We obtained approval to conduct the study from the Ethics Committee of Sapporo Medical University. Further,
the study was carried out after obtaining informed consent to participate by explaining the outline of the study to
the director of the participating health care centers orally and through a letter to request participation in the study.
The outline of the study was also explained to the participating PHNs orally and through a letter to request participation
in the study, and written consent was obtained prior to the interview. Participants were assured that
confidentiality would be maintained at all times, that research findings would not be used for purposes other
than the study, and the cases would be sensitively handled and that the anonymity of both PHNs and others involved
in the cases would be ensured.