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Dealing with treatment uncertainty in elderly AML patients
are ambiguity neutral, and 50 are ambiguity seeking. Regarding the Allais paradox, the AC, BD, AD and BC choice patterns were found in 90 (42.9%), 11 (5.2%), 102 (48.6%), and 7 (3.3%) assessable subjects, respectively, which represents 101 EU respondents (48.1%) and 109 non-EU respondents (51.9%). Mean self-reported willing- ness to take risks is 4.1 (SD±2.4) in the financial domain, 5.1 (SD±2.1) in their personal life, 5.3 (SD±2.1) for a patient’s health, and 5.7 (SD±2.1) for their own health.
K-means clustering identifies two populations of physicians
From the pattern of responses to the 6 clinical vignettes, the K-means clustering (see Online Supplementary Appendix Section III for details) allowed us to separate two groups of physicians: one group of clinicians with lower MDM- scores, i.e. more likely to choose intensive therapy (IC group), and another group of clinicians with higher MDM-scores, i.e. more likely to choose non-intensive therapy (Non-IC group).
IC-physicians harbor specific behavioral characteris- tics compared with non-IC-physicians
A bivariate comparison of the characteristics of physi- cians in the IC and Non-IC groups is summarized in Table 2. We detected significantly more aversion toward uncer- tainty within the IC cluster (mean certainty equivalents of 228 euros for the Non-IC group vs. 276 euros for the IC group; P=0.031) (Table 2). For the Allais paradox, we detected a trend toward significance (P=0.086) with more EU subjects in the Non-IC group (57%) than in the IC group (44%). Among the demographical and occupational characteristics, only the patient volume was associated with these clusters, with a mean number of older AML patients treated annually of 19.1 in the IC group versus 24.5 in the non-IC group (P=0.03). Although we found more male and risk-averse physicians in the IC group, these differences were not significant (P=0.06 and P=0.131, respectively).
The logistical regression of the IC versus non-IC groups, on individual characteristics that were significant with a P-value <0.20 in the bivariate analysis, is presented in Table 3. This analysis confirmed that aversion towards uncertainty increases the probability of belonging to the IC group [OR (95%CI): 1.17 (1.01;1.37); P=0.043] and that
higher patient volume increases the probability of being in the non-IC group [OR (95%CI): 0.98 (0.96;0.99); P=0.032]. We found an interaction between gender and the Allais paradox resulting in a statistically significant increase in the probability of being pro-IC among men who do not conform to the Expected Utility model [OR (95%CI): 3.45 (1.34;8.85); P=0.01], but such an effect was not found among women.
Discussion
In this cross-sectional national survey, we evaluated the impact of physicians’ behavioral characteristics on their medical decision-making in older patients with AML. We hypothesized that physicians’ behavioral traits such as risk and uncertainty aversion or rationality could be corre- lated with their choice between intensive and less-inten- sive therapy. To our knowledge, this is the first evidence that physicians belonging to the uncertainty-tolerant group recommend IC significantly less often than uncer- tainty-averse physicians, and that male physicians consid- ered as “economically irrational” prescribe more IC.
Several non-biological factors (NBF) are known to be associated with a patient’s health-related outcomes such as socio-economic status (SES), area of residence or mari- tal status.29,30 In the spectrum of NBFs affecting cancer patient outcomes, physician’s characteristics have been described as therapy determinants in the setting of allo- geneic stem cell transplantation for hematologic malignan- cies12 and solid tumors.31 In our study, neither age, hierar- chical status or years of experience influenced the tenden- cy of physicians to belong to the IC or Non-IC group, while individual uncertainty aversion was a strong deter- minant of practice variations in multivariate analysis. Volume-outcome relationships at treatment facility level32,33 and at physician level34 are well described with NBF affecting the outcome of patients with cancer. It is worthy of note that our study gets behind the volume- outcome relationship in AML, while connecting physi- cian’s patient volume with medical decision-making and more precisely with therapy intensity.
Verma et al.35 stated that physicians should learn about the individual behavioral mechanisms underpinning choices under uncertainty. Our findings go one step fur-
Figure 2. Medical decision-making among the 6 clinical vignettes. Proportion of physicians choos- ing intensive chemotherapy, low-intensity therapy or best supportive care for each of the 6 clinical vignettes.
haematologica | 2018; 103(12)
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