Table 1. Summary of survey measures.

Survey domain	Description	Time 1	Time 2
Participant characteristics and personality traits
Participant characteristics	Child age, parent/carer age, gender, education, number of children, ethnicity, religion and religiosity, income	✓	X
General anxiety	Generalised Anxiety Disorder Questionnaire (GAD-7). A seven-item measure for screening and severity measuring generalised anxiety disorder. Items are rated on a 4-point Likert scale 74	✓	✓
Resilience	Brief resilience scale. A six-item measure for assessing the ability to bounce back or recover from stress. Items are rated on a 5-point Likert scale 81 .	✓	X
Intolerance for Uncertainty	Short version of the Intolerance for Uncertainty scale. A 12-item measure for assessing intolerance for uncertainty. Items are rated on a 5-point Likert scale 80 .	✓	X
Attributes of informed decision-making
Knowledge	Nine-item knowledge of genome sequencing (KOGS) measure that is context-neutral and focuses on what is involved in having genome sequencing (including ‘what is a genome’), and the limitations and uncertainties of genome sequencing. Each statement is rated as either true, false or don’t know 71 . In addition, we will include a number of knowledge items developed specifically for the this study which relate to the way that the Service is being offered.	✓	X
Attitude	Five-item scale examining general attitudes to genome sequencing e.g. harmful – beneficial, unimportant – important, measured on a five-point Likert scale 18 .	✓	✓
Self-reported informed decision-making	Question used previously in survey on genome sequencing in the 100,000 Genomes Project 18 .	✓	X
Decisional conflict	Sixteen-item measure with five-point Likert scale which assess decisional certainty or conflict about a healthcare decision 73	✓	X
Decisional-regret	Five-item measure with five-point likert scale which assesses regret or remorse about a healthcare decision, with scores ranging from 0 to 100. DRS scores can be defined into three categories: no decision regret (DRS score 0), mild decision regret (DRS score 1–25), and moderate to high decision regret (DRS score >25) 69 .	X	✓
Test results	Study specific question to assess what result the patient received (a diagnostic result, a no- findings result or an uncertain result)	X	✓
Clinical, psychosocial and behavioural outcomes
Parental empowerment	Genomics Outcome Scale: six-item questionnaire with five-point likert scale which captures the theoretical construct of empowerment relating to genomic medicine 75	✓	✓
Health-related quality of life (child)	EQ-5D-Y (ages 4–15): Comprises five dimensions: mobility, looking after myself, doing usual activities, having pain or discomfort and feeling worried, sad or unhappy. Each dimension has 3 levels: no problems, some problems and a lot of problems. The caregiver (the proxy) is asked to rate the child’s/ adolescent’s health-related quality of life in their (the proxy’s) opinion 76 .	✓	✓
Psychological impact	Adapted 12-item version of the Feelings About genomic Testing Results (FACToR) with five- point Likert scale which measures the specific impact of result disclosure after genomic testing 78	X	✓
Family impact	PEDS-QL Family impact module: sixteen-item questionnaire with five-point Likert Scale which explores problems with communication, worry, daily activities, family relationships 77	✓	✓
Clinical, social and behavioural impact of results	Study specific questions which explore: changes to clinical management, understanding the likely course of the condition, changes to child’s/parent’s lifestyle, connecting with specific rare disease support groups/other families, communication with medical professionals, reproductive decision-making and identification of other at-risk family members. Each item will have 5 levels (not at all – a great deal).	X	✓
Satisfaction with appointment	Seven-item patient-satisfaction measure for use in a clinical genetics setting 79	✓	✓