A Longitudinal Examination of Outcome Expectancy Constructs and their Role in Type 1 Diabetes in Youths

Abstract

This study was designed to test the associations between outcome expectancy constructs (i.e., hope, optimism, and self-efficacy) and health outcomes (i.e., HbA1c and self-monitored blood glucose [SMBG]) among youths with type 1 diabetes mellitus. It was hypothesized that hope, optimism, and self-efficacy would be significantly associated with each construct in longitudinal models, such that outcome expectancy constructs would statistically predict change in health outcomes approximately 6-months after baseline assessments. 110 participants (mean age = 13.6) completed the Children's Hope Scale (CHS), the Life Orientation Test-Revised (LOT-R; optimism measure), and the Self-Efficacy for Diabetes Scale (SED), and their HbA1c and SMBG data were obtained from chart review during their clinic visit. 81 of the original 110 participants completed the assessment battery at time 2 (6-month follow-up). Confirmatory factor analyses were conducted on all measures, and the results confirmed the factor structure of the CHS and the LOT-R, but did not support the factor structure of a three-factor model, or more parsimonious one-factor model. The limited follow-up data restricted statistical power for tests of longitudinal associations using structural equation modeling (SEM), but a cross-sectional model using baseline data indicated a significant association between the CHS and HbA1c. Two baseline mediation models were also significant, suggesting that both the CHS and the LOT-R have significant indirect associations with HbA1c through a mediator, SMBG. Post-hoc analyses tested longitudinal associations using hierarchical multiple regression (which requires less statistical power than SEM analyses), and these analyses supported significant associations between change in CHS scores and change in HbA1c and SMBG data. This study provides further evidence of significant associations between hope and health outcomes in youths. Clinicians and researchers may benefit from incorporating hope in clinical assessments, and testing the benefit of hope-based intervention efforts in future clinical studies.