EVIDENCE OF COGNITIVE BIAS IN DECISION MAKING AROUND IMPLANTABLE-CARDIOVERTER DEFIBRILLATORS: A QUALITATIVE FRAMEWORK ANALYSIS

Purpose:  Prior studies have raised concerns about the quality of complex decision making for medical technologies. In the case of implantable cardioverter-defibrillators (ICDs), research suggests that physicians give more importance to guidelines than they do for patient perspectives and generally recommend therapy based simply on guidelines. Likewise, research suggests that patients often misunderstand the functionality of their ICD and overestimate the benefit. To improve upon medical decision making, we need a better understanding of the behavioral influences at play.

Methods:  We used the qualitative framework method of content analysis. The initial framework included 10 salient cognitive biases from the field of behavioral economics and decision psychology: affect heuristic, affective forecasting, anchoring, availability, default effects, dual-process, halo effects, optimism bias, framing effects, and state dependence. We then applied this framework to two sets of qualitative interviews with patients who had experienced ICD decision making (one from 2010 and one from 2013). Through an iterative process of coding and reviewing, we determined which cognitive biases appeared to be most influential in recollections of ICD decision making.

Results:   We interviewed 48 patients from 4 settings in the Denver area: 38 with ICDs and 10 who had declined ICDs. The majority were male (n=32). Median age was 59.6 years. Throughout the interviews, we found strong evidence of framing effects, default effects, and halo effects (see table). Framing effects were apparent in overestimation of benefits and downplaying or omitting potential harms. A strong default effect was seen performing the ICD implantation. The participants also seemed to infer a halo effect around both the clinician as well as the technology itself.

Conclusions:  We found evidence of cognitive bias in decision making for ICD implantation. Participants attribute a halo effect to a clinician, who then presents a default to perform an ICD (a therapy which also enjoys a halo) using influential framing techniques. Taken together, the biases generally encouraged ICD treatment. Assisting patients in making informed decisions in this context will require overcoming ingrained bias in current ICD decision making.