Background: This study explored relationships among pretreatment expectations, treatment perceptions, expectation-perception difference, change in diabetes treatment satisfaction, and end point diabetes treatment satisfaction in individuals with type 2 diabetes.
Methods: Multivariate models were used to evaluate clinical and patient-reported outcomes (PRO) data from a randomized clinical trial comparing treatment algorithms for an inhaled insulin. PRO measures--Diabetes Symptom Checklist-Revised subscales, Well-Being Questionnaire 12, Diabetes Treatment Satisfaction Questionnaire, and Self-Efficacy Scale--were administered at baseline and end point. Expectations about Insulin Therapy (EITQ) and Perceptions of Insulin Therapy Questionnaires (PITQ) were administered at baseline and end point, respectively. Change scores for hemoglobin A1C (A1C), PRO (i.e., during-trial effects), and expectation-perception change were calculated. Perceptions, expectation-perception difference, and change in and end point treatment satisfaction served as dependent variables for statistical models.
Results: Complete EITQ and PITQ data were available for 240 insulin-naive individuals with type 2 diabetes (mean age, 58 years; 61% male; 78% white; mean baseline A1C, 8.4%). Treatment perceptions were significantly (P < 0.01) more positive than expectations. After controlling for baseline patient assessments and during-trial effects, regression analyses showed that pretreatment expectations independently contributed to perceptions (beta = 0.18, P = 0.001) and expectation-perception change (beta = -0.71, P < 0.001). Acting as a suppressor variable, pretreatment expectations enhanced the ability of expectation-perception difference to predict both change in (beta = 0.39, P < 0.001) and end point (beta = 0.57, P < 0.001) diabetes treatment satisfaction.
Conclusions: Pretreatment expectations and expectation-perception difference play an important role in the amount of change that occurs in satisfaction with new treatment as compared to that of previous treatment, as well as satisfaction with new treatment.