A Study to Assess Choroideremia (CHM) Health Outcomes

Primary outcomes

1. Time to Disease Progression by Age in Participants with CHM

   Time frame: Up to 8 months

2. Best Corrected Visual Acuity by Age

   Time frame: Up to 8 months

   Best corrected visual acuity will be used as an indicator to assess disease severity.

3. Participants with CHM: EuroQol- 5 Dimension- 5 Level (EQ-5D-5L) Score

   Time frame: Up to 8 months

   EQ-5D is a self-report measure of health for clinical and economic appraisal. Participants complete the 5-level (no problems, slight problems, moderate problems, severe problems, and extreme problems), 5-dimension (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) questionnaire concerning their current health state. A unique EQ-5D-5L health state scale ranges from 0 to 100 and is defined by combining 1 level from each of the 5 dimensions. Participants indicate their current health status by marking on a continuum ranging from 100 (best imaginable health state) to 0 (worst imaginable health state). The questionnaire will be implemented only one time per person in the study duration.

4. Participants with CHM: Health Utilities Index (HUI3) Score

   Time frame: Up to 8 months

   Health Utilities Index (HUI3) is a family of generic preference-based systems for measuring comprehensive health status and health-related quality of life (HRQL). HUI® provides descriptive evidence on multiple dimensions of health status, a score for each dimension of health, and a HRQL score for overall health. Health dimensions include vision, hearing, speech, ambulation/mobility, pain, dexterity, self-care, emotion and cognition. Each dimension has 3- 6 levels. HUI® systems describe almost a million unique health states. HUI3 score ranges from 0.36 (worst) to 1 (best). The questionnaire will be implemented only one time per person in the study duration.

5. Participants with CHM: Work Productivity and Activity Impairment (WPAI) Score

   Time frame: Up to 8 months

   The Work Productivity and Activity Impairment (WPAI) is a 6 questionnaire scale used to measure lost work productivity and impairment in daily activities over the past seven days. The WPAI yields four types of scores: 1. Absenteeism 2. Presenteesism 3. Work productivity loss 4. Activity Impairment, ranging from 0-100%. Higher numbers indicate greater impairment and less productivity. The questionnaire will be implemented only one time per person in the study duration.

6. Participants with CHM: Visual Function Questionnaire (VFQ-25) Score

   Time frame: Within 8 months

   VFQ-25 is a reliable and valid 25-item version of the 51-item National Eye Institute Visual Function Questionnaire (NEI-VFQ). It is especially useful in settings such as clinical trials, where interview length is a critical consideration. The global score derives from the summary of the scores deriving from each question. The total score has a minimum value "0" considered as the worst visual functionality, and the maximum value "100" considered as the better visual functionality. The questionnaire will be implemented only one time per person in the study duration.

7. Resource Utilization in Participants with CHM

   Time frame: Up to 8 months

   Healthcare Resource Utilization will be assessed by number of primary care provider visits, specialist visits, urgent care visits, emergency room (ER) visits, hospitalizations, and rehabilitation visits in past 12 months when stratified by all-cause & CHM-related.

8. Caregivers of Participants With CHM: Caregiver-reported Depression Via Patient Health Questionnaire-9 (PHQ-9) Score

   Time frame: Up to 8 months

   PHQ-9 can be used to screen for or diagnose depression, as well as measure depression severity. The PHQ-9 measures frequency of depression symptoms, with items scored on a 4-point scale (not at all=0 to nearly every day=3). The total score ranges from 0-27 where 0 is no depression and 27 is severe depression. The questionnaire will be implemented only one time per person in the study duration.

9. Caregivers of Participants With CHM: Caregiver-reported Anxiety Via General Anxiety Disorder-7 (GAD-7) Score

   Time frame: Up to 8 months

   GAD-7 is a 7-item questionnaire that is used for screening, diagnosing, monitoring, and measuring the severity of anxiety. Each item can be answered on a 4 point scale running from 0= 'not at all sure' to 3= 'nearly every day'. The total score ranges from 0-21 where 0 is no anxiety and 27 is severe anxiety. The questionnaire will be implemented only one time per person in the study duration.

10. Caregivers of Participants With CHM: Caregiver Reaction Assessment (CRA) Score

    Time frame: Up to 8 months

    Caregiver Reaction Assessment is a 24-item instrument assessing positive and negative aspects of caregiving (esteem, lack of family support, finances, schedule, and health). Each item is rated on a 1 to 4 scale. 1 (not at all) 2 (somewhat) 3 (quite a bit) 4 (completely). The questionnaire will be implemented only one time per person in the study duration.

11. Caregivers of Participants With CHM: Work Productivity and Activity Impairment Caregiver (WPAI-CG) Score

    Time frame: Up to 8 months

    WPAI-CG is a 6 questionnaire scale used to measure lost work productivity and impairment in daily activities over the past seven days. The WPAI yields four types of scores: 1. Absenteeism 2. Presenteesism 3. Work productivity loss 4. Activity Impairment, ranging from 0-100%. Higher numbers indicate greater impairment and less productivity. The questionnaire will be implemented only one time per person in the study duration.