title: The contribution of pretreatment expectations and expectation-perception difference to change in treatment satisfaction and end point treatment satisfaction in the context of initiation of inhaled insulin therapy in patients with type 2 diabetes.
abstract: 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.
authors.affiliation: Global Health Outcomes, Eli Lilly and Company, Indianapolis, Indiana 46285, USA. hayes_clarice@lilly.com
authors.forename: Risa P
authors.initials: RP
authors.lastname: Hayes
authors.forename: April N
authors.initials: AN
authors.lastname: Naegeli
mesh_terms: D000280:Administration, Inhalation; D000368:Aged; D000465:Algorithms; D001786:Blood Glucose; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D007328:Insulin / Q000008:administration & dosage* / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D010465:Perception; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin