Development of a short and an ultra-brief version of the Saving Inventory-revised (SI-R) for assessing hoarding severity: the SI-R9 and the SI-R3

Hoarding Disorder (HD) is marked by the inability to discard possessions, and often excessive acquiring, which results in cluttered living spaces that substantially disrupt daily life. While the Saving Inventory-Revised (SI-R) serves as a reliable and valid tool for assessing hoarding severity, its length may preclude routine use. We aimed to develop a valid shorter version of the scale using Item Response Theory and Confirmatory Factor Analysis in a non-selected sample of 2890 individuals and a clinical HD sample of 200 participants, which were divided into test and confirmatory samples in a 2:1 ratio. This led to a 9-item SI-R9, containing the original three subscales of discarding, clutter and acquiring; and an ultra-brief 3-item scale, the SI-R3. The original and revised versions demonstrated construct, convergent, and divergent validity. Significant gender differential was noted on some items, particularly those from the full SI-R, but was small in nature. Clinical cut-offs for all three scales showed good sensitivity and specificity. In conclusion, the SI-R3 and SI-R9 were successfully developed from the original scale, we hope that clinicians and researchers will benefit from reduced administration time, improved compliance, and more cost-effectiveness, and this will lead to greater use in clinical and research settings.