AVAILABILITY BIAS:
A bias that occurs when ones uses immediate examples or information in ones memory to make judgements, evaluate a concept, or make a decision1,2. Or in other words, when one weights the most recent (i.e. newest) information in their memory as being the most important for decision making.
Availability Bias may affect patients when they are required to recall information on prior exposures they may have encountered, when meeting with a physician; recalling the most recent exposure as being the most important for their disease, when in fact it may not be. Availability Bias may also affect physician diagnoses; such that they may be influenced by a recent experience with a certain kind of disease, and thus be more likely to diagnose other similar diseases as that type of disease, when they may not be2. Availability Bias is thus a specific type of Recall Bias.
In some cases the term Availability Bias is used informally to refer to any biases that occur due to missing information in one group vs. another3. Use of the term in this context is not useful as it does not specify the mechanism of the missing information, and thus could refer to any range of possible Information Biases. Also see: Recall Bias, Underlying Cause Bias (Rumination Bias), Family Information Bias, Exposure Suspicion Bias, Diagnostic Suspicion Bias, Clinical Review Bias, and Information Bias.
References:
1. Ihara S, Shikino K, Ikusaka M. A case of availability bias for COVID-19 causing scrub typhus diagnostic errors. Journal of general and family medicine. 2022;23(1):52-3. (Link to Reference)
2. Li P, Cheng ZY, Liu GL. Availability Bias Causes Misdiagnoses by Physicians: Direct Evidence from a Randomized Controlled Trial. Internal medicine (Tokyo, Japan). 2020;59(24):3141-6. (Link to Reference)
3. Tsujimoto Y, Fujii T, Onishi A, Omae K, Luo Y, Imai H, et al. No consistent evidence of data availability bias existed in recent individual participant data meta-analyses: a meta-epidemiological study. J Clin Epidemiol. 2020;118:107-14.e5. (Link to Reference)