Purpose:
To develop a patient-reported outcome (PRO) measure for assessing reading function in patients with geographic atrophy from age-related macular degeneration (GAAMD) and document its content validity.
Methods:
Two qualitative research studies were conducted. Entry criteria were clinician-diagnosed GAAMD, no choroidal neovascularization, age 50-85 years and visual acuity 20/50-20/400. The 1st study involved 1:1 concept elicitation interviews with 23 patients to identify functional reading activities that are problematic for these patients, and to learn how patients accommodate to their vision problems. The measure and conceptual framework were drafted based on results of the study. The 2nd study involved 1:1 cognitive interviews with 17 patients to assess whether the draft instructions, items and responses were easily understood, relevant and comprehensive. Feedback also was obtained from interviewers, clinical experts and a translational expert. The measure and conceptual framework then were revised. In both studies, interviews were audio-recorded, transcribed, coded and analyzed using ATLAS.ti software.
Results:
The resulting measure is the FRII, an interviewer-administered questionnaire with 11 items on functional reading activities most relevant to GAAMD patients: 1) reading written print, 2) reading to pay bills or write a check, 3) reading in order to take medicine, 4) reading instructions, 5) reading labels, 6) reading to play games, 7) reading to make or receive a telephone call, 8) reading words or numbers on the screen while watching television, 9) reading when using a computer, 10) reading street signs, and 11) reading signs for directions. For each reading activity, sub-items are asked about dependence on visual aids, adaptive behaviors and assistance from others to perform the activity. Item scores reflect decreasing levels of functional reading independence. The FRII is included as an exploratory outcome in a Phase Ib/II study of the safety and evidence of activity of an investigational drug in GAAMD patients.
Conclusions:
The FRII is a new PRO measure that assesses functional reading independence in GAAMD patients. A scoring algorithm is in development and Phase Ib/II study data will be used to refine the algorithm and evaluate additional measurement properties of the FRII.
Keywords: quality of life • reading • clinical (human) or epidemiologic studies: outcomes/complications