Abstract: Objective To develop a suicide risk assessment scale for cancer patients and to provide reference for suicide risk assessment and effective targeted intervention program for cancer patients. Methods Based on the Three-Step Theory of Suicide, with reference to the Beck Hopelessness Scale, Interpersonal Needs Questionnaire, and entry settings of Suicidal Ability Scale, the initial scale was constructed after literature review, semi-structured interview, group discussion, and Delphi method. Convenience sampling was used to select 140 patients in a tertiary grade-A hospital in Shanghai for the first investigation, and the final version of the scale was formed through item analysis and exploratory factor analysis. Convenience sampling was used to select 205 patients in a tertiary grade-A hospital in Shanghai for the second investigation, and the scale performance was further examined through confirmatory factor analysis and reliability analysis. Results The suicide risk assessment scale for cancer patients consisted of 3 dimensions of distress, feelings of hopelessness and association, suicidal ability and 15 items. The model fit of the scale was good. The Cronbach's alpha coefficient of internal consistency of the total table was 0.907; half-fold reliability 0.818; and content validity index of the total table 0.920. With the Suicidal Behaviors Questionnaire-Revised (SBQ-R) as the gold standard and a cutoff value of 30 points for the equivalence scale, the sensitivity and specificity were 63.60% and 78.10%, respectively, with an area under the ROC curve of 0.766. Conclusion The scale has good reliability and validity, and it can be used as a suicide risk assessment tool for patients with cancer.

Key words: cancer, suicide, Three-Step Theory of Suicide, reliability, validity