The present study serves as the first exploratory trial for a systematic evaluation of medical ethics education in Japan. This study's test battery for the PIT and the DIT, which measures the first two steps of the four-component model of problem identification and moral reasoning, could serve as an objective and brief method for assessing courses' varying designs, methods, and curriculums.
Concerning the significance of combining the PIT and DIT
As indicated in the Background, the combination of the two tests is conceptually valid since they are theoretically measuring different aspects of Rest's four-component model. Calculations of correlation coefficients between PIT and DIT scores found no items to be significantly correlated. Our finding of no significant correlation may lend additional support to the hypothesis that the DIT and PIT each measure different variables. Nonetheless, this lack of correlation is possibly related to the fact that the PIT was designed for medical settings while the DIT was originally created without such specificity. Further validation studies may be needed.
Concerning the results of the PIT
The PIT results described a significant increase in fourth and fifth year medical students for Domain B and a decrease among sixth year students and residents. This trend of decreasing values amongst graduates is consistent with research previously conducted [12, 15]. The decrease in moral sensitivity is likely to arise from residents being too busy to think about ethics and sixth year students being too busy preparing for the national exam. While these findings may be similar to previous studies, we propose that a positive interpretation may be possible. For example, as subjects accumulate clinical experience, they begin to sense and intuitively resolve ethical problems without identifying them as, per se, ethical dilemmas. That is, students begin to react to so-called ethical problems in an ethically correct manner without having to second-guess. An exemplary case is that of informed consent; residents may no longer consider it an ethical dilemma.
The increase in PIT scores among fourth and fifth year students suggests that the onset of bedside learning during one's fourth year has an effect on students' ethical awareness. Although students enroll in a medical ethics course at the end of their second year, we surmise that the course's teachings may be better understood once students begin to attend to patients. Further research is needed concerning possible factors to this increase in moral sensitivity among mid-year medical students.
Concerning the results of the DIT
Vignette 2 decision making exemplified a significant change in choice between school years. This change may reflect a more passive attitude regarding euthanasia as a result of students' and residents' practical experience with clinical medicine. Vignette 1 decision-making also showed a significant gradual change between school years (age groups). Overall, our results showed that moral development stage was consistent regardless of age group; these findings correlate with those of previous studies [16–19].
A significant difference in DP3 and DP4 values was recognized throughout school years. Kohlberg's theory, which contends that moral development increases with age, may be able to explain this divergence in DP3 and DP4 values among respondents. Kohlberg's work and thus the theories upon which the DIT is based have been widely criticized and discussed [20]. Kohlberg's equation of moral reasoning is largely based on justice reasoning. The works of Noddings and Gilligan indirectly draw attention to this distinction by emphasizing an ethics of care in contrast to an ethics of justice in accounting for morality [21, 22]. In short, while moral reasoning is applicable to the milieu of medical ethics, that of justice reasoning may not.
Several researchers have criticized Kohlberg's notions in that their justice-laden framework is inapt to the Japanese cultural background where interpersonal relationships are highly valued [8]. Accordingly, an environment where interpersonal relationships and consideration of peripheral circumstances are prioritized over reasons of justice weighs Kohlberg's 3rd and 4th stages of moral development with greater significance than the 5th and 6th stages.
In light of the above, we surmise that DIT results regarding decision-making carry more significance than those results pertaining to simple moral development stage and DP values. While the original DIT may be able to assess moral reasoning in the context of medical ethics to some degree, we contend that changes in subjects' moral thoughts (decision-making) can be evaluated by using the two most relevant vignettes.
Limitations of the present study
Interpretation of results is to some extent limited by the hypothetical character of the scenarios and by the sampling of students and residents affiliated with only one medical school located in an urban area of Japan. Additionally, the response rate for residents was low. This may be in association with respondents' level of interest regarding ethical issues. Further comparative studies are needed between residents in order to investigate this possible factor.
As recognized by Hebert and colleagues, the PIT survey may be incapable of evaluating other aspects of morality including attitudes, skills, facts and formal knowledge [13]. This test battery examines only the first two steps of the four component model. Further research to develop the other two components is necessary. Lastly, this study is limited by a quantitative approach [23, 24], and is cross-sectional and not longitudinal in design [19, 25].