Limitations
cancer
CANCER, ADVANCED CANCER
First, our finding that decisional uncertainty might be an adverse outcome of SDM should be interpreted with some caution, as in the current study we could not take into account the level of uncertainty that patients experienced at baseline. It might also be the case that uncertain or doubting patients would induce SDM behavior in oncologists. For example, if patients seem uncertain or hesitant about a treatment decision, oncologists may explain treatment options more elaborately or engage in preference construction. Second, despite the baseline controls performed for the other adverse outcomes, causality can also not be claimed for the other relationships found, due to the cross-sectional design of this study. The fact that a randomly assigned and highly effective oncologist training in SDM did not significantly relate to adverse outcomes might further substantiate that the reported relation between observed SDM and adverse outcomes is not necessarily, or purely, causal. Third, the follow-up measurement took place not directly but 1 wk after the consultation, possible influencing the outcomes. Lastly, it is important to bear in mind that our results apply only to the specific setting of patients with advanced cancer, defined as having a median life expectancy <12 mo and an expected median survival benefit of <6 mo due to treatment. Further research should determine how these results would translate into other cancer settings.