Promoting Mental and Cognitive Health in Old Age Through Scalable Evidence-based Interventions

Measurement tool: EuroQol Five-Dimensional Five-Level Scale (EQ-5D-5L; Herdman et al., 2011); Unit of measure: EQ-5D-5L index score (country-specific value set; range: -0.661 to 1.000 for Germany). Higher values on the EQ-5D index indicate better health status.

Measurement tool: Capability Index for Older People, Scale (ICECAP-O; Gustafsson & Horder, 2022; Coast et al., 2008); Unit of measure: The ICECAP-O assesses five core dimensions of well-being relevant to older adults (attachment, security, role, enjoyment, control). ICECAP-O scores on the five core dimensions range from 1 to 4, with 1 being the lowest and 4 being the highest. These raw scores are then converted to tariff scores, ranging from 0 (representing absence of capability) to 1 (representing full capability).

Measurement tool: Kessler Psychological Distress Scale (K6; Kessler et al., 2002); Unit of measure: K6 total score ranges from 0 to 24, with higher values indicating greater psychological distress.

Measurement tool: Geriatric Depression Scale - Short Form, Scale (GDS-SF; Sheikh & Yesavage, 1986); Unit of measure: GDS-SF total score ranges from 0 to 15, with higher scores indicating higher levels of depression.

Measurement tool: Geriatric Anxiety Inventory - Short Form, Scale (GAI-SF; Byrne & Pachana, 2010); Unit of measure: The GAI-SF total score ranges between 0 to 5, with higher scores representing higher anxiety levels.

Measurement tool: Brain Care Score, Scale (self-designed scale based on Singh et al., 2023; Livingston et al., 2020; Ngandu et al., 2015); The Brain Care Score assesses six key dimensions known to be related to brain health: exercise, cognitive stimulation, social engagement, stress, sleep, and nutrition. Scores on the six dimensions range from 1 to 5. The total score ranges from 6 to 30, with higher scores indicating a lifestyle more supportive of brain health.

Measurement tool: EuroQol Five-Dimensional Five-Level Scale (EQ-5D-5L; Herdman et al., 2011); Unit of measure: EQ-5D-5L index score (country-specific value set; range: -0.661 to 1.000 for Germany) and Visual Analog Scale (VAS; range: 0-100). Higher values on the EQ-5D index indicate better health status, and higher values on the VAS also indicate better perceived health.

Measurement tool: EuroQol Five-Dimensional Five-Level Scale (EQ-5D-5L; Herdman et al., 2011); Unit of measure: Visual Analog Scale (VAS; range: 0-100). Higher values on the VAS indicate better perceived health.

Measurement tool: Cognitive Telephone Screening Instrument, Scale (COGTEL, online version: E-COGTEL; Kliegel et al., 2007); Unit of measure: The total COGTEL score is derived from the sum of the weighted scores of each of the six subtests. A high score indicates better global cognitive functioning.

Measurement tool: Raven Advanced Progressive Matrices - Short Form, Scale (APM; Arthur & Day, 1994; Raven et al., 1985); Unit of measure: The APM total score ranges from 0 to 12 points, with higher scores indicating a higher general cognitive ability.

Measurement tool: Subjective Cognitive Complaints Questionnaire (self-designed; Geerlings et al., 1999; Jessen, 2010; EIlis et al., 2014); Unit of measure: This instrument consists of five yes/no items that assess both perceived memory decline and related concerns.

Measurement tool: Perceived Experiences of Age Discrimination Scale (PAD; De Paula Couto et al., 2023); Unit of measure: The PAD total score ranges from 0 to 4, with higher scores indicating a greater frequency or intensity of perceived age discrimination.

Measurement tool: Age-related Stereotype Threat Scale (not yet published version); Unit of measure: Higher total scores indicate greater age-related stereotype threat.

Measurement tool: Generalized Self-Efficacy Scale (GSE; Jerusalem & Schwarzer, 1992); Unit of measure: The total GSE score ranges from 10 to 40, with higher values indicating a stronger generalized sense of self-efficacy.

Measurement tool: Subjective Aging Perception Scale (SAPS; De Gracia et al., 1999); Unit of measure: The SAPS assesses four dimensions of individuals' perceptions and attitudes toward their own aging process (perceived self-care, perceived social resources, cognitive self-competence, perceived time structure). Scores on the four dimensions vary between 3 and 20, with higher scores indicating more positive perceptions of aging.

Measurement tool: Lubben Social Network Scale - 6 items (LSNS-6; Lubben et al., 2006); Unit of measure: The total LSNS-6 score ranges from 0 to 30. Higher scores indicate a larger, more active social network and stronger social connections.

Measurement tool: De Jong Gierveld 6-item Loneliness Scale (DJGLS-6; De Jong Gierveld & Van Tilburg, 2006); Unit of measure: The DJGLS-6 total score ranges from 1 to 5, with higher scores indicating greater loneliness.

Measurement tool: Senior Technology Acceptance Model - Short Form, Scale (Short STAM; Chen & Lou, 2020); Unit of measure: The Short STAM total score ranges from 14 to 140, with higher scores indicating greater technology acceptance.

Measurement tool: Cognitive Reserve Index questionnaire, Scale (CRIq; Nucci et al., 2012); Unit of measure: The total CRIq score is standardized: the average is 100, with a standard deviation of 15. Higher values indicate greater cognitive reserve.

Measurement tool: MacArthur Scale of Subjective Social Status, Scale (MacArthur SSS Scale; Adler et al., 2000); Unit of measure: The MacArthur SSS score ranges from 1 to 100, with higher values indicating a higher perceived social status.

Measurement tool: Client Service Receipt Inventory (CSRI; Chisholm et al., 2000); Unit of measure: Different questions gather information on health and social care service use, informal care, employment and income, living situation and housing, as well as medication and treatment adherence. This information will be used to estimate total costs per participant over the past two months.

Measurement tool: Facilitator Attendance Logs; Unit of measure: Number of attended sessions: ranges from 0 to 10, with higher numbers indicating greater session attendance.

Measurement tool: Digital platform usage data; Unit of measure: The platform gathers information on different usage markers such as number of logins, number of completed training sessions, total time spent on the platform, and number of days with at least one activity. Higher values indicate greater engagement with the digital intervention.