Interviews

Interviews were performed using a form of Cognitive Task Analysis termed the Critical Decision Method (CDM).¹⁸ CDM is a retrospective interview strategy designed to clarify the cognitive processes of specific incidences that require expert judgment. Experts are known to have difficulty accessing their knowledge (due to the degree of overlearning). This qualitative method uses cognitive probes aimed at identifying both explicit and implicit knowledge involved in specific decisions and behaviors for critical incidents. The technique is designed to maximize recall by using 3 waves of review that explore the context of the case, the goals, decision points, information needs, behavioral options, and strategies. Further details are listed in the Supplement.

The overall goal was to explore decision-making, planning and sense-making for a specific incident. CDM is a more effective technique for extracting complex information than what could be obtained in a generalized interview about typical procedures because it elicits both tacit and explicit knowledge.¹⁹ CDM was chosen as it is best for rare events such as ECPR and accommodates heterogenous groups.²⁰

All interviews were done individually, audio recorded, and transcribed. Prior to the interview, participants were asked to identify and review a specific memorable clinical case in which ECPR was used, or one in which it was strongly considered, but not used. At the interview, investigators used a previously developed script that was piloted and tested for clarity with three ICU fellows who had participated in ECPR.

The interviews, as described, were designed to identify and extract explicit and implicit knowledge and decision making around the use of ECPR, in order to inform the feasibility of a RCT among physicians who already routinely perform ECPR. The analysis of the interviews, described below, enabled us to then identify high level themes present across respondents. As such, individual cases and decision making difficulties are not presented beyond the direct quotes (Tables).