The development and psychometric testing of the shared decision-making instrument

Abstract

Immunizations are a primary prevention intervention to prevent communicable diseases. The human papillomavirus (HPV) vaccine has been available to females in the United States since June 2006. However, the receipt of the HPV vaccine is suboptimal with only 50% of 13 to 15 year old females initiating the HPV vaccine and less than 25% completing the recommended series. The majority of HPV infections resolve spontaneously, however, some HPV types persist and predispose to cervical, vaginal, vulvar, or anal cancer. Healthy People 2020 established a goal that 80% of 13 to 15 year old females complete the HPV vaccine series. Previous research has focused on the medical provider and parents influence on HPV vaccine receipt and have excluded the school nurse who regularly manages the healthcare of females between 11 and 12 years of age. To fill this gap in knowledge, the aim of this research was to develop a psychometrically sound, theoretically based instrument to assess the four Shared Decision-Making (SDM) constructs of knowledge, attitude, self-efficacy, and intent. The study sample of 1525 school nurses who were members of the National Association of School Nurses completed the SDM Inventory-Revised (SDMI-R) instrument. Proportions, correlation matrixes, Cronbach alpha, and principle component analysis with direct oblimin rotation were the primary methods used to determine the psychometric properties of the SDMI-R. The correlational matrixes indicated moderate to strong correlations between items, indicating adequate internal reliability. The overall reliability of the SDMI-R was judged to be very good (α = .874) with the three theoretically derived subscales (attitude, self-efficacy, and intent) achieving Cronbach's alpha of .828, .917, and .891, respectively. The exploratory factor analysis revealed five components that explained 75.96% of the variance. While additional confirmatory analysis is required, the SDMI-R instrument will describe SDM perceptions of school nurse in nurse-client encounters. Resulting data will provide information for state and national nursing organizations to advocate with public policy makers for safe and effective preventive school health services. The SDMI-R has promise for advancing the understanding of SDM abilities of school nurses and to test interventions provided by school nurses to establish evidence-based SDM standards.