Decision-making in Orthopaedic Oncology: Does Cognitive Bias Affect a Virtual Patient’s Choice Between Limb Salvage and Amputation?
Authors: Gurich Richard W. , Cizik Amy M. , Punt Stephanie E. , Namekata Michael , Johnson Christopher N. , Symons Rebecca G. , Brewer Elena G. , Thompson Matthew J. 
Published: May 2019

Abstract

Background
The local treatment of extremity sarcomas usually is predicated on a decision between limb salvage and amputation. The manner in which surgical options are presented in the context of shared decision-making may influence this decision. In a population of “simulated” patients–survey respondents presented with a mock clinical vignette and then asked to choose between treatments–we assessed cognitive bias by deliberate alteration of the subjective presentation of the same objective information.

Questions/purposes
(1) Will the manner in which information is presented to a simulated patient, in the setting of treatment for a bone sarcoma, bias their decision regarding pursuing amputation versus limb salvage? (2) At the time of decision-making, will a simulated patient’s personal background, demographics, or mood affect their ultimate decision?

Methods
Survey respondents (Amazon MTurk platform) were presented with mock clinical vignettes simulating a sarcoma diagnosis and were asked to choose between amputation and limb salvage. Specific iterations were designed to assess several described types of cognitive bias. These scenarios were distributed, using anonymous online surveys, to potential participants aged 18 years or older. Recruitment was geographically restricted to individuals in the United States. Overall, 404 respondents completed the survey. The average age of respondents was 33 years (SD 1.2 years), 60% were male and 40% were female. In all, 12% of respondents worked in healthcare. Each respondent also completed questions regarding his or her demographics and his or her current mood. Associations between the type of bias presented and the respondent’s choice of limb salvage versus amputation were examined. Independent sample t-tests were used to compare means. Statistical significance was defined as p < 0.05.

Results
When amputation was presented as an option to mitigate functional loss (framing bias), more patients chose it than when limb salvage was presented as means for increased functional gains (23% [23 of 100] versus 10% [12 of 118], odds ratio [OR], 2.26; p = 0.010). Older simulated patients were more likely to choose limb salvage when exposed to framing bias versus younger patients (mean age 33 years versus 30 years, p = 0.02). Respondents who were employed in healthcare more commonly chose amputation versus limb salvage when exposed to framing bias (24% [eight of 35] versus 9% [17 of 183]; OR, 2.46; p = 0.02). Those who chose amputation were more likely to score higher on scales that measured depression or negative affect.

Conclusions
Shared decision-making in orthopaedic oncology represents a unique circumstance in which several variables may influence a patient’s decision between limb salvage and amputation. Invoking cognitive bias in simulated patients appeared to affect treatment decisions. We cannot be sure that these findings translate to the experience of actual sarcoma patients; however, we can conclude that important treatment decisions may be affected by cognitive bias and that patient characteristics (in this study, age, healthcare profession, and mood) may be associated with an individual’s susceptibility to cognitive bias. We hope these observations will assist providers in the thoughtful delivery of highly charged information to patients facing difficult decisions, and promote further study of this important concept.

Level of Evidence
Level III, economic and decision analyses.