Surrogate outcomes are often used as proxies for hard clinical outcomes, as they enable smaller, faster, and thus cheaper clinical trials. In addition, pharmaceutical companies argue that using surrogates means that fewer patients are exposed during testing, and beneficial new medications reach the market faster. Their main disadvantage is that favorable effects on surrogates do not automatically translate into benefits to health.
To illustrate the perils of relying on surrogates, we compiled a table of drugs, approved on the basis of surrogate outcome data, which after adoption into practice were shown to be harmful through clinical trials or meta-analyses (eTable).
Svensson S, Menkes DB, Lexchin J. Surrogate Outcomes in Clinical TrialsA Cautionary Tale. JAMA Intern Med. 2013;173(8):611–612. doi:10.1001/jamainternmed.2013.3037