Table 1.

Persons with multimorbidity key assessment domains and measures.^a

Domain	Scale or measure	Description of measure	Assessment time point
Demographics	Self-report questionnaireb	7 self-report items collecting information on gender; date of birth; marital status; educational level; living alone or with others; employment status; primary occupation	T1
Medication list	Self-report list	Interviewer recorded a list of the names, dosage, and frequency of each participant’s medications. These data were used to initially populate the triage system for nurses, who then managed the ongoing collection and updated medication information	T1
Comorbidity index/disease burden	Multimorbidity assessment by self-report [26]b	22-item list of common conditions or comorbidities: yes or no to indicate presence of conditions; then 5-point Likert scale to assess the extent to which each condition limits daily activities	T1 and T4
Technology use and proficiency	Mobile device proficiency questionnaire [27]b	16-item scale to assess older adults’ proficiency with mobile technological devices. Participant-rated ability to carry out different operations (internet, calendar, etc) on a 5-point Likert scale	T1 and T4
Cognitive function	Montreal cognitive assessment [28]	30-item scale measuring cognitive function in several domains; total score gives measure of global cognition; cognitive screening test	T1 and T4
Health related quality of life/health outcome measure	The 5-level EuroQol-5D version [29]	5-item self-report Likert scale: rate level of problems in five dimensions: mobility, self-care, usual activities, pain or discomfort, and anxiety or depression 1-item visual analogue scale: own judgment of health status between 1 and 100 (from “best health you can imagine” to “worst health you can imagine”)	T1, T2, T3, and T4
Quality of life	Control, Autonomy, Self-Realization and Pleasure-19 [30]	19-item scale measuring quality of life across four dimensions: control, autonomy, pleasure, and self-realization. Developed for an older adult population.	T1, T2, T3, and T4
Illness perceptions	Multimorbidity Illness Perceptions Scale [31]b	22-item scale measuring illness perceptions related to multimorbidity in five dimensions: emotional representations, treatment burden, prioritizing conditions, causal links, and activity limitation	T1, T2, T3, and T4
Self-efficacy	General self-efficacy scale [32]	10-item self-report Likert scale: assesses perceived self-efficacy and ability to cope with daily hassles and stressful life events	T1, T2, T3, and T4
Locus of control	Multidimensional health locus of control scale [33]	18-item scale assessing beliefs about control individuals have over their own health in three main dimensions: internal control, chance, and power	T1, T2, T3, and T4
Social connectedness	Lubben social network scale [34]	18-item version to measure social connection in three domains: family, friends, and neighbors	T1 and T4 (18 item); T2 and T3 (6 item)
Depression and anxiety	Hospital Anxiety and Depression Scale [35]	14-item scale to measure depression and anxiety—developed as a screening tool for clinical levels of depression and anxiety	T1 and T4
Sleep quality	Pittsburgh Sleep Quality Scale [36]	9-item scale to assess subjective sleep quality: can provide an overall score and domain specific scores	T1 and T4
Fatigue	Functional Assessment of Chronic Illness Therapy Fatigue Scale [37]b	13-item scale measuring feelings of fatigue, weakness, or energy and impact on daily activities	T1 and T4
Physical activity	Rapid Assessment of Physical Activity [38]	10-item scale to measure engagement in physical activities	T1 and T4
Usability	System Usability Scale [39]	10-item scale (Likert scale item) to provide subjective assessment of the usability of a technology system	T2, T3, and T4
User burden (technology)	User Burden Scale [40]b	18-itemc self-report scale used to evaluate user burden when engaging with technology. Likert scale	T2, T3, and T4

^aMeasures administered at each assessment time point are a subset of those listed in this table; an indication of the time point for each assessment is indicated in the table below.

^bThese measures were included as part of a paper-based questionnaire sent to participants in advance of the relevant interview.

^cThe original questionnaire has 20 items, but two questions in relation to financial burden were not used due to lack of relevance.