title: Evaluating the Measurement Properties of the Self-Assessment of Treatment Version II, Follow-Up Version, in Patients with Painful Diabetic Peripheral Neuropathy.
abstract: Background.The Self-Assessment of Treatment version II (SAT II) measures treatment-related improvements in pain and impacts and impressions of treatment in neuropathic pain patients. The measure has baseline and follow-up versions. This study assesses the measurement properties of the SAT II.Methods.Data from 369 painful diabetic peripheral neuropathy (PDPN) patients from a phase III trial assessing capsaicin 8% patch (Qutenza®) efficacy and safety were used in these analyses. Reliability, convergent validity, known-groups validity, and responsiveness (using the Brief Pain Inventory-Diabetic Neuropathy [BPI-DN] and Patient Global Impression of Change [PGIC]) analyses were conducted, and minimally important differences (MID) were estimated.Results.Exploratory factor analysis supported a one-factor solution for the six impact items. The SAT II has good internal consistency (Cronbach's alpha: 0.96) and test-retest reliability (intraclass correlation coefficients: 0.62-0.88). Assessment of convergent validity showed moderate to strong correlations with change in other study endpoints. Scores varied significantly by level of pain intensity and sleep interference (p< 0.05) defined by the BPI-DN. Responsiveness was shown based on the PGIC. MID estimates ranged from 1.2 to 2.4 (pain improvement) and 1.0 to 2.0 (impact scores).Conclusions.The SAT II is a reliable and valid measure for assessing treatment improvement in PDPN patients.
authors.affiliation: Astellas Pharma Global Development, Leiden, Netherlands.
authors.forename: Floortje
authors.identifier: 0000-0001-5324-6811
authors.initials: F
authors.lastname: van Nooten
authors.affiliation: Evidera, London, UK.
authors.forename: Dylan
authors.initials: D
authors.lastname: Trundell
authors.affiliation: Evidera, Bethesda, MD, USA.
authors.forename: Dorota
authors.initials: D
authors.lastname: Staniewska
authors.affiliation: Evidera, Bethesda, MD, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.affiliation: Evidera, London, UK.
authors.forename: Evan W
authors.initials: EW
authors.lastname: Davies
authors.affiliation: Evidera, Bethesda, MD, USA.
authors.forename: Dennis A
authors.initials: DA
authors.lastname: Revicki