Psychometric Evaluation of the Allergan Satisfaction with Treatment Experience Questionnaire (ASTEQ) Using Data from a Phase 3B Study of an Intraocular Implant for Open-Angle Glaucoma (OAG) and Ocular Hypertension (OHT)

Speaker(s)

Naik R1, Christie WC2, Wallace D3, Kolko M4, Cai K5, Hallak J5, Huang JT5, Maram J5, Nguyen A5, McGinley JS6, Houts C7, Thomas FA2, Paauw J8
1Noesis Healthcare Technologies, Inc.,, Redwood City, CA, USA, 2Scott & Christie and Associates, Cranberry Township, PA, USA, 3Thomas Eye Group, Sandy Springs, GA, USA, 4University of Copenhagen, Copenhagen, Denmark, 5Allergan, an AbbVie company, Irvine, CA, USA, 6Vector Psychometric Group, LLC, Chapel Hill, NC, USA, 7Vector Psychometric Group, LLC, Lakewood, OH, USA, 8Piedmont Eye Center, Lynchburg, VA, USA

Presentation Documents

OBJECTIVES: To evaluate psychometric properties and establish a scoring algorithm for ASTEQ, a 9-item patient-reported outcome measure, designed to quantify patient satisfaction with sustained-release bimatoprost implant treatment in OAG/OHT. Satisfaction with the implant experience, bother from side effects, worry about procedure/potential risks, and physical discomfort are captured.

METHODS: Data from the bimatoprost 10-µg implant phase 3b trial (NCT03850782) collected at 12 weeks and 8 months after first injection were analyzed. Items involving repeat injections were excluded. Dimensionality assessments (exploratory and confirmatory factor analyses) focused on satisfaction items. Internal consistency reliability, convergent/discriminant correlations (item scores with relevant reference variables), known-groups analyses, and responsiveness to change were assessed.

RESULTS: Included were 313 participants who had received one bimatoprost 10-µg implant. Dimensionality assessment and internal consistency analyses did not support creation of an ‘overall satisfaction’ summary score. However, individual ASTEQ satisfaction items displayed test-retest correlations from 0.63 (worry about the implant) to 1.00 (long-term side effects) indicating the ASTEQ items, except the 'worry' items, produced reliable scores over time. Observed correlations with reference variables at both time points supported discriminant validity (e.g., visual acuity [r range = -0.11 to 0.10]) for all items and convergent validity (e.g., Treatment Satisfaction Questionnaire for Medication [TSQM] Global domain scores with ASTEQ overall satisfaction item [r=-.51, week 12; -.49, month 8]; TSQM Side Effects domain with ASTEQ long-term sides effects item [r=-.38, week 12; -.49, month 8]). Known-groups and responsiveness analyses also supported ASTEQ items as stand-alone measures.

CONCLUSIONS: The ASTEQ items are reliable and valid for evaluating satisfaction, bother, and physical discomfort in patients with OAG/OHT receiving bimatoprost implant. While a summary score from the ASTEQ items was not empirically supported, individual items are face-valid assessments and can be used as stand-alone measures, especially for satisfaction and short- and long-term side effects.

Code

PCR153

Topic

Methodological & Statistical Research, Patient-Centered Research

Topic Subcategory

Instrument Development, Validation, & Translation, PRO & Related Methods

Disease

Sensory System Disorders (Ear, Eye, Dental, Skin)