Previous research has highlighted the importance of physicians’ early hypotheses for their final diagnostic decisions. It has also been shown that diagnostic accuracy improves when physicians are presented with a list of diagnostic suggestions to consider at the start of the patient encounter. The psychological mechanisms underlying this improvement in accuracy have not yet been explored. It is possible that the provision of diagnostic suggestions, early in the clinical consultation, disrupts physicians’ intuitive thinking and reduces their initial diagnostic confidence. This possibly encourages physicians to seek more patient information before reaching a conclusion, evaluate this information in a more balanced fashion and be more inclined to change diagnosis when encountering new information.
Three online studies explored the effects of early diagnostic suggestions, provided by a hypothetical decision aid, on different aspects of the diagnostic process. General Practitioners (GPs) assessed up to two patient scenarios with and without the decision aid. We measured associations with certainty in the initial diagnostic hypothesis (initial confidence), information search and evaluation, and frequency of diagnostic changes. We detected mainly trends that were not statistically significant but were in the expected direction. We did measure a statistically significant impact of the decision aid on initial confidence (Study 1) and diagnostic changes (Study 3). We also measured significant associations between participants’ Actively Open-Minded Thinking (Baron, 2019) and GPs’ initial confidence and information search: GPs with higher scores in Actively Open-minded Thinking (AOT) scale had lower confidence in their initial diagnosis (Studies 1 and 3) and engaged in a more extensive search of information before providing their conclusion (Studies 2 and 3).
In all three studies, initial confidence was found to have significant downstream effects: it was associated with less extensive information search, more biased evaluation of neutral information, fewer diagnostic changes when new information was encountered, and a shorter list of differential diagnoses recorded. A systematic review on initial confidence and resistance to change was subsequently conducted to assess the evidence for this phenomenon and found that initial confidence can determine whether, and to what extent, an initial judgement tends to change over time.
In conclusion, this thesis found that early diagnostic suggestions may impact physicians’ confidence, information search and evaluation, but the most prominent effects on behaviour are determined by the physician’s confidence in their initial diagnostic hypothesis.