Objective: To determine the usefulness of Q methodology to locate and describe shared subjective influences on clinical decision making among participant physicians using hypothetical cases containing common ethical issues. Design: Qualitative study using by-person factor analysis of subjective Q sort data matrix. Setting: University medical center. Participants: Convenience sample of internal medicine attending physicians and house staff (n = 35) at one midwestern academic health sciences center. Interventions: Presented with four hypothetical cases involving urgent decision making near the end of (...) life, participants selected one of three specific clinical actions offered for each case. Immediately afterward and while considering their decision, each respondent sorted twenty-five subjective self-referent items in terms of the influence of each statement on their decision-making process. By-person factor analysis, where participants are defined as variates, yielded information about the attitudinal background the physicians brought to their consideration of each hypothetical case. We performed a second-order factor analysis on all of the subjective viewpoints to determine if a smaller core of shared attitudes existed across some or all of the four case vignettes. Factor scores for each item and post-sort comments from interviews conducted individually with each respondent guided the interpretation of ethical perspective used by these respondents in making clinical decisions about the cases. Measurements and Main Results: Second-order factor analysis on seventeen viewpoints used by physicians in the four hypothetical urgent decision cases revealed three moderately correlated (r 2 < 40%) subjective core attitudinal guides used broadly among all the cases and among sixteen of the seventeen original factors. Across all the cases, our participants were guided in general by: (1) patient-focused beneficence, (2) a patient- and surrogate-focused perspective that includes risk avoidance, and (3) best interest of the patient guided by ethical values. Economic impact on the physician, expediency in resolution of the situation, and the expense of medical treatment were not found to be influential determinants in this study. Conclusions: Q sorting and by-person factor analysis are useful qualitative methodological tools to study the complex structure of subjective attitudes that influence physicians in making medical decisions. This study revealed the subjective viewpoints used by our physician participants as they made ethically challenging treatment decisions. The three second-order factors identified here are grounded in current bioethical values as well as the personal traits of physicians. The participants' decision methods appear to resemble casuistry more than principle-based decision making. Generalizability of results will require further studies. (shrink)