Heuristics are cognitive short-cutting strategies especially adaptive under the time and resource limitations but which occasionally fail

From Achieving quality in clinical decision making: cognitive strategies and detection of bias by Pat Croskerry.  From the Abstract: 

Clinical decision making is a cornerstone of high-quality care in emergency medicine. The density of decision making is unusually high in this unique milieu, and a combination of strategies has necessarily evolved to manage the load. In addition to the traditional hypothetico-deductive method, emergency physicians use several other approaches, principal among which are heuristics. These cognitive short-cutting strategies are especially adaptive under the time and resource limitations that prevail in many emergency departments (EDs), but occasionally they fail. When they do, we refer to them as cognitive errors. They are costly but highly preventable. It is important that emergency physicians be aware of the nature and extent of these heuristics and biases, or cognitive dispositions to respond (CDRs). Thirty are catalogued in this article, together with descriptions of their properties as well as the impact they have on clinical decision making in the ED. Strategies are delineated in each case, to minimize their occurrence. Detection and recognition of these cognitive phenomena are a first step in achieving cognitive de-biasing to improve clinical decision making in the ED.

An alternate source with access to the report is here.  

The thirty cognitive errors are:

Aggregate bias

Anchoring

Ascertainment bias

Availability and nonavailability

Base-rate neglect

Commission bias

Confirmation bias

Diagnosis momentum

Fundamental attribution error

Gambler’s fallacy

Gender bias

Hindsight bias

Multiple alternatives bias

Omission bias

Order effects

Outcome bias

Overconfidence bias

Playing the odds

Posterior probability error

Premature closure

Psych-out error

Representativeness

restraint

Search satisfying

Sutton’s slip

Triage-cueing

Unpacking principle

Vertical line failure

Visceral bias

Yin–yang out

Zebra retreat

Each bias is defined, and described with consequences identified and mitigations recommended.

Aggregate bias is defined and noted as synonymous with Ecological Fallacy.  The definition/discussion is:

The aggregate fallacy is when associations between variables representing group averages are mistakenly taken to reflect what is true for a particular individual, usually when individual measures are not available. Physicians may use the aggregate bias to rationalize treat- ing an individual patient differently from what has been agreed upon through clinical practice guidelines for a group of patients (i.e., there is a tendency for some physicians to treat their own patients as atypical). However, the aggregate fallacy argument does not apply because clinical practice guidelines have been established on individual data. Further, the clinician’s behavior may be augmented by a patient’s demanding behavior. Thus, a particular patient judged to have a viral upper respiratory tract infection may be treated with an antibiotic for perverse (irrational) reasons, or a patient with an ankle sprain who doesn’t satisfy the Ottawa Ankle Rules may be x-rayed. The aggregate bias may be compounded by those with a commission bias, who have a tendency to want to be seen as ‘‘doing something’’ for the patient.

Well worth reading in whole for a discussion of real world consequences to misapplied heuristics, biases, and cognitive dispositions to respond.