THE ROLE OF AMBIGUITY IN LUNG CANCER SCREENING DECISION MAKING

Purpose: The objective of this study was to elucidate the role of tolerance of ambiguity and response to stochastic, statistical, and evidentiary uncertainty in the valuation of benefits and harms in the context of lung cancer screening (LCS) decision making.

Method:  Structured interviews were conducted among a sample of current or former smokers, aged 40-75, recruited from primary care and pulmonary practices in Philadelphia.  An interview guide included prompts related to benefits, harms, response to general ambiguity and specific constructs of uncertainty (stochastic, statistical, and evidentiary) associated with LCS.  Graphics were used to convey relevant outcomes from the National Lung Screening Trial including elaborations to depict statistical uncertainty (Figure). Interviews were audio-recorded, transcribed, and independently coded by 2 investigators. An inductive approach was undertaken with themes and categories allowed to emerge from iterative review of the data.

Result:  The study population (n=22) was diverse in age, gender, and education with the majority of participants African American. Four salient themes emerged from the study: 1) variation was observed in tolerance for ambiguity in the context of LCS decision making, 2) tolerance for ambiguity impacts the way that people balance the various benefits and harms of LCS, 3) understanding of random, statistical and evidentiary uncertainty influenced attitudes towards LCS, and 4) provider communication was able to mitigate concerns about ambiguity. The desire to avoid or maintain ambiguity emerged as a motivating factor in decision making for lung cancer screening.  Some sought to avoid ambiguity through seeking additional information from screening, additional imaging, and second opinions; “I fear what I don't know because what I know I feel like I can control.”  In contrast, others sought to avoid ambiguity associated with false positive findings or overdiagnosis by declining LCS. Some were more tolerant of ambiguity, recognizing it as part of everyday life.  There was general understanding of the magnitude of expected outcomes conveyed in pictographs and statistical imprecision but random uncertainty remained a difficult concept to grasp.  Poor understanding of the natural history of cancer confounded the relationship between tolerance of ambiguity and LCS decisions. 

Conclusion:   A communication strategy that addresses the specific type of uncertainty concerning to patients and provides context and information pertaining to that concern will best support an effective shared decision making process.