Objectives: In patients living with advanced dementia, the intensity of care during life-threatening infections remains controversial and marked by wide variation in practice. This international survey investigated physicians' and physicians-in-training's management choices for individuals with advanced dementia and the factors associated with those choices.

Design: Vignette-based survey.

Setting: Twelve countries across five continents.

Methods: We administered our vignette-based survey to medical students, residents and physicians. The survey elicited participants' views on whether antibiotics should be administered to an elderly patient with advanced dementia and very poor quality of life, presenting with bacterial pneumonia. We explored factors associated with treatment choices using univariable analysis and multiple logistic regression models.

Results: Of the 785 participants (age, mean (SD): 31.1 (11.5) years), one-third (31.2%) resided in the Region of the Americas, 21.9% in Europe, 16.2% in the Eastern Mediterranean region and 17.1% in China. In the univariable analysis, choice to treat was associated with younger age, country/WHO region (African region highest overall, European region lowest overall), stage of medical training (medical student most inclined to treat) and absence of medical assistance in dying (MAiD) legislation. Multivariable analyses provided evidence that country was the variable most strongly associated with the choice to treat with antibiotics (Cameroon, China, Saudi Arabia highest; Norway, Switzerland, Spain lowest), with the presence of MAiD legislation also strongly associated (OR 0.35, 95% CI 0.23 to 0.51). Age (OR 0.82, 95% CI 0.66 to 1.00) and religiosity level (OR 0.93, 95% CI 0.87 to 0.99) showed weaker associations with treatment decisions.

Conclusion: Inclination to treat individuals with advanced dementia who develop pneumonia varies greatly between and within jurisdictions. Social factors (in particular country but also presence of MAiD legislation) proved the most prominent associations, with individual characteristics much less influential. These findings underscore the importance of contextual and cultural factors in value-sensitive clinical decisions.

Registration: We registered the protocol at Open Science Framework (osf.io/6kfbt).