Using Item Response Theory (IRT) to Reduce Patient Burden When Assessing Desire for Hastened Death

Desire for hastened death (DHD) represents a wish to die sooner than might occur by natural disease progression. Efficient and accurate assessment of DHD is vital for clinicians providing care to terminally ill patients. The Schedule of Attitudes Toward Hastened Death (SAHD) is a commonly used self-report measure of DHD. The goal of this study was to use methods grounded in item response theory (IRT) to analyze the psychometric properties of the SAHD and identify an abbreviated version of the scale. Data were drawn from 4 studies of psychological distress at the end of life. Participants were 1,076 patients diagnosed with either advanced cancer or AIDS. The sample was divided into 2 subsamples for scale analysis and development of the shortened form. IRT was used to estimate item parameters. A 6-item version of the SAHD (SAHD-A) was identified through examination of item parameter estimations. The SAHD-A demonstrated adequate convergent validity. Receiver operating characteristic analyses indicated comparable cut scores to identify patients with high levels of DHD. These analyses support the utility of the SAHD-A, which can be more easily integrated into research studies and clinical assessments of DHD.