The Self-Management Instrument for Breast Cancer Patients undergoing Adjuvant Therapy (SMAT-B): Development and Psychometric Testing using the COSMIN Methodology

ObjectiveThis study aims to develop and test the Self-Management instrument for breast cancer patients undergoing Adjuvant Therapy (SMAT-B).MethodsAfter a qualitative interview with 29 two rounds of Delphi expert consultation 15 experts, 49 items were initially generated. Before item reduction, another structured was conducted content validity. Item analysis exploratory factor (n=377) used reduction. After that, internal consistency, split-half reliability, test-retest reliability (n=30), measurement error, construct validity, structural validity (n=342) preliminarily evaluated using COnsesus-based Standards selection health Measurements INstruments guidelines (COSMIN methodology).ResultsThe final version SMAT-B includes 7 dimensions 31 after The testing results suggested that had good consistency (Total Cronbach’s α=0.952), (Spearman-Brown coefficient=0.904), stability ICC=0.797), acceptable error (SEM=5.28), (SRMR=0.055). hypotheses all verified certain extent (r>0.20, P < 0.01).ConclusionsThe 31-item SMAT-B, developed in interviews demonstrated psychometric properties can be recommended researchers clinicians further evaluation self-management ability patients.Trial RegistrationChiCTR2100052868.