence-based healthcare (EBH).  The network is supported by the UK Cochrane Centre.  In addition to the website, the S4BE has a Facebook group and Twitter feed. For more information, read Selena Ryan-Vigs blog which introduces Students 4 Best Evidence.