INTRODUCTION:

Cognitive biases can be the source of up to 75% of medical errors [1]. We usually see clinicians making a diagnosis or taking clinical decisions based on their clinical expertise. A study demonstrated that 25% of emergency physicians elaborate on their diagnosis hypothesis before meeting the patient and 75% within the initial five minutes of consulting [2]. Kahneman and Tversky proposed a dual-system framework to explain human judgments and decisions [3]. The first path is an easier and quicker way to decide, and it is based on previous experiences. The second path is a more rational and deliberated way, based on critical thinking. Most of the cognitive biases that lead to medical mistakes are because of decisions made relying on the first path, which are clinical guesses that individuals make based on automated thought of previous associations [4]. Another common cause of medical mistakes is due to harmful omissions and commissions. Omissions in medicine are followed with questions such as “Am I right about my diagnosis? Should I wait for a second opinion?” and it can delay emergency situations, just like placing a chest tube in a pneumothorax. On the other hand, commissions usually come along with the following thinking: “better safe than sorry” [5]. With the awareness of the medical community rising on cognitive biases based on over 32 types described [6], we would like to propose a new one called “Schrödinger’s cat bias.” MATERIALS AND METHODS: A non-systematic review was conducted searching on the PubMed/MEDLINE database for articles published at any time discussing cognitive biases, particularly in clinical practice. Search terms included “cognitive biases” in the title, abstract, or publication type combined with “clinical practice” in the title or abstract.

These terms were further combined with one or more of the following terms in the title or abstract fields:

‘cognitive heuristics’ or “counterfactual thinking”. Resultant articles were cross-referenced for other pertinent articles not identified in the initial search about specific biases, such as commission bias, or were written by eminent scientists in this field. For the examples chosen to illustrate the bias, cases that match the author’s reality and routine as an interventional cardiologist were described and a direct search was performed for the relevant evidence about each case.

RESULTS:

The Schrödinger's cat cognitive bias In 1935, Erwin Schrödinger proposed an example of quantum mechanics applied in a more complex macroscopic system. The system includes a cat and a radioactive particle which can decay and drop poison that kills the cat. It creates a state of superposition in which the cat is dead and alive at the same time. If the particle has not decayed, the cat is alive; if it did, the cat is dead [7]. The bias proposed in this paper is that an individual, because he does not have the chance to live parallel timelines, does not have the capacity, as he has not got practical experience, to analyze what could have happened to him if he or his doctor had made a different decision. This is particularly relevant in medicine. Patients usually overestimate benefits and underestimate risks. If one comes out alive from an intervention, he may feel grateful for that because even if he evolved badly, at least he didn’t live the timeline in which no intervention was performed.