Table 1.

Instruments Administered in the Study

Type of Measure	Instrument	Description	Score Metrica	Meaning of a Higher Score
PROMIS® Measures Evaluated for Responsiveness
Physical Health
	PROMIS® Fatigue v1.0	Assesses fatigue from mild subjective feelings of tiredness to an overwhelming, debilitating, and sustained sense of exhaustion that is likely to decrease one’s ability to carry out daily activities, including the ability to work effectively and to function at one’s usual level in family or social roles.	IRT T-score	More fatigue
	PROMIS® Physical Function v1.2	Assesses one’s ability to carry out activities that require physical actions, ranging from self-care (activities of daily living) to more complex activities that require a combination of skills, often within a social context.	IRT T-score	Better physical function
	PROMIS® Sleep Disturbance v1.0	Assesses perceptions of sleep quality, sleep depth, and restoration associated with sleep; perceived difficulties and concerns with getting to sleep or staying asleep; and perceptions of the adequacy of and satisfaction with sleep	IRT T-score	Greater sleep disturbance
	PROMIS® Sleep-related Impairment v1.0	Assesses perceptions of alertness, sleepiness, and tiredness during usual waking hours, and the perceived functional impairments during wakefulness associated with sleep problems or impaired alertness	IRT T-score	Greater sleep-related impairment
Mental Health
	PROMIS® Depression v1.0	Assesses negative mood, negative views of self, negative social cognition, and decreased positive affect and engagement	IRT T-score	More depression
	PROMIS® Anxiety v1.0	Assesses fear (e.g., fearfulness, feelings of panic), anxious misery (e.g., worry, dread), hyperarousal (e.g., tension, nervousness, restlessness), and somatic symptoms related to arousal (e.g., racing or pounding heart, dizziness).	IRT T-score	More anxiety
	PROMIS® Cognitive Function v1.0/v2.0b	Assesses a person’s perception of functional abilities with regard to cognitive tasks in areas such as concentration, memory and mental acuity, including perceptions regarding change in one’s cognitive ability.	IRT T-score	Better cognitive function
Social Health
Social Function
	PROMIS® Ability to Participate in Social Roles and Activities v2.0	Assesses the perceived ability to perform one’s usual social roles and activities.	IRT T-score	Fewer limitations (better ability to participate in social roles)
	PROMIS® Satisfaction with Social Roles and Activities v2.0	Assesses satisfaction with performing one’s usual social roles and activities.	IRT T-score	Greater satisfaction.
Social Relationships
	PROMIS® Social Support v2.0: Emotional Support Informational Support Instrumental Support	Three measures that assess functional aspects of supportive relationships: - Emotional (Perceived feelings of being cared for and valued as a person; having confidant relationships) - Informational (Perceived availability of helpful information or advice) - Instrumental (Perceived availability of assistance with material, cognitive or task performance)	IRT T-score	More support
Measures Used as Responsiveness Indicators (Anchors)
Patient-Reported Outcomes
	Kansas City Cardiomyopathy Questionnaire (KCCQ-12)	Assesses heart failure-specific health-related quality of life (HRQOL); four subscales/domains and an overall summary score: - Physical Limitation - Symptom Frequency - Quality of Life - Social Limitation - Overall	Sum score: 0 to 100	Better HRQOL
	EuroQOL Five-Dimension, Three-Level (EQ-5D-3L)	Assesses generic health status; five dimensions: - Mobility - Self-care - Usual Activities - Pain/Discomfort - Anxiety/Depression Visual Analogue Scale (VAS) of Overall Health	Ordinal scale for each dimension: no problems, some problems, extreme problems VAS: 0 to 100	Each dimension: extreme problems VAS: best imaginable health.
	PROMIS® Global Health v1.1	Evaluations of health in general; 4 items: - Quality of Life (02) - Mental Health (04) - Usual Social Activities and Roles (09) - Bothered by Emotional Problems (10)	Ordinal scale: Poor to Excellent Poor to Excellent Poor to Excellent Always to Never	Better Health
	Global Ratings of Change	Five retrospective assessments of change by the patient, who is asked to state whether they have experienced change from pre-implant to the present (3 months post-implant): - Physical Function - Quality of Sleep - Anxiety - Mood - Social Activities and Roles	A lot better, A little better, About the same, A little bit worse, A lot worse	Worse change
Clinician Rating
	NYHA Functional Classification	Clinician rating of how severely symptoms of heart failure limit physical activity	Ordinal scale: No limitation, Slight limitation, Marked limitation, Unable to carry on any physical activity without discomfort	Worse heart failure-related functional status
Performance Test
	6-Minute Walk Test	Assessment of functional capacity during a 6-minute walk in an enclosed hallway, which is free of traffic and distractions	Meters walked	Greater functional capacity

^aScore metric: Information about how the instrument is scored

^bAlthough two versions of this measure were used, the scoring was recalibrated to be comparable.

Item Response Theory (IRT) T-score: mean=50, standard deviation=10

sum score: aggregated item responses